Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Malignant melanoma and pregnancy

Confusion exists concerning the influence of pregnancy on survival in patients with malignant melanoma. To evaluate this problem a retrospective computer-aided study was performed of women in the child-bearing years treated for Stage I cutaneous melanoma at the Duke University Comprehensive Cancer Center. Fifty-eight women were identified who had melanoma arise during pregnancy (Group 1) and 43 patients were noted who became pregnant within 5 years of diagnosis of their melanoma (Group 2). Appropriate control groups matched for the clinical variables of age, primary site, and stage of disease and the pathologic variables of Clark's Level, tumor thickness, ulceration, and histologic type were selected from the cohort of 2938 melanoma patients seen at Duke. Actuarial survivals for Group 1 and 2 patients did not differ from their respective controls, although the small number of deaths in each group resulted in wide confidence intervals. When actuarial disease-free intervals were plotted, there was a significant difference between women who had melanoma develop during pregnancy when compared to their controls (P = 0.04). In a multivariate regression analysis, after adjustment for the influence of the more significant prognostic factors for Stage 1 melanoma, including Clark's Level, ulceration and tumor thickness, the effect of pregnancy on disease-free interval became more apparent (P = 0.02). No difference in actuarial disease-free interval was noted in the melanoma patients who elected to become pregnant within 5 years of diagnosis (P = 0.31). A multivariate regression analysis confirmed this finding. These data indicate that although an intercurrent melanoma during pregnancy has a worse prognosis than the control groups, once a woman has been diagnosed as having a cutaneous melanoma, a subsequent pregnancy has no effect on recurrence rate or survival.

Immunotherapy of recurrent genital herpes with recombinant herpes simplex virus type 2 glycoproteins D and B: results of a placebo-controlled vaccine trial

To determine the safety, immunogenicity, and efficacy of a recombinant herpes simplex virus type 2 glycoprotein D and B vaccine in the treatment of recurrent genital herpes, a randomized, placebo-controlled trial was held at two referral centers. Healthy patients with 4-14 recurrences per year received injections of both glycoproteins in MF59 adjuvant or of MF59 alone at 0, 2, 12, and 14 months. For 18 study months, the rate and number of recurrences, the duration and severity of the first confirmed recurrence, vaccine immunogenicity, and rates of local and systemic reactions were determined. The monthly rate of recurrences was not significantly improved, but the duration and severity of the first study outbreak was reduced significantly by vaccination. Glycoprotein-specific and neutralizing antibodies were boosted by vaccination for the duration of the study. This vaccine is safe and immunogenic and ameliorated an observed first postvaccination genital recurrence, but it does not reduce recurrence frequency.

Prognostic factors in metastatic and hormonally unresponsive carcinoma of the prostate

Eighty-eight patients with hormone-resistant Stage IV prostate cancer were treated with a five-drug chemotherapy program. Patient demographic data, prior therapy, symptoms, extent of disease, and laboratory studies were analyzed statistically to evaluate the association of these parameters with survival from the onset of chemotherapy. Factors associated with short survival included age greater than 65, severe bone pain, poor performance status, presence of soft tissue metastases, anemia, elevation of serum LDH, SGOT, alkaline and acid phosphatases, and prolactin, and hypoalbuminemia. Race, stage at initial diagnosis, prior radiation therapy, prior orchiectomy, and elevation of CEA had no prognostic association. We suggest that clinical trials of new therapies of hormone-resistant prostate cancer take into account the presence of these prognostic factors in the analysis of the results of therapeutic programs.

Receptor-dependent immune responses in pigs after oral immunization with F4 fimbriae

F4 receptor-positive (F4R+) and F4 receptor-negative (F4R-) pigs were orally vaccinated with purified F4 fimbriae of enterotoxigenic Escherichia coli (ETEC). Serum immunoglobulin G (IgG) and IgA responses were readily detected in F4R+ animals, whereas immune responses were not detected in F4R- animals. Even after a subsequent oral infection with virulent F4(+) ETEC and a booster immunization with F4, the F4R- animals remained F4 seronegative whereas the unvaccinated F4R+ pigs exhibited clear IgA and IgG responses. These results clearly demonstrate that F4Rs are a prerequisite for an immune response following oral immunization. Furthermore, indications that oral F4 vaccination can induce mucosal protection were obtained, since the experimental ETEC infection did not induce a systemic booster response or fecal ETEC excretion in orally vaccinated F4R+ pigs, in contrast to the clear immune response and ETEC excretion of unvaccinated F4R+ animals. F4-specific IgA antibodies could be found in the feces of the vaccinated F4R+ pigs. They are secreted at the intestinal mucosal surface and appear to prevent ETEC infection. The F4R-dependent induction of a mucosal immune response can be used as a model to better understand mucosal immunization and mucosal immune responses and can contribute to the development of oral vaccines in veterinary as well as in human medicine.

