Asymmetric effects of a leaf‐chewing herbivore on aphid population growth

1. Plant responses to herbivory are often specific to the feeding guild of the attacking herbivore. These phytochemical responses to herbivore damage can affect herbivore performance and activity. Comprehensive studies on the ecological consequences of multi‐herbivore plant interactions are key to understanding plant–herbivore community dynamics. 2. This study examined how feeding damage by co‐occurring herbivores from separate feeding guilds, Myzus persicae (Sulzer), a sucking herbivore, and Leptinotarsa decemlineata (Say), a chewing herbivore, alter plant chemistry and indirectly affect herbivore performance. Performance was measured when each insect fed on plants individually, sequentially, or simultaneously in laboratory and field experiments. Phytohormone and glycoalkaloid content were measured for each feeding sequence to evaluate plant responses to herbivory by each guild. Mid‐season and end‐of‐season tuber yield were evaluated in the field study. 3. Damage by L. decemlineata negatively impacted M. persicae performance in both laboratory and field settings. Damage by M. persicae did not affect L. decemlineata performance in laboratory assays. However, L. decemlineata performance was positively affected by M. persicae herbivory in the field, but this effect was temporary. Although phytohormones and plant defences varied across treatments, they provide little resolution on interaction outcomes. 4. These results confirm that the presence of multiple feeding guilds on a single plant can affect these chewing and sucking herbivores differentially, but given the variability in our phytochemical analyses compared with other studies, the mechanism remains unclear. The study's findings show that aphids are negatively affected by chewing herbivores across systems, while aphids temporarily affected beetles positively.     

The domestic context of production and reproduction in a Guatemalan community

This paper investigates the relationship between fertility and domestic adjustments that people have made to changing conditions of production and consumption in a rural community in western Guatemala. Present and past systems of production and the domestic factors affecting the timing of family formation and the incidence of sexual activity within unions are described. Analyses of variance for demographic variables among three productive sectors reveals that the greatest changes in fertility over time have occurred in the families of labor-intensive garlic producers and in those of poor basketmaking specialists. The results are discussed as direct and indirect outcomes of earlier family formation due to recurrent labor crises and chronic subsistence stress.     

A case of recurrent episodes of Candida parapsilosis fungemia

Candida species is the fourth most commonly isolated organism in blood stream infections in the hospital setting. Patients with candidemia frequently succumb to this infection. For those that survive an initial candidemia, an increasing number of cases of breakthrough or recurrent candidemias have been reported in the literature. We report three episodes of C. parapsilosis fungemia in a cancer patient. Molecular testing was performed and confirmed that all these episodes occurring within an eight-month period were caused by the same organism. The incidence of recurrent candidemia is likely to increase in the near future. Studies and therapeutic interventions for patients at risk for recurrent candidemias are warranted.     

Immunological Abnormalities in Juvenile Myelomonocytic Leukaemia

Immunological studies were performed on 24 children suffering from juvenile myelomonocytic leukaemia. Strikingly high serum immunoglobulin levels with a frequent tendency towards homogeneity and light-chain imbalance were present, together with a high incidence of antinuclear antibodies (52%) and antihuman IgG antibodies (43%). Members of the families of 19 of the children were also studied. A few similar abnormalities were found in eight families, mostly clustered in four of them. The significance of the association of these immunological aberrations with juvenile myelomonocytic leukaemia is at present unknown. In view of the interrelation observed in experimental models between immunological abnormalities and oncogenic viruses the possibility of a common aetiological factor such as a viral infection during fetal life is suggested.     

