SARS coronavirus 2-reactive antibodies in bovine colostrum

Objective

To determine if bovine colostrum and sera have antibodies that react with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Animals

Dairy and beef cattle from North America and Europe, sampled before and after the SARS-CoV-2 pandemic.

Procedures

Indirect ELISAs using whole bovine coronavirus (BCoV) and SARS-CoV-2; whole SARS-CoV-2 Spike 1, Spike 2, and nucleocapsid proteins; and SARS-CoV-2-specific nucleocapsid peptide as antigens. Virus neutralization assay for BCoV. Surrogate virus neutralization assay for SARS-CoV-2.

Results

Antibodies reactive to BCoV were highly prevalent in samples collected from cattle before and after the SARS-CoV-2 pandemic. Antibodies reactive with SARS-CoV-2 were present in the same samples, and apparently increased in prevalence after the SARS-CoV-2 pandemic. These antibodies had variable reactivity with the spike and nucleocapsid proteins of SARS-CoV-2 but were apparently not specific for SARS-CoV-2.

Conclusions

Bovine coronavirus continues to be endemic in cattle populations, as indicated by the high prevalence of antibodies to the virus in colostrum and serum samples. Also, the prevalent antibodies to SARS-CoV-2 in bovine samples, before and after the pandemic, are likely the result of responses to epitopes on the spike and nucleocapsid proteins that are shared between the 2 betacoronaviruses. Cross-reactive antibodies in bovine colostrum could be examined for prophylactic or therapeutic effects on SARS-CoV-2 infections in humans.

The Imaginative Work of Craig Gosling: A Memorial Showcase

This JBC Memorial Showcase features the award-winning medical and zoological illustrations by AMI member Craig Gosling, who passed away on July 11, 2021. Craig was extremely active in the Association of Medical Illustrators. Craig was an AMI Past President and served on the Board of Governors. He received the AMI Lifetime Achievement Award, the AMI Outstanding Service Award, the Ranice W. Crosby Distinguished Achievement Award, and the Max Brödel Award for Excellence in Education.

Feeding colostrum or a 1:1 colostrum:whole milk mixture for 3 days after birth increases serum immunoglobulin G and apparent immunoglobulin G persistency in Holstein bulls

Conflicting reports exist on whether prolonged IgG consumption can further increase serum IgG in neonatal calves. Given that higher serum IgG in neonates has lifelong benefits, our objective was to determine whether serum IgG can be increased by providing multiple meals containing IgG to neonatal calves. Twenty-seven Holstein bulls were all fed 1 colostrum meal (7.5% body weight; 62 g of IgG/L) at 2 h after birth and randomly assigned to be fed (5% body weight) colostrum (COL; n = 9), whole milk (WM; n = 9), or a 1:1 colostrum:whole milk mixture (MX; n = 9) every 12 h from 12 to 72 h. Serum IgG was measured at 1, 2, 3, 6, 9, 11, and 12 h after birth. After the 12-h meal, IgG was determined at 0.5-h intervals until 16 h and then at 1-h intervals from 16 to 24 h. Serum IgG was then measured at 27 h, then every 6 h from 30 to 60 h. From 60 to 64 h, IgG was measured every 0.5 h, then at 65 and 66 h, and then every 2 h until 72 h. Serum IgG increased rapidly between 2 and 12 h for all calves. A treatment × time interaction occurred as serum IgG began to diverge between treatments after they were fed at 12 h; the interaction was greatest over the entire period for COL compared with both MX and WM and was greater for MX than for WM. Maximum IgG concentrations (C_max) were 30.4 ± 0.8, 27.2 ± 0.8, and 23.9 ± 0.8 g/L for COL, MX, and WM, respectively. Although MX C_max was equivalent to both COL and WM C_max, COL C_max was greater than WM C_max. Feeding COL and MX also prolonged the time to reach C_max. Respectively, these calves achieved C_max at 29.5 and 27.0 ± 3.4 h, whereas WM IgG peaked at 13.4 ± 3.4 h. No differences were observed for apparent efficiency of absorption between treatments from 0 to 12 h and 0 to 24 h. Immunoglobulin G area under the curve (AUC) was the same for COL and MX calves over the entire experimental period and from when treatments were fed. The IgG AUC for 0 to 72 h for WM calves was 27.4% lesser than that for COL calves but not different from MX calves. However, the IgG AUC for 12 to 72 h for WM calves differed relative to that for both COL (30.8% less) and MX (19.6% less) calves. Serum IgG concentrations were more persistent when COL (88.2 ± 2.4%) and MX (91.2 ± 2.4%) were fed rather than WM (75.3 ± 2.4%). Prolonged IgG consumption increased serum IgG concentrations, corresponding to the mass of IgG fed, and improved apparent IgG persistency in Holstein bulls. Neonatal calves should be fed at least 62 g of IgG at 12 h after birth to further increase serum IgG concentrations.

Consensus recommendations on calf- and herd-level passive immunity in dairy calves in the United States