Carbon and chlorine isotope fractionation during aerobic oxidation and reductive dechlorination of vinyl chloride and cis-1,2-dichloroethene

The study investigated carbon and chlorine isotope fractionation during aerobic oxidation and reductive dechlorination of vinyl chloride (VC) and cis-1,2-dichloroethene (cDCE). The experimental data followed a Rayleigh trend. For aerobic oxidation, the average carbon isotope enrichment factors were -7.2 per thousand and -8.5% for VC and cDCE, respectively, while average chlorine isotope enrichment factors were only -0.3 per thousand for both compounds. These values are consistent with an initial transformation by epoxidation for which a significant primary carbon isotope effect and only a small secondary chlorine isotope effect is expected. For reductive dechlorination, larger carbon isotope enrichment factors of -25.2 per thousand for VC and -18.5 per thousand for cDCE were observed consistent with previous studies. Although the average chlorine isotope enrichmentfactors were larger than those of aerobic oxidation (-1.8 per thousand for VC, -1.5 per thousand for cDCE), they were not as large as typically expected for a primary chlorine isotope effect suggesting that no cleavage of C-Cl bonds takes place during the initial rate-limiting step. The ratio of isotope enrichment factors for chlorine and carbon were substantially different for the two reaction mechanisms suggesting that the reaction mechanisms can be differentiated at the field scale using a dual isotope approach.

Correlation Between Type of Adaptive Immune Response Against Porcine Circovirus Type 2 and Level of Virus Replication

Porcine circovirus 2 (PCV2) replication is characterized by high variation among infected pigs. This study investigated the role of immunologic responses in causing this variation. Twelve gnotobiotic pigs were inoculated with PCV2. Four of these pigs were treated with cyclosporin A (CysA) to monitor the effect of the adaptive immunity on the development of the PCV2 infection. Through lymph node biopsies at 10, 15, and 21 days postinoculation (DPI), PCV2 replication in lymphoid tissues was monitored. The production of total PCV2-specific and PCV2-neutralizing antibodies was followed, together with interferon-gamma (IFN-gamma) mRNA expression levels in peripheral blood monocytes as a marker for cellular immunity. In general, the CysA-treated pigs showed the highest PCV2 titers, indicating that the adaptive immunity is necessary to restrain PCV2 replication. Three different PCV2 replication patterns were observed in non-CysA-treated pigs. Pattern 1: In two pigs, PCV2 was not detected. They had the highest neutralizing antibody titers, appearing from 15 DPI. In these pigs a good cellular response was indicated by a peak in IFN-gamma mRNA at 15 DPI. Pattern 2: Five pigs contained low to moderate PCV2 titers at 15 DPI, remaining constant or decreasing towards 21 DPI. Lower neutralizing antibody titers were observed and no rise in IFN-gamma was detected. Pattern 3: In one pig, a low PCV2 titer at 15 DPI dramatically increased toward 21 DPI. Although an antibody response against PCV2 was mounted, no PCV2-neutralizing antibodies were detected. This pig also showed no rise in IFN-gamma. The study findings indicate that variation in the onset of the adaptive immunity may account for variation in PCV2 replication among pigs. Absence of PCV2-neutralizing antibodies may be an important factor in the development of an increased virus replication.

Long-term clinical outcome of immediate reconstruction after mastectomy

Immediate reconstruction of a breast removed for treatment of carcinoma can be accomplished without altering the cancer-ablative surgical procedure. The theoretical possibility that reconstruction might compromise the cure rate has tempered enthusiasm for this approach. To test this issue, the relapse-free survival of 101 patients who underwent breast reconstruction in the immediate postmastectomy period was compared with that of 377 patients with breast cancer who underwent mastectomy without immediate reconstruction. This comparison was accomplished using multivariable statistical techniques to correct for baseline inequalities between the patient groups. After adjustment for the relevant prognostic factors, no significant difference remained between the two groups. We conclude that immediate reconstruction has no discernible adverse influence on the natural history of surgically treated breast carcinoma.