Complex effects of parasitoids on pharmacophagy and diet choice of a polyphagous caterpillar

This study investigates complex effects of parasitoid infection on herbivore diet choice. Specifically, we examine how immunological resistance, parasitoid infection stage, and parasitoid taxonomic identity affect the pharmacophagous behavior of the polyphagous caterpillar, Grammia incorrupta (Arctiidae). Using a combination of lab and field experiments, we test the caterpillar’s pharmacophagous response to pyrrolizidine alkaloids (PAs) over the course of parasitoid infection, as well as the effect of dietary PAs on the caterpillar’s immunological response. Previous work from other systems gave the prediction that dietary PAs would be detrimental to the immune response and thus less acceptable to feeding early in the infection, when encapsulation of the parasitoid is most crucial. We found that the feeding acceptability of PAs was indeed low for caterpillars with early-stage parasitoid infections; however, this was not explained by PA interference with immune function. When allowed to choose among three host plant species, individuals harboring early-stage parasitoids increased their consumption of a nutritious plant containing antioxidants. This result was driven by wasp-parasitized caterpillars, whereas fly-parasitized caterpillars increased their consumption of plants containing iridoid glycosides. Individuals in the later time phase of infection exhibited an increase in PA intake that was consistent with previously reported self-medication behavior during late-stage parasitoid infection. This study reveals the depth of complexity and the dynamic nature of herbivore host plant choice, and underscores the importance of considering multitrophic interactions when studying insect diet choice.     

Incidence of leukaemia and other malignant diseases following injections of the short-lived α-emitter <Superscript>224</Superscript>Ra into man

We performed an epidemiological study on 1,471 ankylosing spondylitis patients treated with repeated intravenous injections of the short lived α-emitter ²²⁴Ra (excluding radiation therapy with X-rays) between 1948 and 1975. These patients have been followed together with a control group of 1,324 ankylosing spondylitis patients treated neither with radioactive drugs nor with X-rays. The mean follow-up time was 26.3 years in the exposed and 24.6 years in the control group. To date, causes of death have been ascertained for 1,006 exposed patients and 1,072 controls. Special emphasis was placed on the reporting of malignant diseases. Expected numbers of cases were computed for the age, sex and calendar year distribution of both groups using cancer registry incidence rates. In the exposed group 18 cases of kidney cancer (vs. 9.1 cases expected, P < 0.01) and 4 malignant thyroid tumours (vs. 1.2 cases expected, P = 0.03) were observed. In the control group the observed cases for these tumours were not significantly elevated. The most striking observation, however, were the 21 cases of leukaemia in the exposed group (vs. 6.8 cases expected, P < 0.001) compared to 12 cases of leukaemia in the control group (vs. 7.5 cases expected). Further sub-classification of the leukaemias demonstrated a high increase of myeloid leukaemia in the exposed group (12 cases observed vs. 2.9 cases expected, P < 0.001), and out of these, especially a high excess of acute myeloid leukaemias (7 cases observed vs. 1.8 expected, P = 0.003). In the controls the observed cases are within the expected range (4 myeloid leukaemias vs. 3.1 cases). This increase in total leukaemias as well as particularly in myeloid leukaemias is significant in direct comparison between the exposed and control groups too (P < 0.05). The enhanced leukaemia incidence in the exposed group is in line with the observation of increased leukaemia incidence in mice injected with ²²⁴Ra.     

Phenotypic diagnosis of primary immunodeficiencies in Antioquia,Colombia, 1994-2002

Recurrent infections are a frequent cause of medical visits. They can be due to a heterogeneous group of dysfunctions that increase the susceptibility to pathogenic and opportunistic microorganisms, such as immunological deficiencies. To define an opportune rational treatment and to guide the molecular diagnosis of primary immunodeficiency diseases, we establish a program for the phenotypic diagnosis of these illnesses in Antioquia, Colombia, including clinical and laboratory evaluations of patients who present recurrent infections with abnormal evolution. Between August 1, 1994 and July 31, 2002, phenotypic diagnosis of primary immunodeficiency was made in 98 patients. Similar to data reported in the literature, antibody deficiencies were the most frequent (40.8%), followed by combined deficiencies (21.4%). This phenotypic characterization has allowed for appropriate treatments for each patient and, in some cases, functional and molecular studies that can lead to a definite molecular diagnosis.     