Passive immunity in calves is evaluated or quantified by measuring serum or plasma IgG or serum total protein within the first 7 d of age. While these measurements inform about circulating concentrations of this important protein, they are also a proxy for evaluating all of the additional benefits of colostral ingestion. The current individual calf standard for categorizing dairy calves with successful passive transfer or failure of passive transfer of immunity are based on serum IgG concentrations of ≥10 and <10 g/L, respectively. This cutoff was based on higher mortality rates in calves with serum IgG <10 g/L. Mortality rates have decreased since 1991, but the percentage of calves with morbidity events has not changed over the same time period. Almost 90% of calves sampled in the USDA National Animal Health Monitoring System's Dairy 2014 study had successful passive immunity based on the dichotomous standard. Based on these observations, a group of calf experts were assembled to evaluate current data and determine if changes to the passive immunity standards were necessary to reduce morbidity and possibly mortality. In addition to the USDA National Animal Health Monitoring System's Dairy 2014 study, other peer-reviewed publications and personal experience were used to identify and evaluate potential standards. Four options were evaluated based on the observed statistical differences between categories. The proposed standard includes 4 serum IgG categories: excellent, good, fair, and poor with serum IgG levels of ≥25.0, 18.0-24.9, 10.0-17.9, and <10 g/L, respectively. At the herd level, we propose an achievable standard of >40, 30, 20, and <10% of calves in the excellent, good, fair, and poor categories, respectively. Because serum IgG concentrations are not practical for on-farm implementation, we provide corresponding serum total protein and %Brix values for use on farm. With one-third of heifer calves in 2014 already meeting the goal of ≥25 g/L serum IgG at 24 h of life, this achievable standard will require more refinement of colostrum management programs on many dairy farms. Implementation of the proposed standard should further reduce the risk of both mortality and morbidity in preweaned dairy calves, improving overall calf health and welfare.

Feeding colostrum or a 1:1 colostrum:milk mixture for 3 days postnatal increases small intestinal development and minimally influences plasma glucagon-like peptide-2 and serum insulin-like growth factor-1 concentrations in Holstein bull calves

This study evaluated how feeding colostrum- or a colostrum-milk mixture for 3 d postnatal affects plasma glucagon-like peptide-2 (GLP-2), serum insulin-like growth factor-1 (IGF-1), and small intestinal histomorphology in calves. Holstein bulls (n = 24) were fed colostrum at 2 h postnatal and randomly assigned to receive either colostrum (COL), whole milk (WM), or a 1:1 COL:WM mixture (MIX) every 12 h from 12 to 72 h. A jugular venous catheter was placed at 1 h postnatal to sample blood frequently for the duration of the experiment. Samples were collected at 1, 2, 3, 6, 9, 11, and 12 h. Following the 12-h meal, blood was collected at half-hour intervals until 16 h and then at 1-h intervals from 16 to 24 h. A 27-h sample was taken, then blood was sampled every 6 h from 30 to 60 h. Again, blood was taken at half-intervals from 60 to 64 h, then at 65 and 66 h, following which, a 2-h sampling interval was used until 72 h. Plasma GLP-2 (all time points) and serum IGF-1 (at time points: 1, 6, 12, 18, 24, 36, 48, and 72 h) were both analyzed. Duodenal, jejunal, and ileal tissues were collected at 75 h of age to assess histomorphology and cellular proliferation. Feeding COL, rather than WM, increased plasma GLP-2 by 60% for 2 h and tended to increase GLP-2 by 49.4% for 4 h after the 60-h meal. Insulin-like growth factor-1 area under the curve (from 12 to 72 h) tended to be 27% greater for COL than WM calves but was otherwise unaffected by treatment. Ileal crypts tended to proliferate more with MIX than WM, whereas ileal crypt proliferation did not differ for COL compared with MIX or WM and was not different between treatments in the proximal jejunum. Villi height was increased 1.8 and 1.5× (COL and MIX vs. WM) in the proximal and distal jejunum, respectively, whereas MIX duodenal and ileal villi height tended to be 1.5 and 1.4× that of WM. Crypt depth did not differ in any region. Surface area of the gastrointestinal tract was reduced for WM by 60 and 58% (proximal jejunum) and 38 and 52% (ileum) relative to COL and MIX and was 54% less than MIX in the distal jejunum. Overall, extended COL feeding minimally increased plasma GLP-2 and serum IGF-1 compared with WM feeding. As COL and MIX similarly promoted small intestinal maturation, feeding calves transition milk to promote intestinal development could be a strategy for producers.

1207Pulsed Field Ablation: Acute and Chronic Safety and Lesion Efficacy

Introduction

Thermal ablation methods are the cornerstone of treatment for atrial fibrillation. However, they pose a risk to extra-cardiac structures and may result in inadequate efficacy. Nonthermal, pulsed-field ablation (PFA) delivery to cardiac tissues may create durable, efficacious lesions while avoiding collateral damage.

Purpose

The purpose of this preclinical GLP study was to assess acute and chronic electrical isolation combined with a pathology assessment of chronic lesion extent in response to PFA delivery to cardiac tissue, and to document any collateral damage.

Methods

Six pigs were treated with biphasic, bipolar PFA doses through a circular multi-electrode catheter. PFA was delivered at four locations at specified voltages: superior vena cava (SVC at 700V), right atrial appendage (RAA at 1500V), left atrial appendage (LAA at 1200V), and right pulmonary vein (RPV at 1500V). Phrenic nerve pacing thresholds and electrical block at SVC, RPV, and RAA sites were investigated acutely, and electrical block at the SVC sites chronically. Pigs were survived for 4 weeks. After euthanasia, necropsies and histopathological assessments documented the findings at the lesion sites and collateral tissues.

Results

Post PFA, entrance block was achieved in all SVC, RPV, and RAA sites. Histopathology showed characteristic replacement fibrosis of the myocardium at all ablation sites. The PFA lesions in the SVC and RPV were all continuously circumferential and histopathology did not detect any remaining myofiber conduits across the post-ablation fibrosis (consistent with the electrical assessments). PFA of the appendages caused wide-ranging fibrosis in the RAA, and limited fibrosis in the LAA. Histologically, the atrial fibrosis was almost exclusively transmural in both, with the RAA lesions overall diagnosed as circumferentially complete in all but one case. The right phrenic nerve (RPN) pacing thresholds were unchanged from baseline to the end of the procedure and were all <1.0V. The examined juxtaposed RPN segments exposed to PFA at the SVC and RPV sites were normal. None of the ablated targets was associated with stenosis, aneurysms, luminal thrombus or collateral damage on the abluminal side.

