The Effect of Surrounding Vegetation on the Mycorrhizal Fungal Communities of the Temperate Tree Crataegus monogyna Jacq

About 90% of all land plants form mycorrhiza to facilitate the acquisition of essential nutrients such as phosphorus, nitrogen, and sometimes carbon. Based on the morphology of the interaction and the identity of the interacting plants and fungi, four major mycorrhizal types have been distinguished: arbuscular mycorrhiza (AM), ectomycorrhizal (EcM), ericoid mycorrhiza, and orchid mycorrhiza. Although most plants are assumed to form only one type of mycorrhiza, some species simultaneously form associations with two mycorrhizal types within a single root system. However, the dual-mycorrhizal status of many species is under discussion and in some plant species the simultaneous association with two mycorrhizal types varies in space or time or depends on the ecological context. Here, we assessed the mycorrhizal communities associating with common hawthorn (Crataegus monogyna), a small tree that commonly associates with AM fungi, and investigated the potential factors that underlie variation in mycorrhizal community composition. Histological staining of C. monogyna roots showed the presence of a Hartig net and hyphal sheaths in and around the roots, demonstrating the capacity of C. monogyna to form EcM. Meta-barcoding of soil and root samples of C. monogyna collected in AM-dominated grassland vegetation and in mixed AM + EcM forest vegetation showed a much higher number of EcM sequences and OTUs in root and soil samples from mixed AM + EcM vegetation than in samples from pure AM vegetation. We conclude that C. monogyna is able to form both AM and EcM, but that the extent to which it does depends on the environmental context, i.e., the mycorrhizal type of the surrounding vegetation.

Enlightening the black and white: species delimitation and UNITE species hypothesis testing in the Russula albonigra species complex

Russula albonigra is considered a well-known species, morphologically delimited by the context of the basidiomata blackening without intermediate reddening, and the menthol-cooling taste of the lamellae. It is supposed to have a broad ecological range and a large distribution area. A thorough molecular analysis based on four nuclear markers (ITS, LSU, RPB2 and TEF1-α) shows this traditional concept of R. albonigra s. lat. represents a species complex consisting of at least five European, three North American, and one Chinese species. Morphological study shows traditional characters used to delimit R. albonigra are not always reliable. Therefore, a new delimitation of the R. albonigra complex is proposed and a key to the described European species of R. subgen. Compactae is presented. A lectotype and an epitype are designated for R. albonigra and three new European species are described: R. ambusta, R. nigrifacta, and R. ustulata. Different thresholds of UNITE species hypotheses were tested against the taxonomic data. The distance threshold of 0.5% gives a perfect match to the phylogenetically defined species within the R. albonigra complex. Publicly available sequence data can contribute to species delimitation and increase our knowledge on ecology and distribution, but the pitfalls are short and low quality sequences.

Looks can be deceiving: the deceptive milkcaps (Lactifluus, Russulaceae) exhibit low morphological variance but harbour high genetic diversity

The ectomycorrhizal genus Lactifluus is known to contain many species complexes, consisting of morphologically very similar species, which can be considered cryptic or pseudocryptic. In this paper, a thorough molecular study is performed of the clade around Lactifluus deceptivus (originally described by Peck from North America) or the deceptive milkcaps. Even though most collections were identified as L. deceptivus, the clade is shown to contain at least 15 species, distributed across Asia and America, indicating that the L. deceptivus clade represents a species complex. These species are morphologically very similar and are characterized by a tomentose pileus with thin-walled hyphae and a velvety stipe with thick-walled hyphae. An ITS1 sequence was obtained through Illumina sequencing for the lectotype of L. deceptivus, dating from 1885, revealing which clade represents the true L. deceptivus. In addition, it is shown that three other described species also belong to the L. deceptivus clade: L. arcuatus, L. caeruleitinctus and L. mordax, and molecularly confirmed that L. tomentoso-marginatus represents a synonym of L. deceptivus. Furthermore, two new Neotropical species are described: Lactifluus hallingii and L. domingensis.

