Psoriasis confined strictly to vitiligo areas – a Koebner‐like phenomenon?

Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.     

Studies on the origin of redox enzymes in seminal plasma and their relationship with results of in-vitro fertilization

Glutathione (GSH), GSH peroxidase (GPX), GSH reductase (GRD), superoxide dismutase (SOD) and catalase-like enzyme activity were quantified in seminal plasma from normozoospermic patients, men with known distal ductal occlusion, proven fathers and male partners of couples receiving in-vitro fertilization (IVF) treatment for both male and female causes. Glutathione was non-detectable (< 2.5 microM) in seminal plasma. None of the enzyme activities per unit volume were lower in semen from vasectomized men, suggesting that they did not originate substantially from the testis or epididymis. The strongest relationships between enzyme activities and accessory gland markers were between zinc and GRD (r = 0.678), SOD (r = 0.602) and GPX (r = 0.548), suggesting a largely prostatic origin of these enzymes. Only weak relationships between accessory gland markers and catalase-like activity suggested a multi-glandular source of this enzyme. There was no relationship between the activity of any of the enzymes in the IVF patients with their fertilization rates in vitro or the establishment of pregnancy after IVF. Nor was there any correlation of enzyme activity with the morphology and percentage of motile spermatozoa in semen or with the percentage motility of spermatozoa immediately after swim-up or after overnight incubation. These findings suggest that the protective enzymes in the seminal plasma are contributed largely by the prostate and little by the epididymis, and that in most cases of IVF, they have no major influence on the outcome.      

Rabies virus binding at neuromuscular junctions

Morphological, immunocytochemical, biochemical, and immunological techniques have been used to describe rabies virus binding to a sub-cellular unit and molecular complex at the neuromuscular junction (NMJ). Early after infection in vivo, virus antigen and virus particles were found by immunofluorescence, electron microscopy and immunoelectron microscopy in regions of high density acetylcholine receptors (AChR) at NMJs. One monoclonal antibody (alpha-Mab) to the alpha subunit of the AChR blocked attachment of radio-labeled rabies virus to cultured muscle cells bearing high density patches of AChR. A sub-cellular structure, resembling an array of AChR monomers, bound both rabies virus antigens and alpha-Mab. By immunoblotting with electrophoretically transferred motor endplate proteins, rabies virus proteins and alpha-Mab bound to two proteins of 43 000 and 110 000 daltons. A rabies virus glycoprotein antibody detected virus antigen bound to the 110 000 dalton protein. An auto-immune (anti-idiotypic) response followed immunization of mice with rabies virus glycoprotein antigen; the antibody was directed to the 110 000 dalton protein. This auto-antibody altered the kinetics of neutralization by rabies virus antibody and induced the formation of rabies virus antibody after inoculation of mice. These results define, at the neuromuscular junction, a rabies virus receptor which may be part of the acetylcholine receptor complex.     

Neutralizing antibodies to African swine fever virus proteins p30, p54, and p72 are not sufficient for antibody-mediated protection

Although antibody-mediated immune mechanisms have been shown to be important in immunity to ASF, it remains unclear what role virus neutralizing antibodies play in the protective response. Virus neutralizing epitopes have been identified on three viral proteins, p30, p54, and p72. To evaluate the role(s) of these proteins in protective immunity, pigs were immunized with baculovirus-expressed p30, p54, p72, and p22 from the pathogenic African swine fever virus (ASFV) isolate Pr4. ASFV specific neutralizing antibodies were detected in test group animals. Following immunization, animals were challenged with 10(4) TCID(50) of Pr4 virus. In comparison to the control group, test group animals exhibited a 2-day delay to onset of clinical disease and reduced viremia levels at 2 days postinfection (DPI); however, by 4 DPI, there was no significant difference between the two groups and all animals in both groups died between 7 and 10 DPI. These results indicate that neutralizing antibodies to these ASFV proteins are not sufficient for antibody-mediated protection.     