Continuous lesion sites

Conclusions

This limited preclinical study evaluated the acute and chronic safety and efficacy of PFA in multiple cardiac and vascular treatment sites. In this porcine model, PFA results in acute and chronic electrical isolation, confirmed by pathology data, for all of the RPV and SVC targets. Pathology findings of the RAA revealed the ability to achieve chronic transmural lesions in highly trabeculated cardiac tissue. No collateral damage was seen to the adjacent RPN.

Acknowledgement/Funding

Medtronic

The effect of tube versus bottle feeding colostrum on immunoglobulin G absorption, abomasal emptying, and plasma hormone concentrations in newborn calves

The objective of this study was to determine if feeding colostrum to newborn calves through an esophageal tube, compared with a nipple bottle, would delay abomasal emptying, which would in turn decrease passive transfer of IgG and plasma glucose, insulin, and glucagon-like peptide (GLP) 1 and GLP-2 concentrations. Twenty newborn Holstein bull calves were fed 3 L of colostrum replacer (200 g of IgG) through either an esophageal tube or nipple bottle at 2 h after birth followed by feeding pooled whole milk every 12 h after birth. Acetaminophen was mixed into the colostrum meal as a marker for abomasal emptying. A jugular catheter was inserted 1 h after birth and blood was sampled frequently to analyze serum for IgG and acetaminophen and plasma for glucose, insulin, GLP-1, and GLP-2. Feeding method did not affect abomasal emptying, and as a result no treatment effect was present on serum IgG concentrations. Maximum concentration of serum IgG was 24.4 ± 0.40 mg/mL (± standard error), which was reached at 14.6 ± 1.88 h after the colostrum meal for both groups. Apparent efficiency of absorption at maximum concentration of IgG was 52.9%, indicating high efficiency of passive transfer of IgG for both treatments. Tube feeding increased glucose and insulin area under the curve before the first milk meal, most likely due to the decreased time to consume the colostrum meal. In addition, tube-fed calves consumed 0.5 ± 0.13 L more milk in their first milk meal than bottle-fed calves. No treatment effect on plasma concentrations of GLP-1 or GLP-2 was present, but both hormones increased after colostrum feeding. These findings confirm that there is no effect on absorption of IgG from colostrum when feeding good-quality colostrum at a volume of 3 L through either an esophageal tube or nipple bottle.

In vitro suppression of lymphocyte activation in patients with seasonal allergic rhinitis and pollen-related asthma by cetirizine or azelastine in combination with ginkgolide B or astaxanthin

Novel strategies are evaluated for management of allergic rhinitis and asthma in patients co-afflicted with both disorders. It is hypothesized that the platelet activating factor receptor antagonist ginkgolide B (GB) and the carotenoid antioxidant astaxanthin (ASX) interact with antihistamines cetirizine dihydrochloride (CTZ) and azelastine (AZE) to potentiate their ability to downregulate potentially pathological immune activation. Peripheral blood mononuclear cells from asthmatics and healthy subjects, cultured 24 hours with 50 μg/ml phytohemaglutinin (PHA) or PHA plus each drug are analyzed by flow cytometry for expression of CD25+ or HLA-DR+ by CD3+ (T cells). Results are reported as stimulation indices for CD3+CD25+ (SICD3+CD25+) and CD3+HLA-DR+ (SICD3+HLADR+) cells in cultures treated with PHA alone, versus cultures treated with both PHA and drugs. Optimal suppression of activated cells was observed in cultures stimulated with ASX 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.016; SICD3+HLADR, p = 0.012); ASX 10-6 M + AZE 10-6 M (SICD3+CD25+, p = 0.012; SICD3+HLADR, p = 0.015); GB 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.024, SICD3+HLADR+, p = 0.019). Results demonstrate improved activity of antihistamines by 2 phytochemicals, suggesting dosing strategies for animal trials of ASX- or GB-augmented formulations for seasonal allergic rhinitis and asthma.

RING finger-dependent ubiquitination by PRAJA is dependent on TGF-beta and potentially defines the functional status of the tumor suppressor ELF

In gastrointestinal cells, biological signals for transforming growth factor-beta (TGF-beta) are transduced through transmembrane serine/threonine kinase receptors that signal to Smad proteins. Smad4, a tumor suppressor, is often mutated in human gastrointestinal cancers. The mechanism of Smad4 inactivation, however, remains uncertain and could be through E3-mediated ubiquitination of Smad4/adaptor protein complexes. Disruption of ELF (embryonic liver fodrin), a Smad4 adaptor protein, modulates TGF-beta signaling. We have found that PRAJA, a RING-H2 protein, interacts with ELF in a TGF-beta-dependent manner, with a fivefold increase of PRAJA expression and a subsequent decrease in ELF and Smad4 expression, in gastrointestinal cancer cell lines (P < 0.05). Strikingly, PRAJA manifests substantial E3-dependent ubiquitination of ELF and Smad3, but not Smad4. Delta-PRAJA, which has a deleted RING finger domain at the C terminus, abolishes ubiquitination of ELF. A stable cell line that overexpresses PRAJA exhibits low levels of ELF in comparison to a Delta-PRAJA stable cell line, where ELF expression is high compared to normal controls. The alteration of ELF and/or Smad4 expression and/or function in the TGF-beta signaling pathway may be induced by enhancement of ELF degradation, which is mediated by a high-level expression of PRAJA in gastrointestinal cancers. In hepatocytes, half-life (t(1/2)) and rate constant for degradation (k(D)) of ELF is 1.91 h and 21.72 min(-1) when coupled with ectopic expression of PRAJA in cells stimulated by TGF-beta, compared to PRAJA-transfected unstimulated cells (t(1/2) = 4.33 h and k(D) = 9.6 min(-1)). These studies reveal a mechanism for tumorigenesis whereby defects in adaptor proteins for Smads, such as ELF, can undergo degradation by PRAJA, through the ubiquitin-mediated pathway.