Intestinal candidiasis. A clinical report and comments about this opportunistic pathology

An eight-years-old girl, who presented with recurrent upper respiratory tract infections, was treated with broad-spectrum antibiotics. Afterward she presented with intestinal candidiasis. The isolated species was identified as Candida albicans by differential tests. Treatment given was with 500,000 IU of oral nystatin every 8 hours for 10 days and intestinal normal microbiota restoratives. Evolution has been satisfactory, although concomitantly type A hepatitis developed. Rest and a soft diet were recommended. The child is now perfectly healthy with normal liver function tests. Conclusion: Prolonged treatments with broad-spectrum antibiotics destroyed the indigenous intestinal microbiota, which provoked intestinal C. Albicans proliferation and adversely affected the immunological system of the patient, thus facilitating the establishment of a viral infection.This revised version was published online in October 2005 with corrections to the Cover Date.     

Reliability of the serological method of examination as a basis for diagnosis of associated respiratory virus infections.

The reliability of the results of serological examination in diagnostics of associated infections was studied on a model of artificially provoked vaccinal infections in humans and in laboratory animals. The effect of administered monopreparations on changes in the level of both homologous and heterologous antibodies was tested. The character of immunological changes following simultaneous administration of two or more respiratory viruses was analysed and the effect of these viruses in diseases of divers etiology was studied. According to the results of experiments on laboratory animals, repeated administration of any of the earlier used respiratory viruses stimulated the accumulation of only homologous antibodies while heterologous antibodies did not increase at all. The results revealed the possibility of simultaneous immunological reorganization of a child's organism in response to the influence of several different antigens from the group of respiratory viruses acting synchronously or in succession. Results of the analysis demonstrated the reliability of the employed serological methods of diagnosis of respiratory virus infections.     

Dynamics of heterozygosity and its correlation with fitness in a population of domestic pigs

Variation of heterozygosity at 11 loci for blood group systems (erythrocyte antigens), occurred during 14 years in the domestic pig population of Kemerovskaya breed is described. The two estimates computed for the population examined were represented by expected population heterozygosity, as a measure resistant to stochastic fluctuations, and individual heterozygosity, as a measure with the features of a quantitative trait. Our results showed that relative fitness of genotypic classes, formed by the alleles of erythrocyte antigen loci, was different. It was demonstrated that the population examined carried the alleles responsible for fitness decrease, as well as the alleles with stable and unstable equilibrium points (with increased and decreased relative fitness of heterozygotes). Suggestions based on these results, could be applied not only to the population examined, but also to the domesticated form of Sus scrofa as a whole.     

Forecasting infections of the red rot disease on Porphyra yezoensis Ueda (Rhodophyta) cultivation farms

Pythium porphyrae is a fungal pathogen responsible for red rot disease of the seaweed Porphyra (Rhodophyta). Infection forecasts of Porphyra by P. porphyrae were estimated from the epidemiological observations of Porphyra thalli and numbers of zoospore of P. porphyrae in laboratory and cultivation areas. Four features of forecasting infections were determined by relating zoospore concentrations to the incidence of thallus infection; infection (in more than 1000 zoospores L⁻¹), microscopic infection [less than 2 mm in diameter of lesion (in from 2000 to 3000 zoospores L⁻¹)], macroscopic infection [more than 2 mm in diameter of lesion (in from 3000 to 4000 zoospores L⁻¹), and thallus disintegration (in more than 4000 zoospores L⁻¹). High zoospore concentrations led to more infection. The tendency that zoospore concentration of P. porphyrae increased with the rate of infection of Porphyra thalli was generally observed in forecasting infections in both the laboratory and in cultivation areas. Based on the Porphyra cultivation areas, the accuracy and consistency of forecasting infections suggest that this method could be employed to manage and control red rot disease.     