Lactifluusbicapillus (Russulales, Russulaceae), a new species from the Guineo-Congolian rainforest

The milkcap genus Lactifluus is one of the most common ectomycorrhizal genera within Central African rainforests. During a field trip to the Dja Biosphere Reserve in Cameroon, a new Lactifluus species was found. Molecular and morphological analyses indicate that the species belongs to LactifluussectionXerampelini and we formally describe it here as Lactifluusbicapillussp. nov.

A Study of a Caucasian Family with Variant von Willebrand’s Disease in Association with Vascular Telangiectasia and Haemoglobinopathy

A family was identified which carries multi-haematological disorders including Type IIA von Willebrand’s disease, vascular telangiectasia, and a haemoglobinopathy (haemoglobin S trait). In the affected individuals, the von Willebrand’s disease varies in its expression from an asymptomatic form to a severe form especially in those patients with telangiectasia. Some patients have vascular telangiectasia in the mucous membranes of the mouth and lips. In two patients endoscopy disclosed telangiectasia in the mucous membranes of the gastrointestinal tract. All of the patients who had telangiectasia also had von Willebrand’s disease. An incidental finding was the presence of an abnormal haemoglobin (haemoglobin S) in some family members. The pattern of inheritance of the haemoglobinopathy was unrelated to the inheritance pattern of von Willebrand’s disease. The presence of haemoglobin S did not interfere with the aggregation of platelets in response to ristocetin.

Considerations and consequences of allowing DNA sequence data as types of fungal taxa

Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.

Effects of spaceflight on rat peripheral blood leukocytes and bone marrow progenitor cells

The white blood cell (WBC) elements and the bone marrow myeloid progenitor cell populations were analyzed to ascertain adaptation to micro-gravity and subsequent readaptation to 1 G in rats flown on the 14-day Spacelab Life Sciences-2 (SLS-2) mission. Bone marrow cells were harvested from one group of rats killed inflight (FD13) and blood was drawn from three other groups at various times. The WBC level was normal on FD14 with the exception of neutrophilia. On FD13, numbers of colony-forming units-granulocyte (CFU-G), CFU-GM, and CFU-M from flight animals were decreased compared with ground controls when incubated with recombinant rat interleukin-3 (rrIL-3) alone or in combination with recombinant human erythropoietin (rhEpo). On recovery (R + 0), flight rats had decreased numbers of total leukocytes and absolute numbers of lymphocytes and monocytes with elevated neutrophils compared with control rats. They had lower numbers of CD4, CD8, CD2, CD3, and B cells in the peripheral blood but no differences in spleen lymphocytes.

Effects of spaceflight on rat erythroid parameters

Hematologic studies were performed on 21 ground control rats and 21 rats flown during the Spacelab Life Sciences-2 14-day mission. Group A (n = 5) was used to collect blood in flight and 9 days postflight, group B (n = 5) was injected with recombinant human erythropoietin (rhEpo), group C (n = 5) received saline as a control, and group D (n = 6) was killed in flight and tissues were collected. Results indicated no significant changes in peripheral blood erythroid elements between flight and ground control rats. The nonadherent bone marrow on flight day 13 showed a lower number of recombinant rat interleukin-3 (rrIL-3)-responsive and rrIL-3 + rhEpo-responsive blast-forming unit erythroid (BFU-e) colonies in flight rats compared with ground control rats. On landing day, a slight increase in the number of rhEpo + rrIL-3-responsive BFU-e colonies of flight animals compared with ground control rats was evident. Nine days postflight, bone marrow from flight rats stimulated with rhEpo alone or with rhEpo + rrIL-3 showed an increase in the number of colony-forming unit erythroid colonies and a decrease in BFU-e colonies compared with ground control rats. This is the first time that animals were injected with rhEpo and subsequently blood and tissues were collected during the spaceflight to study the regulation of erythropoiesis in microgravity.