Surface characterizations of mono-, di-, and tri-aminosilane treated glass substrates

The surface properties and structure of mono-, di-, and tri-aminosilane treated glass surfaces were investigated using surface analytical techniques including X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), and streaming potential. An optimized dip-coating process was demonstrated to produce roughly silane monolayer coverage on the glass surface. The surface charge measurements indicated that aminosilanization converts the glass surface from negative to positive potentials at neutral pH values. Higher positive streaming potential was observed for tri-compared with mono- and di-aminosilane treated glass surfaces. For all aminosilane treated glass samples, the high-resolution N 1s XPS spectra indicated a preferential orientation of the protonated amino-groups towards the glass surface whereas the free amino groups were protruding outward. This study aimed to obtain uniform, reproducibly thin, strongly adhering, internally cross-linked, and high positively charged aminosilane-coated glass surfaces for the attachment of DNA fragments used in microarraying experiments.

Porcine circovirus-2 and concurrent infections in the field

Porcine circovirus-2 (PCV-2) is the necessary cause of post-weaning multisystemic wasting syndrome (PMWS) in swine; however, a variety of co-factors, including other infectious agents, are thought to be necessary in the full expression of disease. Porcine parvovirus (PPV) was found in the inoculum used in the first experiments to reproduce PMWS in gnotobiotic swine. Retrospective and prospective studies in the field and laboratory have demonstrated PCV-2 can act synergistically with PPV to enhance the severity of PMWS. PCV-2 has been shown to play a role in the porcine infectious disease complex (PRDC). Other co-infecting agents with PCV-2 in the lung include, porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV) and Mycoplasma hyopneumoniae. Exposure of pregnant sows to PPV, PRRSV, or encephalomyocarditis virus may interact with PCV-2 infected foetuses. The severity of hepatic lesions in PCV-2 infected pigs may be enhanced by co-infection with agents such as swine hepatitis E virus and Aujezsky's disease virus. Additional studies are required to determine the mechanistic basis for the interaction of PCV-2 with other agents in the pathogenesis of the various clinical syndromes that have been associated with PCV-2 infection.

Effect of IgG therapy on lymphocyte subpopulations in the peripheral blood of Kuwaiti women experiencing recurrent pregnancy loss

Intravenously administered polyspecific IgG is being increasingly used as an immunomodulating therapy with controversial beneficial outcome. The aim of this study was to evaluate the effects of IgG infusion on peripheral T-cell subpopulations in women with recurrent pregnancy loss (RPL). Fifteen women with a history of three previous RPL between 6 and 22 weeks of gestation and positivity for the antiphospholipid antibody syndrome (APS) were randomized to one of two treatment groups: (a) an intravenous immunoglobulin therapy group (RPL-IVIg; 7 patients), 500 mg IVIg/kg/month and (b) a placebo-treated group given multivitamins (8 patients). Control groups comprised either normal pregnant women without APS (10 patients) or non-pregnant women. The T-cell markers were characterized using a monoclonal antibody panel including CD3, CD4, CD8, CD25, CD29, CD38, CD45RA, CD45RO, CD54 and HLA-DR. Analysis was performed with a two-color fluorescent-activated flow cytometer. In the first trimester, the percentage of CD4+CD25+, CD4+CD45RO+, CD8+HLA-DR+, and CD8+CD38+ populations were reduced in the multivitamin group compared to normal pregnant women (p < 0.05) while in the RPL-IVIg group only CD4+CD25+ cells were reduced (p < 0.05). By the second trimester, CD3+CD16+CD56+ was significantly higher in multivitamin- than in IVIg-treated women (p < 0.05). The percentage of CD4+HLA-DR+ was significantly higher in the two RPL groups compared to normal pregnant women (p < 0.05). IVIg therapy in women with RPL was associated with a significant reduction in CD3+CD16+CD56+ and CD4+CD25+. This may contribute to the suppression of immune-mediated processes contributing to premature abortion.

Lymphocyte subpopulations in pregnancy complicated by hypertension

The immune responsiveness of women is altered during pregnancy in order to retain protective properties against disease and at the same time allow tolerance of the fetus. Diseases such as pre-eclampsia (PE) have been suggested to arise as a result of maladaptations in these immune alterations. Here we evaluate the effect of PE on the composition of peripheral blood lymphocyte subpopulations using lymphocyte surface antigen expression. Fifty-four women of various parities with pregnancy-induced hypertension (PIH) (39 non-proteinuric and 14 proteinuric) and matched controls (30 normotensive pregnant women (NTP) and 15 healthy non-pregnant women (NP)) were investigated. Monoclonal antibodies specific for human T lymphocytes and subpopulations: CD2, CD3, CD4, CD8, CD19 and activation markers: CD25, CD45RA, CD45RO, CD54 AND HLA(-)DR were used and detected using a two-colour fluorescence analysis with an automated flow cytometer. The total number of T lymphocytes: CD2, CD3, CD4, CD8 and CD19 were significantly decreased in PIH particularly PE (P<0.05). T cells expressing NK surface markers (CD3/CD16(+)CD56) and CD4 cells expressing HLA(-)DR were higher in PE. CD8(+)HLA(-)DR(+) cells and T-helper cells expressing adhesion molecules) CD4(+)CD54(+)) were higher in NTP than in NP and PE (P<0.05, 0.05). PE is associated with elevated levels of CD4(+)HLA(-)DR(+), and CD3(+)NK cells but decreased total numbers of T lymphocytes, and the CD3(+)CD25(+) subpopulation. These findings indicate systemic alterations in maternal immunity associated with the PE state. This feature of the disease may contribute to abnormal adaptation to pregnancy resulting in PE and PIH, promoting adverse outcomes including pregnancy loss.

Role of bovine viral diarrhea virus biotype in the establishment of fetal infections

OBJECTIVE

To examine the role of bovine viral diarrhea virus (BVDV) biotype on the establishment of fetal infection in cattle.