Laboratory and Field Studies on Glugea stephani (Hagenmuller), a Microsporidan Parasite of Pleuronectid Flatfishes*

SYNOPSIS. The microsporidan Glugea stephani is a common parasite of juvenile English sole (Parophrys vetulus) in Yaquina Bay, Oregon. Field observations indicated that fish became infected only in the upper estuary where summer temperatures were above 15 C and the incidence of infection reached 79.8% in the late fall. Laboratory infections developed and parasite growth occurred only at or above 15 C. The parasite was successfully transmitted to juvenile English sole by brine shrimp (Artemia salina) and amphipod (Corophium spinicorne) vectors as well as by direct ingestion of spores by the host. Infections that resulted from ingestion of spore-carrying vectors were much heavier than those resulting from the direct ingestion of spores. The speckled sanddab (Citharichthys stigmaeus), a nonpleuronectid flatfish, and chum salmon (Oncorhynchus keta) were refractory to G. stephani infection in the laboratory. Results of this study suggest that G. stephani is potentially lethal to young pleuronectid flatfishes when heavy infections involve the entire intestine and reduce the capacity to absorb nutrients. Under these circumstances, starvation is probably the direct or indirect cause of death. The restriction of infection to fish that reach the upper estuary very likely mitigates the impact of G. stephani caused mortality on the entire English sole population on the Yaquina Bay nursery ground.     

Immunological features in multiple sclerosis.

A clinical and laboratory profile of the immunological system of patients with multiple sclerosis (MS) strongly suggested that many specific immune deficiencies exist in MS. The immunological history showed that patients with MS had had more tonsillectomies, appendicectomies, and childhood infections than matched controls, which suggested that there had been problems in controlling various types of childhood infections. The cell-mediated immune response and the circulating antibody titres were specifically impaired against a variety of antigens. Patients with MS had significantly lower serum antibody titres than controls against many naturally occurring antigens-namely, diptheria and tetanus toxoids, adenovirus, and mumps viruses. Raised serum antibody titres were found against measles and varicella zoster viruses while no difference was found towards other antigens. The delayed hypersensitivity reaction and the immunological memory of patients with MS were also greatly reduced against the mumps skin test antigens. There were normal amounts of circulating T and B lymphocytes, and the phytohaemagglutinin, concanavallin A, pokeweed mitogen, and encephalitogens lymphocyte transformation was not different from that in controls. These results indicated that patients with MS have more infectious problems than normal people and that both their T and B cell systems cannot mount a fully normal immunological response to some viral and bacterial antigens, while they give an increased response to others.     

The influence of the testa, damage and seed dressing on the emergence of groundnut (Arachis hypogea)

The effects of damaging the testa and the application of seed dressings were examined in field trials on several short-and long-season cultivars of groundnut (Arachis hypogea) with differently-pigmented testas at Samaru, Nigeria, in 1967. There was a high correlation between the number of seedlings which emerged in these trials and the resistance or susceptibility of the seed to invasion by the fungus Aspergillus flavus, as assessed by laboratory tests. When the testa was undamaged the emergence of white (susceptible) seed was only 50% while that of coloured (resistant) seed was between 95 and 98%. Damage to the testa by scratching greatly decreased emergence. The application of seed dressing increased the emergence of susceptible seed and also restored the emergence of scratched seeds to the level of undamaged seeds. The effect of the complete removal of the testa was not counteracted by seed dressing; naked seeds, with and without dressing, gave c. 10% emergence. The importance of pigment in the testa, the condition of the seed and the effects of seed dressing are discussed.     