Lung tumor-associated derepressed alloantigen coded for by the K region of the H-2 major histocompatibility complex

Transplacental induction of lung tumors in C3HfeB/HeN (C3Hf) strain mice can be readily achieved with the carcinogen 1-ethyl-1-nitrosourea. Several of these tumors express, as a tumor-associated transplantation antigen (TATA), a normal tissue alloantigen present in strain A and C3H/HeN (C3H) mice. In the present study it was shown that the tumor-associated alloantigen on the C3Hf-derived lung tumor 85 was present in all mice of H-2(a) and H-2(k) haplotypes tested and in CBA (532) strain mice (H-2(ka) haplotype). Studies using congenic-resistant and recombinant strains of mice indicated that the genetic locus controlling the expression of this antigen was either within or to the left of the H-2K region of the major histocompatibility complex (MHC). Thus the antigen was expressed in B10.A (4R) mice (kkbbbb MHC haplotype) but not in B10 (bbbbbb) or B10.AQR mice (qkkddd). The antigen was expressed in all tissues tested of C3H and A strain mice. It was not detected on any tissue tested including embryo tissue of C3Hf mice or mice of MHC haplotype other than H-2(k) or H-2(a). Because C3Hf strain mice were originally derived from C3H strain mice (H-2(k)), the MHC haplotype of C3Hf mice has been provisionally designated H-2(kb). The finding of a tumor-associated change in the expression of a H-2K region-coded antigen is consistent with the concept that MHC-coded antigens may act as targets for immunological surveillance of tumors.     

Delayed activation of quiescent donor hematopoietic stem cells in the host marrow cavity by anti-host monoclonal antibody

To understand the mechanisms controlling hematopoietic engraftment in untreated, normal recipients, we investigated the fate of parental, donor hematopoietic stem cells after apparent graft failures in unconditioned F1 hybrid recipient mice. By administering an anti-host H- 2K monoclonal antibody, which targets host cells but spares the donor, we found that chimerism could be induced by delayed conditioning in animals with apparent graft failure. Engraftment kinetics in the host were followed by typing individual colony forming unit-- granulocyte/macrophage (CFU-GM) colonies for their origin and showed that parental cells, which were otherwise virtually absent, become promptly detectable within the marrow cavity after antibody administration. Marrow transfers to secondary hosts suggested that parental stem cells were present in the marrow of the untreated recipients. These findings establish that the elimination of all parental cells cannot account for the absence of peripheral blood chimerism in the unconditioned F1 hybrid recipient. Thus, viable and functional donor stem cells, which remain quiescent in the host marrow, can be activated by a selective conditioning regimen and can rescue an apparent graft failure. The selective activation in vivo of marked stem cells in an unirradiated microenvironment may be a useful system to study the regulation of cellular proliferation within the marrow cavity.     

Circannual variation in lymphocyte subsets, revisited

BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply.     

Ophthalmic manifestations in the COVID-19 clinical spectrum

Purpose:The aim of this study was to determine the frequency and various types of ophthalmic manifestation of patients with COVID-19.Methods:This is a prospective observational study conducted on patients with SARS-Co-V-2 infection, at a dedicated tertiary COVID-19 hospital in South India from April 1 to July 31, 2020. At the time of their admission to the COVID hospital, demographic data such as name, age, sex was recorded. A thorough history regarding the onset, duration, progression, nature of symptoms and its associated factors, medication history, treatment history were elicited and documented. Ocular examination was performed under torchlight by an ophthalmologist posted for COVID duty. Further investigations including imaging were sought for, depending on clinical indications. Serial follow-up examinations of all patients were carried out every 72 hours or when patients complained of any ocular symptoms whichever earlier, until discharge. All relevant data were compiled and statistically analyzed.Results:A total of 2742 patients were examined. Of them, 1461 (53.28%) were males and 1281 (46.72%) were females. The mean age (±SD) was 39.46 ± 17.63 years. None of the patients in our study had any ocular symptoms or signs as the presenting complaint at the time of their admission. On subsequent follow-up, only 20 (0.72%) developed ocular manifestations, of which 19 (95%) had features suggestive of Bilateral viral conjunctivitis. However, 1 (5%) patient had orbital cellulitis secondary to pansinusitis.Conclusion:Ophthalmic manifestations in the clinical spectrum of COVID-19 infection are uncommon and unlikely to be the presenting clinical impression. However, it has broadened our view to a wider spectrum of COVID-19 presentations enhancing our clinical acumen for staunch detection of COVID-19 suspects in our daily practice, augmenting early diagnosis and management and also break the chain of transmission for the greater good of humanity.