Induction of immune responses in pigs following oral administration of purified F4 fimbriae

An effective way of stimulating the mucosal immune system was examined in piglets, using F4 fimbriae of enterotoxigenic Escherichia coli (ETEC). It was demonstrated that purified F4 fimbriae, as opposed to ovalbumin (OVA), are powerful oral immunogens. Indeed, oral administration of purified F4 induced antigen-specific antibody-secreting cells (ASC) in the Peyer's patches, mesenteric lymph nodes (LN), blood and lamina propria 4, 7, 9 and 11 days postimmunization, respectively, indicating a stimulation of the mucosal immune system, whereas upon oral administration of OVA, no immune response was observed. Moreover, the induced F4-specific IgA and IgG antibody responses were comparable with those obtained upon oral infection with viable E. coli and intramuscular (i.m.) F4 injection, respectively. Furthermore, a priming of the mucosal immune system is better obtained by oral infection (ASC localized in mesenteric LN) than by i.m. F4 injection (ASC localized in spleen and retropharyngeal LN) since an oral boost with purified F4 induced a secondary response in the orally infected animal (mainly IgA and IgG ASC, rapid increase of IgA antibodies) while in the i.m. primed animal a secondary (more circulating antigen-specific ASC than in the unprimed animal) as well as a primary IgM and IgA response (mainly IgM ASC, slow increase of IgA antibodies), suggesting a primary mucosal response, were seen. An oral challenge of the naive control displayed a primary response (mainly IgM ASC, slow increase of IgA and IgG antibodies). The capacity of purified F4 to activate the mucosal immune system on oral administration, is of importance for the development of oral vaccines against ETEC infections.

The F4 fimbrial antigen of Escherichia coli and its receptors

F4 or K88 fimbriae are long filamentous polymeric surface proteins of enterotoxigenic Escherichia coli (ETEC), consisting of so-called major (FaeG) and minor (FaeF, FaeH, FaeC, and probably FaeI) subunits. Several serotypes of F4 have been described, namely F4ab, F4ac, and F4ad. The F4 fimbriae allow the microorganisms to adhere to F4-specific receptors present on brush borders of villous enterocytes and consequently to colonize the small intestine. Such ETEC infections are responsible for diarrhea and mortality in neonatal and recently weaned pigs. In this review emphasis is put on the morphology, genetic configuration, and biosynthesis of F4 fimbriae. Furthermore, the localization of the different a, b, c, and d epitopes, and the localization of the receptor binding site on the FaeG major subunit of F4 get ample attention. Subsequently, the F4-specific receptors are discussed. When the three variants of F4 (F4ab, F4ac, and F4ad) are considered, six porcine phenotypes can be distinguished with regard to the brush border adhesiveness: phenotype A binds all three variants, phenotype B binds F4ab and F4ac, phenotype C binds F4ab and F4ad, phenotype D binds F4ad, phenotype E binds none of the variants, and phenotype F binds F4ab. The following receptor model is described: receptor bcd is found in phenotype A pigs, receptor bc is found in phenotype A and B pigs, receptor d is found in phenotype C and D pigs, and receptor b is found in phenotype F pigs. Furthermore, the characterization of the different receptors is described in which the bcd receptor is proposed as collection of glycoproteins with molecular masses ranging from 45 to 70 kDa, the bc receptor as two glycoproteins with molecular masses of 210 an 240 kDa, respectively, the b receptor as a glycoprotein of 74 kDa, and the d receptor as a glycosphingolipid with unknown molecular mass. Finally, the importance of F4 fimbriae and their receptors in the study of mucosal immunity in pigs is discussed.

