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.

Detection of equine herpesvirus and differentiation of equine herpesvirus type 1 from type 4 by the polymerase chain reaction

Although both equine herpesvirus type 1 (EHV-1) and equine herpesvirus type 4 (EHV-4) can be associated with respiratory disease, epizootics caused by EHV-1 are much more serious because the virus can cause abortions and paralysis. It is, therefore, important to identify the type of EHV involved in an outbreak by a test that is quick, sensitive, and reliable. We have adapted the polymerase chain reaction (PCR) to detect and distinguish between EHV-1 and EHV-4 in the same reaction. Primers for PCR were designed from the sequences of the glycoprotein B genes of EHV-1 and EHV-4. The PCR products derived from EHV-1 and EHV-4 were 135 and 326 base pairs, respectively, and could be readily separated by electrophoresis. The identity of the PCR products was confirmed by determining their nucleotide sequence, which agreed with the published sequence of the gB genes. The test could be performed directly on virus pelleted from small volumes (300 microL) of medium in which nasal swabs were transported and did not rely on the presence of infectious virus. The PCR was unaffected by conditions that reduced the infectivity of a virus preparation by 99%. The PCR detected EHV-4 in 5 of 10 nasal mucous samples taken from an outbreak of respiratory disease in race horses. Virus isolation in indicator cells was successful in detecting virus in four of the five samples positive by PCR.

Lysate RNase protection method for soft tissues

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