Lymphatic tissue changes in rats flown on Spacelab Life Sciences-2

Thymus, spleen, inguinal lymph node, and bone marrow specimens from rats flown on the 14-day Spacelab Life Sciences-2 mission were examined after staining of tissue sections. The primary observation was a transient retrogressive change in lymphatic tissues in the rats within a few hours after landing. There was a diffuse increase in tingible body-containing macrophages in the cortex of the thymus, thymus-dependent areas of the splenic white pulp, and inguinal lymph node. This was not observed 9 days after recovery. The in situ labeling of fragmented DNA strands catalyzed by exogenous terminal deoxynucleotidyltransferase (TdT) with ApopTag reagents (Oncor, Gaithersburg, MD) inside the tingible body-containing macrophages indicated that the process was one of apoptosis. No increase in tingible body macrophage activity was noted in thymus and spleen tissue obtained from rats in flight on flight day 13. The reaction to gravitational stress from readaptation to 1 G is the most likely explanation of the transient retrogressive change in lymphatic tissues.

Blood volume and erythropoiesis in the rat during spaceflight

A decreased red blood cell mass (RBCM) and plasma volume (PV) have been consistently found in humans after return from spaceflight. Rats flown on the Spacelab Life Sciences-1 mission were studied to assess changes in RBCM, PV, erythropoiesis, and iron economy. The RBCM and PV increased in both ground control and flight animals as expected for growing rats. However on landing day, both the RBCM and PV, when normalized for body mass, were significantly decreased in the spaceflight animals. During an 8-d postflight observation period, iron incorporation into circulating red blood cells was diminished in the flight animals. During the first 4 d postflight, increases in reticulocyte counts were significantly smaller in the flight than the control animals. Fewer erythropoietin-responsive progenitor cells were recovered from the bone marrow of flight animals after landing than control rats. Serum erythropoietin (EPO) levels were the same in both groups. Thus, rats subjected to a 9-d spaceflight had less increase in RBCM than controls and diminished erythropoiesis during an 8-d post-spaceflight observation period. The rat, like humans, appears to require a smaller blood volume in microgravity.

Effects of microgravity and increased gravity on bone marrow of rats

Astronauts have a reduction in their red cell mass when exposed to microgravity. This is probably mainly due to a physiological response to decreased energy requirements. Further studies of erythropoiesis were carried out in microgravity on rats flown on Soviet Biosatellite 2044 and in hypergravity by centrifugation at 2G. Studies included: bone marrow cell differential counts, clonal studies of RBC colony formation, and plasma erythropoietin determinations. In the bone marrow of Cosmos flight animals there was a slight increase in granulocytic cells and in centrifuged animals, a slight decrease in the percentage of erythroid cells which led to an increased M:E ratio. The bone marrow cells of flight and centrifuged rats responded to erythropoietin. Cosmos flight animals' cells formed fewer CFU-E than the controls but this was reversed in the centrifuge studies. There were no essential differences in the erythropoietin levels of test groups as compared to control groups.

Effects of spaceflight on the number of rat peripheral blood leukocytes and lymphocyte subsets

Experiments were carried out on peripheral blood leukocytes and spleen lymphocytes from 29 male rats that were flown during the Spacelab Life Sciences 1 (SLS-1) nine-day mission on the shuttle Columbia in June 1991 and on appropriate ground controls. On the day of landing, there was a significant decrease in the total white blood cell counts (P < 0.0001) of flight animals in comparison to controls. There was also a significant decrease in the absolute number of lymphocytes (P < 0.0001) and monocytes (P < 0.0001) in the flight animals. A slight decrease in the absolute number of eosinophils and a slight increase in the number of neutrophils were observed at landing, compared with preflight values. Immunophenotyping of the peripheral blood and spleen lymphocytes of flight and control animals indicated that, on the day of landing, there was a decrease in the absolute number of CD4 and CD8 positive cells and B lymphocytes. However, relative percentages of peripheral blood CD4+, CD8+, and B cells were not found to be depressed. No differences were discerned in the percent reactivity of spleen lymphocytes of flight animals compared with controls. The observed decrease in the number of leukocytes and lymphocytes at the immediate postflight period was transient and all values returned to the control levels by nine days postflight.