Different kinetic of antibody responses following infection of newly weaned pigs with an F4 enterotoxigenic Escherichia coli strain or an F18 verotoxigenic Escherichia coli strain

To develop a vaccine against Escherichia coli-induced post-weaning diarrhea and edema disease, insights in the induction of the protective immune response following infection with these pathogenic E. coli is needed. Therefore, the fimbriae-specific antibody response of newly weaned pigs following infection with the Shiga-like toxin type II variant (SLT-IIv) producing F18(+) verotoxigenic E. coli (VTEC) (strain 107/86) was compared with the response following an infection with LT producing F4(+) enterotoxigenic E. coli (ETEC) (strain GIS 26). F4(+) ETEC were able to colonize the gut very soon after infection, as peak excretion of F4(+) E. coli bacteria was seen 2 days post-infection (dpi), but had already disappeared 7dpi. On the other hand, F18(+) VTEC infection resulted in a slower colonization of the gut as the peak excretion of F18(+) E. coli was observed between 3 and 5dpi, but this colonization remained longer as F18(+) E. coli were detected till 9dpi in feces. Furthermore, this fast colonization pattern of F4(+) ETEC is accompanied with the presence of F4-specific antibodies in mucosal tissues and serum from 4dpi onward, with maximal amounts of F4-specific IgA in the jejunal lamina propria and serum 7dpi. In contrast, F18-specific IgA was only readily detected in the jejunal lamina propria 15dpi and showed a maximum serum titer 21dpi. Besides this faster induction and higher antibody response, the switch from IgM to IgA and IgG was also earlier following the F4(+) ETEC infection.

Malignant melanoma in the elderly

Advancing age is associated with poorer prognosis in malignant melanoma. We studied 3,872 cases of malignant melanoma to evaluate whether the effect of age could be analyzed relative to sex, tumor depth, primary site, and other clinical and pathologic variables. The sex distribution by age shows a slight female predominance in the early and late decades but male predominance in the middle years. The percentage of patients with metastatic disease at initial diagnosis did not vary with age, despite greater diameter and depth of lesions in the older patients. In fact, in the older age groups, initial nodal metastasis occurred slightly less frequently. Trunk primaries decreased in frequency with increasing age, while extremity lesions remained relatively constant, and face, nose, and ear lesions increased. This was in part related to the histopathologic type, as lentigo maligna lesions increased in frequency with age, superficial spreading lesions were somewhat less frequent in the older age group and nodular types were fairly constant. On the basis of both Clark's level and Breslow thickness, there was an increasing proportion of deeper penetrating lesions in the older age group. The mean diameter of these lesions on the skin surface was also greater for the older patients. This would suggest that lesions in the older individual remain confined to the local site longer, penetrate and spread, but do not necessarily metastasize more rapidly. Cox model regression analysis of survival time within stage showed that age was highly significant as a poor prognostic factor. Though the adverse relation of advancing age with survival was partially explained by predominance of other unfavorable factors, such as primary site, depth of lesion, or histologic type, age remained an independent poor prognostic factor (chi 2 = 5.3; P = .02) for death due to melanoma.

Receptor-specific binding of purified F4 to isolated villi

Different procedures for preparing and purifying F4ac fimbriae of the enterotoxigenic Escherichia coli strain GIS 26 (O149:K91:F4ac LT+Sta+STb+) were performed and the purity and yield of F4ac were compared. Fimbriae were prepared by either mechanical shearing or heatshock treatment of concentrated bacterial suspensions (10(11) bacteria/ml). The mechanical shearing procedure resulted in approximately 1.7 mg fimbriae (i.e. 74.4% of the isolated protein) and 0.6 mg (25.6%) contaminating proteins per 10(12) bacteria, whereas the yield of fimbriae following heatshock treatment was lower (0.3 mg per 10(12) bacteria, i.e. 26.2%) and the relative contamination higher (1.0 mg per 10(12) bacteria, i.e. 73.8%). A further purification consisted of either anion exchange chromatography (AEC) or electro-elution from SDS-polyacrylamide gels. The electroelution procedure was performed under reducing and denaturing conditions, so that purified FaeG subunits, the major subunit of F4, were finally obtained. The binding activity of fimbriae, nonpurified as well as purified, and FaeG to F4-specific receptors on isolated intestinal villi was assessed in an inhibition adhesion assay. Native fimbriae as well as major subunits were able to bind to the receptors, and the specificity of the binding was demonstrated by blockage with F4ac-specific MAb.

Efficacy of patient letter reminders on cervical cancer screening: a meta-analysis

OBJECTIVE

To perform a meta-analysis on existing randomized controlled trials to investigate the efficacy of patient letter reminders on increasing cervical cancer screening using Pap smears.

METHODS

A search was conducted for all relevant published and unpublished studies between the years 1966 and 2000. Eligibility criteria included randomized controlled studies that examined populations due for Pap smear screening. The intervention studied was in the form of a reminder letter. The Mantel-Haenszel method was used to measure the summary effect of the intervention. A test for homogeneity using the Mantel-Haenszel method was performed.