Arg753Gln Polymorphism of the Human Toll-like Receptor-2 Gene in Children with Recurrent Febrile Infections

Polymorphisms in toll-like receptors (TLRs) have been reported to increase susceptibility for some diseases. TLR-2 gene polymorphisms in Turkish children with recurrent respiratory tract infections and without well-known humoral immunodeficiencies were examined. The study consisted of 52 children with recurrent infections (study group) and 91 healthy children with a maximum of two infections in a year (control group). Recurrent infection was defined as the presence of at least six febrile bacterial infection episodes in a year. Not only TLR-2 gene polymorphisms but also immunoglobulins (IgG, IgM, IgA), IgG subsets (G1, G2, G3), and specific antibody levels (anti-tetanus and anti-hemophilus influenza) were determined to exclude humoral immunodeficiencies. The Arg753Gln and Arg677Trp polymorphisms were genotyped by polymerase chain reaction restriction fragment length polymorphism. The Arg753Arg genotype was significantly decreased in the study group compared to the control (P < 0.05). Children with recurrent infections were also found to be more frequently Arg753Gln heterozygous (P < 0.05), and their Gln allele distribution was higher than that of the control subjects (23% vs. 4.9%; P < 0.001). In contrast to these results, we did not detect any case with Arg677Trp polymorphism in both groups. These results have indicated that there is a strong significant relationship between susceptibility to recurrent bacterial infections and Arg753Gln polymorphism of the TLR-2 gene.     

Associations between the two serum proteins haptoglobin and transferrin and leukaemia

Haptoglobin and transferrin (TF) types were determined for 134 patients with leukaemia of the four most common types: acute lymphocytic (ALL), chronic lymphocytic (CLL), acute myelocytic (AML) and chronic myelocytic leukaemia (CML). The phenotype HP1 was found to have an increased incidence in the total patient group due to an increased incidence in those with AML, ALL and CML compared with controls, but not in those with CLL. Although tests of association applied to each of the samples of the four common types of leukaemia produced no significant chi 2 values, they did indicate that the relative incidence (RI) was just under 2 for the groupings of the acute forms ALL and AML, the myelocytic forms AML and CML and for the combination of ALL, AML and CML, respectively. All these associations were statistically significant (p less than 0.05). Analysis of TF subtypes and leukaemia indicated a significantly increased frequency of TF C1C1 among leukaemia patients compared with controls (p less than 0.005). Analysis of the samples of each of the four common types suggested that while the RI was raised in all but ALL patients, the association was significant only in AML patients (p less than 0.05). However, when the two myelocytic types were combined the RI was 2.3 and the association was highly significant (p less than 0.005). No such association could be detected in the lymphocytic forms.     

The role of different slug species in damage to oilseed rape bordering on sown wildflower strips

Damage caused by different slug species on above and below ground parts of young oilseed rape bordering on sown wildfower strips was studied. Slug densities and damage were recorded in the field and damage rates for each slug species were measured in the laboratory. Severe slug damage was observed in rape areas 1 m from the wildflower strips. Damage rates of slug species feeding above ground were distinctly higher than those feeding below ground. The estimated damage caused by above-ground feeding in all four study fields ranged between 72% and 89 % and was always distinctly higher than damage caused by below-ground feeding (11% to 28 %). The estimated damage caused by Arion lusitanicus above ground was between 54% and 69 %, followed by Deroceras reticulatum (3% to 26 %). Thus A. lusitanicus was responsible for the majority of damage in the rape crops studied.     

Childhood leukaemia in the West Berkshire and Basingstoke and North Hampshire District Health Authorities in relation to nuclear establishments in the vicinity.