Synchrony of bone marrow proliferation and maturation as the origin of cyclic haemopoiesis

Cyclic haemopoiesis in Grey Collie dogs is characterized by stable oscillations in all haemopoietic lineages. It is proposed that in these animals, in contrast to normal animals, the maturation process of haemopoietic (in particular granuloid) cells from the primitive progenitors to the functional cells is characterized by an abnormally strong synchrony. It is conjectured that the marrow maturation time has a very small variance compared with non-cyclic normal dogs. With a mathematical model of haemopoiesis it is shown that small fluctuations are amplified via regular feedback processes such that stable granuloid oscillations are established. Erythroid oscillations are induced indirectly by granuloid feedback to the stem cell pool. The model calculations further show that the synchrony hypothesis of bone marrow maturation can quantitatively explain the following experimental results: (1) the maintenance of stable cycles of granuloid and erythroid bone marrow and blood cells with a period of approximately 14 d; (2) the disappearance of granuloid and erythroid cycles during the administration of the colony stimulating factor rhG-CSF; (3) the reappearance of oscillations when the administration of CSF is discontinued; (4) the cessation of cycles during endotoxin application; and (5) the persistence of cycles during erythroid manipulations (bleeding anaemia, hypoxia, hypertransfusion). We therefore conclude that cyclic haemopoiesis is not caused by a defect in the regulatory control system but by an unusual maturation process.

Surface morphology and ultrastructure of normal and cyclic hematopoietic canine bone marrow in long-term liquid cultures

Long-term liquid cultures of normal and cyclic hematopoietic (CH) dog bone marrow produce committed granulocyte-macrophage progenitor cells (CFU-GM) and differentiated granulocytes for several weeks. Analysis of in situ fixed cultures or of cells harvested from the culture supernatants revealed that the cells had ultrastructure and surface morphology characteristic of immature and mature myeloid cells. The surface morphologies of adherent cells from both normal and CH dogs were similar. The characteristic abnormalities previously reported in neutrophils obtained from CH dogs were not observed in neutrophils obtained from long-term marrow cultures of CH dogs. These results indicate that the cellular abnormalities in the neutrophils of CH dogs may be secondary manifestations of the disease and are not inherent to the pathogenesis of the hematopoietic cells.

Long-term bone marrow culture systems: normal and cyclic hematopoietic dogs

A continuous long-term liquid culture in both a micro and macro system that incorporates bone marrow cells from normal and cyclic hematopoietic dogs is described. An adherent layer composed of fibroblasts, endothelial cells, mononuclear phagocytic cells, and fat-containing cells is essential for continuous hematopoiesis. Hematopoiesis was measured by the recovery of the nonadherent cells and the generation of committed granulocyte-monocyte progenitor cells for a period of seven weeks. Optimum growth factors include the use of horse serum, fetal bovine serum, dog serum, hydrocortisone, a 33 degrees C incubation temperature and feeding twice a week. As is true for both human and murine marrow liquid cultures, horse serum and hydrocortisone are essential for development and maintenance of fat-containing cells in the described systems. Both factors are important in hematopoiesis but their respective roles have not been defined. Normal and cyclic hematopoietic dogs bone marrow cells are comparable in their ability to establish long-term cultures. The micro-method (Linbro-well culture) gave similar results in maintaining hematopoiesis as did a macromethod (flask culture).

Hematological measurements in rats flown on Spacelab shuttle, SL-3

Previous studies have shown that a decrease in red cell mass occurs in astronauts, and some studies indicate a leukocytosis occurs. A life science module housing young and mature rats was flown on shuttle mission Spacelab 3 (SL-3), and the results of hematology studies of flight and control rats are presented. Statistically significant increases in the hematocrit, red blood cell counts, and hemoglobin determinations, together with a mild neutrophilia and lymphopenia, were found in flight animals. No significant changes were found in bone marrow and spleen cell differentials or erythropoietin determinations. Clonal assays demonstrated an increased erythroid colony formation of flight animal bone marrow cells at erythropoietin doses of 0.02 and 1.0 U/ml but not 0.20 U/ml. These results agree with some but vary from other previously published studies. Erythropoietin assays and clonal studies were performed for the first time.