RESULTS

Ten articles fulfilled the inclusion criteria, including one unpublished study. The test for homogeneity showed evidence of heterogeneity (chi2 = 31, 9 df, P <.001). An analysis for causes of heterogeneity was pursued. Division into subpopulations based on socioeconomic status resolved the heterogeneity (chi2 = 5.2, 8 df, P =.75). The studies evaluating those in lower socioeconomic groups had a smaller response (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.99 to 1.35) than those studies using mixed populations (OR, 2.02; 95% CI, 1.79 to 2.28). The pooled odds ratio showed that patients who received the intervention were significantly more likely to return for screening than those who did not (OR, 1.64; 95% CI, 1.49 to 1.80).

CONCLUSIONS

Patient reminders in the form of mailed letters increase the rate of cervical cancer screening. Patient letter reminders have less efficacy in lower socioeconomic groups.

Population pharmacokinetics of lamotrigine adjunctive therapy in adults with epilepsy

Plasma concentrations of lamotrigine, an antiepileptic drug obtained in three adult controlled clinical trials conducted in the United States were pooled and analyzed using NONMEM, a population pharmacokinetic computer program, to facilitate development of dosing guidelines. A total of 2,407 lamotrigine plasma concentrations from 527 patients with epilepsy were analyzed. Regression equations for oral clearance were developed as a function of body size, age (18-64 years), gender, race, and use of concomitant antiepileptic drugs. The population mean apparent oral clearance of lamotrigine in adult patients receiving one concomitant enzyme-inducing antiepileptic drug and not valproic acid was estimated to be 1 mL/min/kg. Gender and age did not affect clearance significantly. On average, clearance was reduced by 25% in non-whites and increased by 13% in patients receiving more than one concomitant enzyme-inducing antiepileptic agent. Lamotrigine did not influence the disposition of phenytoin or carbamazepine. Dosing adjustments for lamotrigine in patients receiving concomitant enzyme-inducing antiepileptic drugs and not valproic acid should not be necessary for age, gender, or the number of concomitant enzyme-inducing antiepileptic drugs. Lamotrigine does not influence the dosing requirements for phenytoin or carbamazepine.

Turkeys are protected from infection with Chlamydia psittaci by plasmid DNA vaccination against the major outer membrane protein

Plasmid DNA expressing the major outer membrane protein (MOMP) of an avian Chlamydia psittaci serovar A strain has been tested for its ability to raise an immune response and induce protection against challenge with the same serovar. A combined parenteral (intramuscular injection) and mucosal route (DNA drops administered to the nares) of DNA inoculation was compared with gene gun-based immunization. The gene gun delivery of pcDNA1/MOMP as well as the intramuscular-intranasal DNA delivery primed both T-helper and B cell memory, although rMOMP-expressing cells did not induce high antibody responses. Evidence for the priming of the memory was provided by the fact that the pcDNA1/MOMP inoculations raised antibodies belonging to the IgG and not IgM isotype. However, in response to challenge only five out of 15 vaccinated turkeys showed four-fold increases in serum IgG after challenge. By contrast, evidence for the priming of T cell memory in response to challenge was found in all vaccinated turkeys, as shown by the significantly heightened proliferative responses of peripheral blood lymphocytes following vaccination. Both immunization methods produced similar serological and lymphocyte proliferative responses. Notwithstanding the immunization method, a significant level of protection was observed in all pcDNA1/MOMP-immunized turkeys. The efficacy of MOMP-based DNA vaccination as a means of preventing severe clinical signs, lesions and chlamydia excretion in a turkey model of C. psittaci infection was demonstrated.

The age-dependent expression of the F18+ E. coli receptor on porcine gut epithelial cells is positively correlated with the presence of histo-blood group antigens