ANIMALS

30 mixed-breed pregnant cows.

PROCEDURE

Pregnant cows were inoculated oronasally with either i-WNADL, originating from an infectious BVDV cDNA clone of the National Animal Disease Laboratory (NADL) isolate, or the parental virus stock, termed NADL-A.

RESULTS

All cows developed neutralizing antibodies to BVDV, and virus was commonly isolated from peripheral blood mononuclear cells or nasal swab specimens of NADL-A inoculated cows; however, virus was rarely isolated from specimens of i-WNADL inoculated cows. i-WNADL did not cause fetal infection, whereas all fetuses harvested from NADL-A inoculated cows at 6 weeks after inoculation had evidence of infection. Immunoblot analysis of fetal virus isolates revealed the absence of NS3, confirming a noncytopathic (NCP) biotype BVDV in the NADL-A stock. The sequence of the NCP contaminant (termed NADL-1102) and the i-WNADL genome were virtually identical, with the exception of a 270 nucleotide-long insert in the i-WNADL genome. Phylogenetic analyses revealed that NADL-1102 forms a monophyletic group with 6 other NADL genomes.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that the contaminating NCP virus in the NADL-A stock was the ancestral NADL virus, which originally infected a bovine fetus and recombined to produce a cytopathic (CP) variant. Following oronasal infection of pregnant cows, viremia and transplacental transmission of CP BVDV to the fetus is rare, compared with the high occurrence of maternal viremia and fetal infection observed with NCP BVDV.

Pregnancy-associated changes in peripheral blood lymphocyte subpopulations in normal Kuwaiti women

It has recently been reported that healthy pregnancy is associated with systemic immunosuppression. The aim of this study was to evaluate the numbers and distribution of lymphocyte subpopulations in normal, healthy pregnant Kuwaiti women. Thirty-four healthy normotensive women in the 3rd trimester of pregnancy were studied using flow cytometry to define lymphocyte subpopulations and were compared with 16 non-pregnant women. A decrease in the absolute numbers of lymphocytes was observed affecting T cells (CD3+, CD4+, CD8+), B cells (CD19+), and natural killer cells (CD16+/CD56+). When analyzed as a percentage of the total lymphocyte population, there was a significant decrease in B cells and an increase in CD4+ T cells. The T cell population revealed increased expression of CD25 on CD4+ and CD8+ cells, of HLA-DR on CD8+ cells, and of CD54 on CD4+ T cells. The reduced number of lymphocytes suggests that Kuwaiti females may be immunosuppressed in the 3rd trimester of pregnancy. The presence of activated CD4+ T cells could indicate the expression of a regulatory suppressor T cell population, as Treg cells are CD4+CD25+, and suppressor T cells are thought to be CD8+. Future work is required to explore the significance of these T cell populations in pregnancy.

Lymphocyte subpopulation frequency and presence of anti-cardiolipin and anti-nuclear antibodies in peripheral blood of Kuwaiti women experiencing recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is often associated with elevated levels of serum antiphospholipid antibodies, which contribute to the pathology of the disorder by promoting formation of thromboses, leading to placental infarction and fetal loss. Patients with recurrent pregnancy loss also exhibit pathological alterations in composition and activity of peripheral blood lymphocytes, which may be indicative of an autoimmune processes. This investigation examines the correlation between levels of anticardiolipin antibody (AC) and specific subsets of the lymphocyte repertoire in RPL patients, with the objective of further characterising the immunological basis for RPL. Non-pregnant Kuwaiti women with a history of RPL were subdivided into two cohorts based on presence or absence of elevated plasma antibodies to cardiolipin. Whole blood from these individuals was analysed by flow cytometry for selected lymphocyte subsets and compared with a non-RPL control population. When compared with controls and low AC titre subjects, women with a high AC titre exhibited significantly elevated percentages of pathogenic CD5+ B cells; two categories of activated T cells including CD4+CD25+ and CD8+CD25; NK cells and CD3+NK cells; naive (CD4+CD45RA+) cells; and transitional (CD45RO+CD45RA+) cells. In conclusion, women with elevated levels of AC antibodies possess substantially higher levels of activated T cells and pathogenic B cells, suggesting a fundamental predisposition to immune-mediated rejection of the fetus by these patients. Further characterisation of this phenomenon may allow development of novel intervention methods for management of RPL.

Antioxidant properties of calcium dobesilate in ischemic/reperfused diabetic rat retina

Calcium dobesilate possesses antioxidant properties and protects against capillary permeability by reactive oxygen species in the rat peritoneal cavity, but whether a similar action can take place in the diabetic rat retina is unknown. We investigated the oral treatment of diabetic rats with calcium dobesilate on the prevention of free radical-mediated retinal injury induced by ischemia/reperfusion (90 min ischemia followed by 3 min and/or 24 h of reperfusion). Streptozotocin-induced diabetic rats were orally treated with 50 and 100 mg/kg of calcium dobesilate for 10 days (n=12 in each group). In the first series of studies, calcium dobesilate was found to significantly reduce the maldistribution of ion content in diabetic ischemic/reperfused rat retina. Thus, in diabetic rats treated with 100 mg/kg/day calcium dobesilate, ischemia/reperfusion provoked: (i) 27.5% increase in retinal Na(+) content compared to 51.8% in the vehicle-treated group (P<0.05), and (ii) 59.6% increase in retinal Ca(2+) content compared to 107.1% in vehicle-treated animals (P<0.05). In the second series of studies, calcium dobesilate was found to significantly protect diabetic rat retina against inhibition of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase activities by ischemia/reperfusion (54% and 41% reduction, respectively, with 100 mg/kg of calcium dobesilate) and also against changes in retinal ATP, reduced glutathione (GSH), and oxidized glutathione (GSSG) contents. In the third series of experiments, rats treated with 100 mg/kg of calcium dobesilate reduced the hydroxyl radical signal intensity to 41% (measured by electron paramagnetic resonance), induced by ischemia/reperfusion in diabetic rat retina. Finally, 100 mg/kg calcium dobesilate significantly reduced retinal edema (measured by the thickness of the inner plexiform layer) in diabetic rats. In conclusion, oral treatment with calcium dobesilate significantly protected diabetic rat retina against oxidative stress induced by ischemia/reperfusion. Whether the antioxidant properties of calcium dobesilate explain, at least in part, its beneficial therapeutic effects in diabetic retinopathy deserves further investigation.