During the years 1972-85, 89 children aged 0-14 were registered with leukaemia in the West Berkshire and Basingstoke and North Hampshire District Health Authorities. Two nuclear establishments are located within the health authorities, and a third is situated nearby. Fifty of the 143 electoral wards in the two district health authorities lie wholly within, or have at least half their area lying within, a circle of radius 10 km around the establishments. In those 50 electoral wards 41 children aged 0-14 were registered with leukaemia, 28.6 registrations being expected on the basis of leukaemia registration rates in England and Wales (incidence ratio = 1.4, p less than 0.05). This excess was confined to children aged 0-4, among whom there were 29 registrations of leukaemia, 14.4 being expected (incidence ratio = 2.0, p less than 0.001). In the remaining 93 electoral wards there was a small and non-significant increase in the number of registrations of leukaemia at age 0-14 (48 observed, 40.8 expected; incidence ratio = 1.2). There was no obvious trend in the incidence of childhood leukaemia over the 14 years and the overall occurrence of the malignancy in the 143 electoral wards was consistent with a random distribution. In the surrounding Oxford and Wessex Regional Health Authorities the number of registrations of leukaemia at age 0-14 was virtually identical with that expected on the basis of registration rates in England and Wales (362 observed, 372.5 expected; incidence ratio = 1.0). These data indicate that in the two district health authorities studied there was an excess incidence of childhood leukaemia during 1972-85 in the vicinity of the nuclear establishments. In the West Berkshire and Basingstoke and North Hampshire District Health Authorities an average of 60,000 children aged 0-14 lived within a 10 km radius of a nuclear establishment each year. The normal expectation of leukaemia in these children was two cases a year, whereas the recorded incidence was three cases per year, representing one extra case of leukaemia each year among these 60,000 children.     

Virulence Attenuation of Candida albicans Genetic Variants Isolated from a Patient with a Recurrent Bloodstream Infection

The incidence of Candida albicans infections and the relapse episodes after antifungal treatment have increased in recent decades. Recurrences are mainly due to the persistence of the original infecting strain that may present genetic and genomic rearrangements during interaction with the host, reflecting strain adaptation. In this study, four isolates recovered from a patient during recurrent candidemia episodes were genotyped by microsatellite length polymorphism (MLP) and by multilocus sequence typing (MLST) and found to be genetic variants of the same strain. Using experimental mouse infections, a progressive reduction in the virulence of the four isolates was observed, with the first two isolates more virulent than the third and fourth. Additionally, in the mouse model, the first isolate resisted host control more efficiently, resulting in higher kidney fungal burdens and necrosis as compared to the third isolate. The resolution of inflammation was delayed in mice challenged with the first isolate and the message for IFN-γ and TNF-α in the spleen was lower within the first few hours post-infection. Original and recurrent isolates also displayed different phenotypes regarding activity of secreted enzymes and response to stress agents. Overall, the comparative analysis indicated that the virulence decrease of these isolates was related to a lower ability to resist to the host anticandida effector mechanisms. We showed for the first time that C. albicans genetic variants of the same strain, sequentially isolated from an immunocompromised patient, underwent adaptations in the human host that resulted in virulence attenuation when tested in mice.     

Co-infection of Dengue,Zika and Chikungunya in a group of pregnant women from Tuxtla Gutiérrez,Chiapas: Preliminary data. 2019

IntroductionDengue, Zika and Chikungunya are RNA Arboviruses present in some areas of Mexico, mainly in the endemic state of Chiapas that is characterized by presence of the vector that transmit them and an ecology that favors high transmission. According to the national epidemiological surveillance system, Dengue has intensified since 2018 and outbreaks continue in various states while for Zika and Chikungunya a decrease in cases has been reported in recent years. The main objective of this study was to determine the incidence of Dengue, Zika and Chikungunya infections during pregnancy in the state of Chiapas.Principal findingsThe presence of previous and current infections and coinfections diagnosed by molecular (RT-PCR) and immunological (ELISA for IgG determination) techniques indicates a wide circulation of viruses in asymptomatic people, specifically in pregnant women showing that silent infections in dry season contributes to the preservation of viruses.ConclusionsFrom 136 studied samples, 27.7% tested positive for DENV, 8% for ZIKV and 24.1% for CHIKV by RTPCR and the values of IgG in sera show that 83.9% were positive for IgG antibodies against DENV, 65% against ZIKV and 59.1% against CHIKV. Results demonstrated presence of ZIKV and CHIKV, not detected by the epidemiological surveillance system, so the importance of establishing proactive epidemiological systems more strict, especially because these infections in pregnant women can cause severe health problems for newborn children.