Hematopoietic turnover index in reactive and neoplastic bone marrow lesions: quantification by apoptosis and PCNA labeling

 In order to determine the dynamics of hematopoietic cell turnover, proliferative activity and incidence of apoptosis (programmed cell death) were evaluated in bone marrow trephine biopsies. Selection of patients (20 in each group) included in addition to a control group, idiopathic thrombocytopenia (ITP), reactive thrombocytosis (TH), secondary polycythemia-smokers' polyglobuly (PG), primary (essential-hemorrhagic) thrombocythemia (PTH), polycythemia vera (PV), and finally acute myeloid leukemia (AML). Apoptosis was demonstrated by the in situ end-labeling technique (ISEL) and proliferative activity by applying the monoclonal antibody PC10 raised against proliferating cell nuclear antigen (PCNA). To assess dynamic features of hematopoiesis, an index was calculated consisting of the ratio between PCNA-positive nuclei and the apoptotic cell fraction. This factor was termed the hematopoietic turnover index (HTI). Morphometric analysis revealed that the HTI was significantly increased in AML and PV. According to cell culture studies both disorders are characterized by either a prevalent proliferation of the myeloid or erythroid cell mass. On the other hand, PG, PTH, and TH showed no relevant enhancement of this index in comparison to the control specimen. In vitro experiment results are in keeping with the finding that PG and PTH are not associated with a significant expansion of the erythroid lineage (CFU-E). Similar to ITP and TH, in PTH megakaryocyte proliferation (CFU-MEG) is the predominant feature of cell turnover. Differences between PTH and TH are in line with the reduced in vitro formation of CFU-MEG in the latter disorder. In conclusion, our in situ study on turnover rates of the bone marrow in various neoplastic and reactive lesions extends previous experimental data on hematopoietic cell kinetics. Received: 10 March 1997 / Accepted: 18 May 1997     

Glucocorticoid and starvation effect on glycosaminoglycans in vascular connective tissue. Biochemical studies on repair processes in rabbit aorta.

Male rabbits were injured by a single mechanical dilatation injury of aorta and then injected with prednisone 2 mg/kg or saline for 14 days or subjected to starvation. The biosynthesis of the sulfated glycosaminoglycans as evaluated by the uptake of 35S-sulfate and the content of the glycosaminoglycans were measured on the intima-media layer of the descending thoracic aorta. The results indicate that prednisone may inhibit the biosynthesis of heparan and/or dermatan sulfate while starvation increases the biosynthesis of all the sulfated glycosaminoglycans. No alterations were observed in the total amount of glycosaminoglycans in aorta following glucocorticoid injection or starvation. The metabolism of aortic glycosaminoglycans during repair is less sensitive to the action of prednisone than in undamaged aorta. This contrasts with the effect of prednisone on the metabolism of aortic collagen.     

Immunity induced shortly after DNA vaccination of rainbow trout against rhabdoviruses protects against heterologous virus but not against bacterial pathogens.

It was recently reported that DNA vaccination of rainbow trout fingerlings against viral hemorrhagic septicaemia virus (VHSV) induced protection within 8 days after intramuscular injection of plasmid DNA. In order to analyse the specificity of this early immunity, fish were vaccinated with plasmid DNA encoding the VHSV or the infectious haematopoietic necrosis virus (IHNV) glycoprotein genes and later challenged with homologous or heterologous pathogens. Challenge experiments revealed that immunity established shortly after vaccination was cross-protective between the two viral pathogens whereas no increased survival was found upon challenge with bacterial pathogens. Within two months after vaccination, the cross-protection disappeared while the specific immunity to homologous virus remained high. The early immunity induced by the DNA vaccines thus appeared to involve short-lived non-specific anti-viral defence mechanisms.     

High-resolution tensor MR elastography for breast tumour detection

MR elastography is a novel imaging technique for the visualization of elastic properties of tissue. It is expected that this method will have diagnostic value for the clarification of suspicious breast lesions. Low-frequency mechanical waves are coupled into the tissue and visualized via an MR sequence which is phase-locked to the mechanical excitation. Commonly, elasticity is assumed to be isotropic and reconstruction is performed in only two dimensions. The technique is extended to three dimensions such that the entire symmetric elasticity tensor is assessed. This is achieved by measuring different phases of the mechanical wave during one oscillatory cycle. Thereby it is possible to provide information about the anisotropy of the elasticity tensor. Finite-element simulations as well as phantom experiments are performed to demonstrate the feasibility of the method. Initial clinical results of a breast carcinoma are presented. The analysis of the eigenvalues of the elasticity tensor support the hypothesis that breast carcinoma might exhibit an anisotropic elasticity distribution. The surrounding benign tissue appears isotropic. Thereby new and additional diagnostic information is provided which might help in distinguishing between benign and malignant breast diseases.     