Gyrase mutants affect mutation in a localized region of Haemophilus influenzae

Spontaneous mutation was greatly increased in a localized region of the chromosome of Haemophilus influenzae, but not at other loci, by a nov gene mutation called novC that increased DNA supercoiling. Another nov gene mutation, called novD, decreased spontaneous mutation in the same localized region and depressed DNA supercoiling. Both mutations, which code for the gyrase B subunit, have been cloned, and the cloned versions also altered mutagenesis and supercoiling in a similar fashion as the two mutations on the chromosome, although novC on the plasmid caused somewhat less mutation than on the chromosome. We postulate that the effects of the gyrase B mutations on the chromosome result from their effects on supercoiling because of increased gyrase near its site of production. The fact that the novC on a plasmid does not cause mutagenesis except in the same localized region that is altered by this mutation on the chromosome, is difficult to explain. One possibility is that there is a complex of proteins in this region which is necessary for the effects on supercoiling and thus, also on mutagenesis.

MucA protein affects spontaneous mutation in a localized region of Haemophilus influenzae

A plasmid called pMucA, from a piece of the plasmid pKM101 (Mol. Gen. Genet 167 (1979) 317) cloned in the vector pDM2 (J. Bacteriol. 151 (1982) 1605), caused higher mutation in a local region of Haemophilus influenzae and caused even more mutation there in a strain also containing novC, the latter causing an increase in supercoiling (J. Bacteriol 164 (1985) 525). The novD mutation depressed supercoiling, and also depressed the mutation by pMucA in the local region of the chromosome. Thus, it is clear that supercoiling is an important phenomenon in spontaneous mutation of H. influenzae. The pMucA plasmid caused a number of other phenomena in H. influenzae, induced UV mutation (Proc. Natl. Acad. Sci. USA 82 (1985) 7753), decreased UV sensitivity of transforming DNA, but not cells, and UV-induced recombination of mutants of phage HP1c1. The effect of the MucA protein in mutagenesis of H. influenzae we consider to be due to the introduction of some of the E. coli functions from pKM101. We postulate that the localized mutation caused by the MucA plasmid also involved localization of the plasmid or its coded protein in the same area, resulting from binding to a homologous gene, probably rec-1, very close to the localized region.

Association of porcine circovirus 2 with reproductive failure in pigs: a retrospective study, 1995-1998

In order to determine if vertically transmitted porcine circovirus (PCV) has played a role in reproductive failure in pigs in areas of endemic infection, archival fixed tissues were examined by polymerase chain reaction (PCR) and immunohistochemistry. Tissues tested were from routine cases of abortion or reproductive failure submitted between 1995 and 1998 to the diagnostic laboratory at the Western College of Veterinary Medicine, Saskatoon. They originated from 29 high-health herds in the provinces of Alberta and Saskatchewan and comprised a total of 36 individual submissions. Porcine circovirus type 1 (PCV1) was not detected by PCR in any submitted tissues. Porcine circovirus type 2 (PCV2) was not detected by PCR or immunohistochemistry in any of the submitted tissue. The effect of extended formalin fixation on the detection of PCV2 by PCR was assessed and fixation for up to one week had no gross effect on sensitivity of detection using this PCR technique. Failure to detect porcine circoviruses in cases of reproductive failure prior to 1999 in areas of endemic infections, suggests that reproductive disease may be a new clinical manifestation of PCV2 infection, and that vertical transmission may not have been the primary mechanism of initial dissemination of the virus in the pig population.

In vitro effects of Ginkgolide B on lymphocyte activation in atopic asthma: comparison with cyclosporin A

The effects of Ginkgolide B (BN52021) on in vitro activation responses of human peripheral blood mononuclear cells (PBMC) from asthmatic patients was measured using 2-channel flow cytometric analysis of activation-associated cell surface antigens or ELISA assays for cytokines known to be expressed by PBMC during T1 or T2 immunological activation. BN52021 is an anti-inflammatory extract of Ginkgo biloba and has been used therapeutically. It is a known inhibitor of platelet activating factor (PAF), which is important in the pathogenesis of asthma, and may synergise with cyclosporin A (CyA) to inhibit pathogenic immune activation in asthmatics. We compared the inhibitory effects of BN52021 and CyA (1 microM each) on activation of PBMC of asthmatic patients stimulated by phorbol myristate acetate and calcium ionophore. Inhibition of production of the cytokines IL-4 and IL-5 by BN52021 was insignificant compared to CyA. However, BN52021 significantly reversed the increase in activation-associated CD45RA expression, with a trend towards decreased expression of HLA-DR. Lymphocyte activation markers were not significantly altered by CyA. Since they appear to have differing effects on activated cells, the anti-inflammatory effects of CyA and BN52021 in atopic asthma is potentially additive. The present approach may be useful for preliminary evaluation of novel therapeutic modalities for asthma treatment.