F18(+)Escherichia coli have the ability to colonize the gut and cause oedema disease or post-weaning diarrhoea by adhering to specific F18 receptors (F18R) on the porcine epithelium. Although it is well established that a DNA polymorphism on base pair 307 of the FUT1 gene, encoding an alpha(1,2)fucosyltransferase, accounts for the F18R phenotype, the F18R nature is not elucidated yet. The aim of the present study was to investigate the correlation between the presence of H-2 histo-blood group antigens (HBGAs) or its derivative A-2 HBGAs on the porcine gut epithelium and F18(+)E. coli adherence. A significant positive correlation was found between expression of both the H-2 (r=0.586, P<0.01) and A-2 (r=0.775, P<0.01) HBGAs and F18(+)E. coli adherence after examination of 74 pigs aged from 0 to 23 weeks. The majority of the genetically resistant pigs (FUT1M307(A/A)) showed no HBGA expression (91.7%) and no F18(+)E. coli adherence (83.3%). In addition, it was found that F18R expression levels rise with increasing age during the first 3 weeks after birth and that F18R expression is maintained in older pigs (3-23 weeks old). Taken together, these data suggest that, apart from H-2 HBGAs, A-2 HBGAs might be involved in F18(+)E. coli adherence.

Identification of an inhibin receptor in gonadal tumors from inhibin alpha-subunit knockout mice

Inhibins and activins are dimeric proteins that are functional antagonists and are structurally related to the transforming growth factor-beta (TGFbeta) family of growth and differentiation factors. Receptors for activin and TGFbeta have been identified as dimers of serine-threonine kinase subunits that regulate cytoplasmic proteins known as Smads. Despite major advances in our understanding of activin and TGFbeta receptors and signaling pathways, little is known about inhibin receptors or the mechanism by which this molecule provides a functionally antagonistic signal to activin. Studies described in this paper indicate that an independent inhibin receptor exists. Numerous tissues were examined for inhibin-specific binding sites, including the developing embryo, in which the spinal ganglion and trigeminal ganglion-bound iodinated inhibin A. Sex cord stromal tumors, derived from male and female inhibin alpha-subunit-deficient mice, were also identified as a source of inhibin receptor. Abundant inhibin and few activin binding sites were identified in tumor tissue sections by in situ ligand binding using iodinated recombinant human inhibin A and 125I-labeled recombinant human inhibin A. Tumor cell binding was specific for each ligand (competed by excess unlabeled homologous ligand and not competed by heterologous ligand). Based on these results and the relative abundance and homogeneity of tumor tissues versus the embryonic ganglion, tumor tissues were homogenized, membrane proteins were purified, and putative inhibin receptors were isolated using an inhibin affinity column. Four proteins were eluted from the column that bind iodinated inhibin but not iodinated activin. These data suggest that inhibin-specific membrane-associated proteins (receptors) exist.

The complex repeats of Dictyostelium discoideum

In the course of determining the sequence of the Dictyostelium discoideum genome we have characterized in detail the quantity and nature of interspersed repetitive elements present in this species. Several of the most abundant small complex repeats and transposons (DIRS-1; TRE3-A,B; TRE5-A; skipper; Tdd-4; H3R) have been described previously. In our analysis we have identified additional elements. Thus, we can now present a complete list of complex repetitive elements in D. discoideum. All elements add up to 10% of the genome. Some of the newly described elements belong to established classes (TRE3-C, D; TRE5-B,C; DGLT-A,P; Tdd-5). However, we have also defined two new classes of DNA transposable elements (DDT and thug) that have not been described thus far. Based on the nucleotide amount, we calculated the least copy number in each family. These vary between <10 up to >200 copies. Unique sequences adjacent to the element ends and truncation points in elements gave a measure for the fragmentation of the elements. Furthermore, we describe the diversity of single elements with regard to polymorphisms and conserved structures. All elements show insertion preference into loci in which other elements of the same family reside. The analysis of the complex repeats is a valuable data resource for the ongoing assembly of whole D. discoideum chromosomes.

Incidence and significance of isolation of Mycoplasma felis from conjunctival swabs of cats

Conjunctival swabs taken from 40 cats with conjunctivitis and 65 cats without conjunctivitis were examined for the presence of Mycoplasma felis. The incidence of M. felis in cats with conjunctivitis was 25%. M. felis was not isolated from clinically normal cats. Inoculation of two isolates into the conjunctival sacs of healthy cats induced conjunctival hyperemia, starting 2-3 days after inoculation and disappearing without treatment within 7 days. It is concluded that M. felis plays a role in feline conjunctivitis.