Regulation of hematopoiesis in rats exposed to antiorthostatic hypokinetic/hypodynamia: II. Mechanisms of the "anemia"

Results are presented which demonstrate a close similarity between the ability of antiorthostatic hypokinetic/hypodynamia and orthostatic hypokinetic/hypodynamia to induce anemia in laboratory rats. The "restraint anemia" (whether mediated directly by reduced activity or indirectly by possible changes in blood circulation or in altered weight-bearing capacity of the skeleton) was largely due to reduced food and/or water consumption and displayed the classical symptoms of inadequate nutrition, i.e. decreased serum erythropoietin (Ep) titers and reduced Ep sensitivity of hematopoietic tissue. Only changes in red blood cell (RBC) clearance were unique to the head-down (antiorthostatic) posture. During suspension, RBC clearance was reduced and then accelerated when suspension was terminated or the cells transfused into a normal environment. Changes in RBC clearance were due to both cell-associated and cell-independent factors and may be related to the alterations in RBC survival seen in rats during or immediately after space flight. In both suspension and weightlessness, these changes were limited to alterations in the force and/or direction of the gravity vector.

Tritiated thymidine incorporation into canine cyclic hematopoietic bone marrow in vitro

To investigate changes in the proliferative activity of bone marrow cells in canine cyclic hematopoiesis, nonadherent cells were incubated for 1 h with tritiated thymidine either immediately after the cultures were established or following an 18-h preincubation period. The data suggest that changes in thymidine incorporation show a 12- to 14-day cycle that consists of two distinct phases. During the first six days of the cycle (from peripheral neutropenia to relative neutrophilia), two peaks of incorporation were observed. During the second phase (corresponding to the neutrophilia and oncoming neutropenia), thymidine incorporation was uniformly lower than control values. The change from an apparently cyclical process to a low stable value occurred after the wave of marrow myelopoiesis and close to a time point (days 8-10 of the cycle) at which we have recently suggested significant changes in cell release and/or proliferation take place. The data can be interpreted in the context of a periphery-to-stem-cell feedback loop through an intermediate cell population, probably of myeloid precursors.

Variant of congenital dyserythropoietic anemia

Nonspherocytic hemolytic anemia was diagnosed in a 34-year-old man with jaundice since childhood. Splenectomy at the age of 8 had no influence on the anemia. Bronze diabetes was diagnosed at age 31, presumably due to hemosiderosis and secondary hemochromatosis. Iron chelation was unsuccessful in controlling iron overload, but phlebotomies proved effective without aggravating the anemia. We believe the anemia represents a variant of congenital dyserythropoietic anemia, type I.

Secretion of ceruloplasmin by a human clear cell carcinoma maintained in nude mice

Ceruloplasmin is the best known but least understood copper protein. Studies preliminary to investigating the control of ceruloplasmin synthesis have utilized a human renal cell carcinoma maintained in nude mice for 73 passages over a 5-year period. In vitro cultures of these cells were accomplished and the mRNAs were extracted prior to microinjection into Xenopus oocytes. The media examined by SE-HPLC and immunological techniques demonstrated that (1) after in vitro culture, ceruloplasmin was secreted as an uncleaved polypeptide chain with a MW of 135,000; (2) the translational product of ceruloplasmin mRNA injected into Xenopus oocytes was cleaved into fragments with MWs of 110,000, 67,000, and 50,000. The results indicate that mRNA for human ceruloplasmin can be obtained to serve as a template for the synthesis of a cDNA probe to investigate the control of human ceruloplasmin's synthesis.

Translation of messenger RNA from a renal tumor into a product with the biological properties of erythropoietin

The renal tumor RCC-3-JCK, when transplanted into immunodeficient mice, caused an erythrocytic polycythemia. When grown in culture, the tumor cells secreted a substance into the culture medium that chromatographed by size-exclusion high-performance liquid chromatography similarly to purified human erythropoietin (Ep) and was positive when assayed for Ep by its ability to stimulate erythropoiesis in fetal mouse liver cells (the FMLC assay). The poly(A) + RNA was extracted from the tumor cells and injected into Xenopus oocytes, inducing the appearance of Ep(FMLC) in the oocyte culture medium. Both the tumor cells and oocyte culture media were fractionated by size-exclusion high-performance liquid chromatography, and two fractions with Ep(FMLC) activity were found in the tumor-cell culture medium. Three active fractions were found in the medium from the mRNA-injected oocytes. The largest component from both culture media had the same elution time as a human standard (Ep). The poly(A) + RNA was fractionated by sucrose density-gradient centrifugation and the 8S and 10S fractions were found to induce Ep(FMLC) synthesis when they were injected into the oocytes. We conclude that poly(A) + RNA isolated from the Ep-producing tumor RCC-3-JCK included mRNA for Ep and that the Ep was a translational product of Xenopus oocytes injected with this mRNA.