Elevated B-lymphocyte levels in lesional tissue of non-arthritic psoriasis

Psoriasis is a chronic inflammatory skin disorder characterized clinically by maculopapular skin lesions and on the cellular level by increased T-lymphocyte activation in the peripheral blood and migration of activated T-lymphocyte into the lesions. The lymphocyte subpopulations in peripheral blood from 21 Kuwaiti patients showed elevated levels of the T-lymphocyte activation marker CD25, as well as increased expression of HLA-DR compared with a group of age and sex-matched controls, confirming published findings on psoriasis. In addition, there was a tendency towards a significant increase in the CD4+/CD45RO+ (memory cell) population that was also consistent with peripheral T-lymphocyte activation. Immunohistological studies showed a heavy infiltrate of all cell types into the lesional tissue including, as expected, activated T-lymphocytes. An unexpected finding was significantly higher levels of B-lymphocytes infiltrating the psoriatic lesions; they numerically exceeded the T-lymphocyte infiltrate. This has previously been reported only in cases of psoriasis with concurrent arthritis. None of the subjects had arthritis, suggesting an immunopathological variant of psoriasis possibly specific to this population group.

Differential expression of interferon gamma by mitogen-stimulated peripheral blood mononuclear cells among Kuwaiti psoriasis patients

Most diseases exhibit characteristic profiles of cytokine expression, broadly subdivided into Th1, involving primarily cell-mediated responses, of which Interferon-gamma (INF-gamma), Interleukin-2 (IL-2) and Tumor Necrosis Factor-alpha (TNF-alpha) are hallmarks, and Th2 processes, which often involve activation of the humoral arm of the immune system, resulting in elevated levels of IL-4, IL-5 and IL-10. Psoriasis, a disorder characterized by disfiguring skin lesions and elevated levels of activated CD4+ T helper lymphocytes in both peripheral blood and lesional tissue, exhibits a profile of cytokine expression that includes high levels of TNF-alpha and IFN-gamma, with low IL-5 and IL-10, indicating that immunologically, the pathogenesis of the disease is Th1. In this study, we report the results of an investigation of peripheral blood mononuclear cell cytokine expression among Kuwaiti psoriasis patients; we demonstrated two patterns of IFN-gamma production which may suggest differing pathogeneses. Whole, haparinized blood was donated by 17 patients with active psoriasis and 11 healthy control subject. Mononuclear cells were isolated by density centrifugation and cultured for 3 days in the presence or absence of a mitogen (PHA). Supernatants were assayed for IFN-gamma (a Th1 marker) and IL-10 (a Th2 marker) by enzyme-linked immunoabsorption assay (ELISA). IFN-gamma expression by both PHA-stimulated and unstimulated cultures from psoriatics significantly exceeded that of controls (p < 0.001), whereas no significant differences in IL-10 expression were noted between psoriatic and control subjects. Stimulation indices (cytokine concentration in PHA-stimulated/unstimulated cultures, SI) for psoriatic subjects were significantly higher than those of controls for IFN-gamma (p = 0.000), but not for IL-10. Ratios of SI (SI IFN-gamma/SL IL-10) for the psoriatic subjects also were significantly greater for the psoriatic subjects than for the controls (p = 0.003). However, within the psoriatic group, eight patients failed to show the expected elevation of IFN-gamma/IL-10 ratio as a result of high unstimulated levels of IFN-gamma production. The divergence of IFN-gamma expression within the psoriatic group may indicate two different modes of T lymphocyte activation contributing to the pathogenesis of psoriasis in this study.

Reproduction of lesions of postweaning multisystemic wasting syndrome in gnotobiotic piglets

Neonatal gnotobiotic piglets were inoculated with tissue homogenates and low- and high-passage cell culture material to determine if the lesions of the newly described porcine postweaning multisystemic wasting syndrome (PMWS) could be reproduced. For this, 17 3-day-old gnotobiotic piglets were inoculated intranasally with pelleted chloroform-treated, filtered extracts from cell cultures, filter-sterilized homogenates of lymphoid tissue from PMWS-affected piglets, or control materials. Piglets were maintained in germ-free isolators for up to 5 weeks after infection prior to euthanasia and collection of samples for analysis. All piglets inoculated with the viral inocula developed lesions typical of PMWS, including generalized lymphadenopathy, hepatitis, nephritis, interstitial pneumonia, myocarditis, and gastritis. Porcine circovirus (PCV), as well as porcine parvovirus (PPV), was detected in tissues by virus reisolation, polymerase chain reaction analysis, or immunohistochemistry. All infected piglets developed moderate to high titers of antibody to PCV and moderate titers to PPV. No lesions, virus, or virus-specific antibodies were detected in sham-inoculated or uninoculated control piglets. These studies demonstrate that the lesions of PMWS can be experimentally reproduced in gnotobiotic piglets using filterable viral agents derived from pigs with PMWS and provide an experimental basis for further investigation into the pathogenesis and control of this emerging infectious disease in swine.

Cutaneous neosporosis in a dog in Israel

Cutaneous neosporosis manifested by pyogranulomatous ulcerative dermatitis was diagnosed in an 11-year-old male Boxer. Histology revealed numerous intralesional protozoal tachysoites within macrophages and neutrophils. Occasionally, tachysoites were observed within endothelial and epithelial cells. Infection with Neospora caninum was confirmed by avidin biotin complex immunohistochemistry using a Neospora-specific monoclonal antibody. Cutaneous neosporosis is rare and has only been previously described in three cases. This report represents the first case of canine neosporosis in Israel and the Middle East.

Peripheral T-cell activation in non-segmental vitiligo

Vitiligo is a hypopigmentary dermatosis of probable autoimmune origin. Previously reported aberrations in peripheral blood mononuclear cells (PBMC), especially T cells and T cell subsets, have been inconsistent. Lymphocyte subpopulations were examined using flow cytometry and monoclonal antibodies against CD4, CD8, CD20, CD25, CD45RA, and HLA-DR in 34 patients with non-segmental vitiligo. Twelve patients had not received any previous treatment and 22 had previously received at least one course of PUVA therapy that was discontinued at least four months prior to our study. Compared to matched controls, we found significant increases in CD25 and HLA-DR in vitiligo patients (p = 0.000). An inverse correlation was observed between HLA-DR and patient status with regard to treatment (p = 0.001). These results suggest a role for T cells in the pathogenesis of vitiligo and imply that previous PUVA therapy may be reflected by an alteration in circulating DR +ve cells.