Screening of pigs resistant to F4 enterotoxigenic Escherichia coli (ETEC) infection

The present study analysed quantitatively the mucin 4 polymorphism for determining the F4ac/ab receptor status of a total of 63 pigs by comparing it with the in vitro villous adhesion assay. The probability of a susceptible genotype for the mucin 4 increases significantly with increasing F4ab or F4ac ETEC adhesion per 250 microm villi (P=0.029 for F4ab, P=0.030 for F4ac), with the odds ratio for each unit increase of F4ab or F4ac equal to, respectively, 1.036 (95% CI [1.004-1.069]) and 1.018 (95% CI [1.002-1.034]). In the phenotypic in vitro villous adhesion test, a cut-off value of 5 bacteria was chosen as a criteria for the distinction between an F4R positive and F4R negative pig. The sensitivity and specificity for the in vitro villous adhesion test, with the genotyping test for mucin 4 as golden standard, is 100% and 24%, respectively, for F4ab as well as F4ac. Absence of adhesion of F4ac and F4ab ETEC to the villous brush borders was not associated with genotypic resistance suggesting that there is at least one other receptor for F4ab/ac Escherichia coli. As a consequence, not only mucin 4 gene polymorphism but also expression of these other receptor(s) has to be included in a screening assay for F4ac/ab receptor negative pigs.

Reduced faecal excretion of F4+-E coli by the intramuscular immunisation of suckling piglets by the addition of 1alpha,25-dihydroxyvitamin D3 or CpG-oligodeoxynucleotides

In this study it was analysed whether intramuscular (IM) immunisation of piglets with F4 during the suckling period could protect against oral challenge with F4(+)-Escherichia coli and whether addition of 1alpha,25(OH)(2)D(3) or CpG-ODN could improve this protection.F4-seronegative F4-receptor positive pigs were divided into four groups of five pigs each. The pigs were intramuscularly injected with F4 fimbriae only or supplemented with 1alpha,25(OH)(2)D(3) (D(3)-group) or CpG-ODN (CpG-group). The control group received PBS in IFA. Seven days after the second immunisation, all pigs were intragastrically inoculated with 1 x 10(10) CFU of F4(+)-E. coli. All F4-injected groups, showed a reduced faecal excretion of F4(+)-E. coli. However, this reduction was only statistically significant in the D(3)-group 2 days post challenge. Pigs in the latter group showed a secondary antibody response upon challenge, indicating that F4-primed memory B-cells were present in the gut-associated lymphoid tissues at that moment.CpG-ODN, on the other hand, did not enhance the F4-specific antibody response. However, CpG-ODN significantly increased the F4-specific as well as mitogen-induced proliferation of peripheral blood monomorphonuclear cells indicating a direct or indirect overall effect on T-lymphocytes. In conclusion, supplementation with 1alpha,25(OH)(2)D(3) or CpG-ODN improved protection against an F4(+)-E. coli infection. This protection was most obvious for 1alpha,25(OH)(2)D(3) and indicates its potential use in veterinary vaccines against enteropathogens.

CpG-oligodinucleotides as an effective adjuvant in pigs for intramuscular immunizations

In this study, the effect of two oligodeoxynucleotide (ODN) sequences 5'GCT-AGA-CGT-TAG-CGT-3' (CpG-ODN) and 5'-GCT-AGA-GCT-TAG-GCT-3' (GpC-ODN) on the antigen-specific antibody and cellular immune response after intramuscular immunizations with OVA was analyzed in pigs. Pigs immunized with OVA supplemented with these ODNs showed a significantly enhanced primary antibody response in comparison with the control group which received OVA without ODN. This enhanced primary antibody response appeared ODN-sequence-independent as similar effects were seen in both ODN-groups. The OVA-specific antibody titers obtained after a single injection of antigen combined with either of both ODNs were as high as the titers in the control group after two injections. Furthermore, the ODN-supplemented animals showed significantly higher OVA-specific IgA antibodies in their saliva and nasal secretions at some time points after the first immunization. Proliferation assays showed that CpG- as well as GpC-ODN significantly enhanced the antigen-specific as well as the mitogen-induced proliferation in different lymphoid tissues. Furthermore, 48h after the third immunization the CpG-group showed a significantly decreased IL-6 mRNA expression in cells of the local draining lymph node but no significant difference in TGF-beta (Th3-like) and IL-10 (Th2-like). The ODN injected animals showed the tendency to have higher IFN-gamma (Th1-like) mRNA-expression in comparison with the control group. To our knowledge, these are the first in vivo studies in pigs, which demonstrate the appropriateness of CpG-ODN as immunostimulating adjuvants in vaccines for farm animals.