Nucleotide and prostaglandin cycling in canine cyclic hematopoiesis

Bone marrow cells were collected from normal dogs, normal dogs made neutropenic with cyclophosphamide, and 11 dogs affected with cyclic hematopoiesis (CH) on 3 consecutive days of separate 12- to 14-day cycles. The mononuclear marrow cells from both groups of control dogs and from the CH dogs on each of 12-cycle days were cultured for 2.5 hr in serum-free media. The amounts of prostaglandins (PGF2 alpha and PGE) and cyclic GMP (cGMP) measured in the media were found to vary with the cycle in the CH dog. PGF2 alpha was highest as the dogs recovered from the neutropenia and lowest 4 days before the onset of the next neutropenic episode. Cyclic GMP was lowest 4-5 days before the onset of neutropenia, then dramatically increased as the neutropenic period approached. Cyclic GMP was highest when PGF2 alpha was lowest. Normal dogs, made neutropenic with a single dose of cyclophosphamide, had elevations of PGF2 alpha but not PGE or cGMP during the recovery period of active granulopoiesis.

A study of a Caucasian family with variant von Willebrand's disease in association with vascular telangiectasia and haemoglobinopathy

A family was identified which carries multi-haematological disorders including Type IIA von Willebrand's disease, vascular telangiectasia, and a haemoglobinopathy (haemoglobin S trait). In the affected individuals, the von Willebrand's disease varies in its expression from an asymptomatic form to a severe form especially in those patients with telangiectasia. Some patients have vascular telangiectasia in the mucous membranes of the mouth and lips. In two patients endoscopy disclosed telangiectasia in the mucous membranes of the gastrointestinal tract. All of the patients who had telangiectasia also had von Willebrand's disease. An incidental finding was the presence of an abnormal haemoglobin (haemoglobin S) in some family members. The pattern of inheritance of the haemoglobinopathy was unrelated to the inheritance pattern of von Willebrand's disease. The presence of haemoglobin S did not interfere with the aggregation of platelets in response to ristocetin.

Preparation of purified erythropoietin by high performance liquid chromatography

Highly purified erythropoietin was not available in quantities needed to carry out planned investigations and, therefore, the use of high performance liquid chromatography was explored. This technique permits the separation of proteins with high efficiency and resolution. Three types of chromatography were used. Size exclusion or gel permeation, reversed phase, and ion exchange columns were utilized with different solvent systems. The chromatographic fractions were assayed either by an exhypoxic polycythemic mouse assay or by the fetal liver cell assay. In addition, selected fractions were tested for their capability to stimulate CFU-E and BFU-E colony formation in methyl cellulose. The results of the techniques of size exclusion and ion exchange chromatography were found to be rapid and reproducible. Although reversed phase chromatography gave excellent resolution, the results were somewhat variable. Using different chromatographic combinations, erythropoietin with a specific bioactivity in the range of 50,000 u/mg protein was isolated. Although the erythropoietin gene has now been cloned and the hormone purified by utilizing monoclonal antibodies, high performance liquid chromatography may be useful in the removal of unwanted contaminants, as a tool in chemical characterization, and as a possible method for the hormone's identification and measurement in clinical laboratories.

Serum erythropoietin titers during prolonged bedrest; relevance to the "anaemia" of space flight

The overall objective of these studies was to test the hypothesis that the suppression of erythropoiesis, which occurs during both spaceflight and bedrest, was mediated by reduction in circulating levels of erythropoietin. In each of two 7-day studies, groups of subjects were exposed to either horizontal or 6 degrees head-down tilt bedrest and no evidence was obtained to suggest that the erythropoietic effects were dependent on the angle of recumbency. An additional study involved six men who were exposed to horizontal bedrest for 28 days. Serum erythropoietin titers were not significantly depressed in any of the subjects but total red cell volume was decreased. Absolute increases in red cell numbers and reductions in plasma volume both elevate the haematocrit, but our data suggest that the mechanism of erythrosuppression in these two instances may be different.