Isolation of circovirus from lesions of pigs with postweaning multisystemic wasting syndrome

Postweaning multisystemic wasting syndrome (PMWS), an apparently new disease, has been recognized in swine herds in western Canada. Young pigs with this disease have progressive weight loss, tachypnea, dyspnea, and jaundice, accompanied by interstitial pneumonia, lymphadenopathy, hepatitis, and nephritis. We examined more than 400 pigs from more than 70 herds in Alberta, Saskatchewan, and Manitoba with cases of PMWS. A small virus was isolated from a range of tissues from 8 of 8 affected pigs examined. The agent was identified as a circovirus-like virus using electron microscopy, immunohistochemical staining with porcine and rabbit immune serum, and in situ hybridization. Immunohistochemical examination of tissues from more than 100 affected pigs has revealed widespread viral antigen, often contained in circovirus-like inclusion bodies, in lesions from numerous organs. Although Koch's postulates remain to be fulfilled, these results demonstrate a high degree of association between the presence of the circovirus-like virus and PMWS in affected swine.

An outbreak of vampire bat-transmitted rabies in cattle in northeastern Mexico

An outbreak of bovine rabies occurred on a ranch when cattle were bitten by vampire bats. Microscopic lesions showed a nonsuppurative encephalitis with intracytoplasmic inclusion bodies. Immunohistochemistry demonstrated viral antigen in the brain, and monoclonal antibodies identified a serotype 1 (vampire strain) of the rabies virus.

Tracking H-2 alleles in transgenic mice by RFLP and heteroduplex analysis

Transgenic mice provide valuable tools for biological research including many areas of immunology. In studies involving the major histocompatibility complex (MHC), it is often necessary to place the desired transgene in a specific H-2 (the murine MHC) environment. In this regard, the strains commonly used for the production of transgenic mice also carry well characterized H-2 alleles and provide an appropriate genetic background for MHC related experiments. In this study, a highly polymorphic microsatellite of tetranucleotide repeats from the second intron of the class II Eb gene within the H-2 complex was used in order to identify the corresponding alleles. The relevant H-2 allele(s) along with the transgene were then tracked throughout the production of a chicken ovalbumin-specific transgenic strain. The technique involved PCR-amplification of a DNA sequence encompassing the H-2 specific microsatellite followed by RFLP and heteroduplex analyses. This approach is likely to find wide application in the background checking of transgenic mice, especially in immunological research requiring a defined H-2 background.

Lymphangiosarcoma in a young dog

Lymphangiosarcoma was diagnosed from biopsy material obtained from an 8-week-old puppy with a progressively enlarging subcutaneous inguinal swelling. Histologically, the tumor was composed of endothelial cells immediately adjacent to large collagen bundles. Tumor cells formed irregular vascular channels which extended along the connective tissue investments of small vessels and nerves of the subcutis and deep dermis. Similar neoplastic tissue extensively infiltrated an inguinal lymph node. Neoplastic cells were immunohistochemically stained for factor 8-related antigen and were weakly positive when compared with several hemangiomas and hemangiosarcomas. Transmission electron microscopy revealed numerous micropinocytotic vesicles and a continuous basal lamina. The puppy was euthanatized at 8 months of age due to severe septic polyarthritis. Lymphangiosarcoma was documented at the site of the original tumor as well as in the axillary lymph node at necropsy.

Focal myasthenia gravis as a paraneoplastic syndrome of canine thymoma: improvement following thymectomy

A 10-year-old, neutered male cocker spaniel-cross experienced regurgitation, dry retching, and weight loss. A large, mediastinal mass and dilatation of the esophagus were seen on thoracic radiographs. Cytological, histopathological, immunohistochemical, and serological findings were consistent with a lymphoepithelial thymoma and focal, esophageal myasthenia gravis. Surgical removal of the mass resulted in rapid resolution of the megaesophagus and a decrease in serum acetylcholine-receptor antibody concentration. The dog was clinically normal until the thymoma recurred six months postoperatively. Clinical signs, diagnostic evaluation, management, and treatment of a dog with thymoma and megaesophagus are described.

Fatal pneumonia in adult dairy cattle associated with active infection with bovine respiratory syncytial virus

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Intelligent Medical Record--entry (IMR-E)

This paper describes an automated medical record designed to allow providers to enter patient data at the point of care. The system runs on PCs and Macintoshes and uses a graphical user interface and object-oriented programming to take advantage of current mouse and pen technologies. The provider acquires all relevant patient data by pointing and clicking at selections on input screens, many of which contain anatomical drawings to help the provider quickly and accurately describe patient findings. The system also generates a grammatically correct progress note using the problem-oriented structure. Furthermore, items identified in the assessment and plans portion of the program can be ported to expert systems for medical decisions assistance or to billing systems. The system allows the provider to obtain the necessary information on a focused patient visit in less than 5 min or to enter a complete history and physical.

Expression of HERV-K proviruses in human leukocytes

HERV-K is a 50-copy, human endogenous, class 1 retroviral element that contains some polycistrons with gag, pol, and env open reading frames. Although expression of HERV-K proviruses has been shown in cultured human cell lines, expression of these elements has not been shown in human blood leukocytes. Using both reverse transcriptase-polymerase chain reaction and ribonuclease protection techniques, we show HERV-K pol gene expression in human blood leukocytes. Expression in blood leukocytes from 7 normal individuals was from a variety of different HERV-K proviruses, while restricted expression was observed in blood cells of 5 leukemia patients and 3 polycythemia vera patients. Evidence is presented suggesting that the restricted expression in leukemia blood cells is a result of gene regulation, not gene amplification.