Enhanced cellular immune response and reduced CD8(+) lymphocyte apoptosis in acutely SIV-infected Rhesus macaques after short-term antiretroviral treatment

Losing the decisive virus-specific functions of both CD4(+) and CD8(+) T lymphocytes in the first weeks after immunodeficiency virus infection ultimately leads to AIDS. The SIV/rhesus monkey model for AIDS was used to demonstrate that a 4-week chemotherapeutic reduction of viral load during acute SIV infection of macaques allowed the development of a competent immune response able to control virus replication after discontinuation of treatment in two of five monkeys. Increasing SIV-specific CD4(+) T-helper-cell proliferation was found in all macaques several weeks after treatment, independent of their viral load. However, only macaques with low viral loads showed persistent T-cell reactivity of lymph node cells. In contrast to animals with higher viral loads, T-helper-cell counts and memory T-helper cells did not decline in the two macaques controlling viral replication. Lymphocyte apoptosis was consistently low in all treated macaques. In contrast, high CD8(+) lymphocyte death but only slightly increased CD4(+) lymphocyte apoptosis were observed during the first weeks after infection in untreated control animals, indicating that early apoptotic death of virus-specific CTL could be an important factor for disease development. Antiretroviral treatment early after infection obviously retained virus-specific and competent T lymphocytes, whereby a virus-specific immune response could develop in two animals able to control the viral replication after cessation of treatment.     

Principal cells of the rat medial nucleus of the trapezoid body: an intracellular in vivo study of their physiology and morphology

The medial nucleus of the trapezoid body (MNTB) is one of several principal nuclei in the superior olivary complex (SOC) of mammals. It is classically thought to function as a relay station between the contralateral ventral cochlear nucleus and the lateral superior olive (LSO), playing a role among those brainstem nuclei that are involved in binaural hearing. In order to characterise the physiology and morphology at the cellular level of the major neuronal component of the MNTB, the principal cells, we have analysed these neurons in rats in vivo using intracellular recordings and horseradish peroxidase-labelling. Our data demonstrate that MNTB principal cells, when being stimulated acoustically via the contralateral ear, show a phasic-tonic response with an onset latency of 3.5 ms and a suppression of their spontaneous activity following stimulus offset. These neurons have an axonal morphology whose complexity has not yet been described. All cells (n=10) projected exclusively ipsilaterally and had terminal axonal arbors in a variety of auditory brainstem nuclei. At least two and maximally seven auditory targets were innervated by an individual cell. Each cell projected into the LSO and the superior paraolivary nucleus (SPN). Additional projections that were intrinsic to the SOC were often observed in the lateral nucleus of the trapezoid body and in periolivary regions, with only one cell projecting into the medial superior olive. Most, if not all, MNTB principal cells also had projections that were extrinsic to the SOC, as their axons ascended into the lateral lemniscus. In two neurons the ascending axon formed terminal arbors in the ventral nucleus of the lateral lemniscus, and the dorsal nucleus of the lateral lemniscus could be identified as a target of one neuron. The location of the cell bodies of the MNTB principal cells correlated with the neurons' best frequencies, thereby demonstrating a tonotopic organisation of the MNTB, with high frequencies being represented medially and low frequencies laterally. The axonal projections into the LSO and the SPN were also tonotopically organised and the alignment of the tonotopic axes was similar to that in the MNTB. Our results confirm previous data from other species and suggest that MNTB principal cells have a great amount of physiological and morphological similarities across mammalian species. Furthermore, the complexity of the axonal projections indicates that these neurons play a role in auditory information processing which goes far beyond their previously described classical role.     

Hypercalcemia After Cosmetic Oil Injections: Unraveling Etiology,Pathogenesis, and Severity

Intramuscular injections of paraffin oil can cause foreign body granuloma formation and hypercalcemia. Macrophages with the ability to produce high levels of 1,25(OH)₂D₃ may induce the mineral disturbance, but no major series of patients have been published to date. Here, medical history, physical evaluation, biochemical, and urinary analysis for calcium homeostasis were obtained from 88 males, who 6 years previously had injected paraffin or synthol oil into skeletal muscle. Moreover, granuloma tissue from three men was cultured for 48 hours ex vivo to determine 1,25(OH)₂D₃ production supported by qPCR and immunohistochemistry of vitamin D metabolism and immune cell populations after treatment with 14 different drugs. The 88 men were stratified into men with hypercalcemia (34%), whereas normocalcemic men were separated into men with either normal (42%) or suppressed parathyroid hormone (PTH) (24%). All men had high calcium excretion, and nephrolithiasis was found in 48% of hypercalcemic men, 22% of normocalcemic men with normal PTH, and 47% of normocalcemic men with suppressed PTH. Risk factors for developing hypercalcemia were oil volume injected, injection of heated oil, high serum interleukin-2 receptor levels, and high urine calcium. High 1,25(OH)₂D₃/25OHD ratio, calcium excretion, and low PTH was associated with nephrolithiasis. The vitamin D activating enzyme CYP27B1 was markedly expressed in granuloma tissue, and 1,25(OH)₂D₃ was released in concentrations corresponding to 40% to 50% of the production by human kidney specimens. Dexamethasone, ketoconazole, and ciclosporin significantly suppressed granulomatous production of 1,25(OH)₂D₃. In conclusion, this study shows that injection of large oil volumes alters calcium homeostasis and increases the risk of nephrolithiasis. Hypercalciuria is an early sign of disease, and high granulomatous 1,25(OH)₂D₃ production is part of the cause. Prospective clinical trials are needed to determine if ciclosporin, ketoconazole, or other drugs can be used as prednisolone-sparing treatment. © 2020 American Society for Bone and Mineral Research (ASBMR).