Serum erythropoietin changes in cats with feline leukemia virus-induced erythroid aplasia

Erythropoietin concentrations were increased significantly (p less than 0.025) in nine cats with natural feline leukemia virus infection and associated erythroid aplasia compared to six clinically normal cats. Adult cats experimentally inoculated with the Kawakami-Theilen isolate of feline leukemia virus developed a progressive simultaneous increase in erythropoietin activity and decrease in packed cell volume. These findings indicate that erythroid aplasia associated with feline leukemia virus infection is not caused by a failure in erythropoietin production.

Cyclic Hematopoiesis: animal models

The four existing animal models of cyclic hematopoiesis are briefly described. The unusual erythropoietin (Ep) responses of the W/Wv mouse, the Sl/Sld mouse, and cyclic hematopoietic dog are reviewed. The facts reviewed indicate that the bone marrow itself is capable of influencing regulatory events of hematopoiesis.

Cyclic hematopoiesis: human cyclic neutropenia

Human cyclic neutropenia is a relatively rare disorder of unknown etiology. Study of patients and animals with the disorder has led to important information regarding the differentiation of blood cells and control mechanisms of hematopoietic regulation. It has a world-wide distribution, occurs in both sexes, and, in about one-fourth of the patients, a family history has been obtained. While usually benign, deaths from overwhelming infections occur. In addition to cycling of neutrophils, in the majority of cases the monocytes cycle and in about one-fifth of the cases eosinophils are elevated. In a small number of patients, cycling of platelets and reticulocytes occurs. Cycles of colony stimulating factor are present. Cycles of bone marrow cells are easily demonstrable. The recent transfer of human cyclic neutropenia following allogenic bone marrow grafting confirms the hypothesis that the disorder is of bone marrow origin. The following subjects are covered in this review article: A. Definition, history, and incidence; B. Etiology, geographic distribution, mode of transmission; C. Symptoms, physical signs, diagnosis, clinical course; D. Clinical laboratory studies; E. Experimental studies; F. Prognosis; G. Treatment. It is felt that human cyclic neutropenia represents a heterogeneous group of disorders and that much remains to be learned about its cause(s).

Canine cyclic hematopoiesis: blood gas and 2,3-diphosphoglyceric acid studies

Cyclic hematopoiesis in gray Collies was first described in 1967. These dogs are anemic in comparison with the healthy littermates, and their erythropoiesis is abnormal. Although the basic disorder appears to be an as yet unidentified abnormality of hematopoietic progenitor cells, an inherent difference in responses to blood gas control mechanisms remains as a possible cause. In a study of these mechanisms in dogs with cyclic hematopoiesis, the P50 and 2,3-diphosphoglyceric acid concentrations were increased. Differences in pH, PCO2, PO2, and oxygen saturation were not observed.

Production of presumptive humoral haematopoietic regulators in canine cyclic haematopoiesis

Conditioned media (CM) were prepared according to previously published techniques from the bone marrow of dogs with cyclic haematopoiesis (CH). CM prepared from day 9 marrows inhibited mouse bone marrow CFU-s proliferation rate while CM from day 10 marrows were stimulatory and also contained an erythroid stimulating factor which appeared to be erythropoietin. In addition a highly significant trend from CM containing CFU-s inhibitory materials to media with CFU-s stimulatory activity was observed through cycles day 1 to 8. These studies further support the concept that CH is due to a defect in factors controlling stem cell proliferation and suggest that a major event occurs in CH dog marrow on days 9 and/or 10 of the cycle.

Activated factor IX complex in treatment of surgical cases of hemophilia A with inhibitors

Three patients with severe hemophilia A with inhibitors to factor VIII were treated with activated factor IX complex. Bleeding was controlled adequately during surgical procedures involving each of the three. Partial thromboplastin times showed a variable shortening and prothrombin times were significantly shortened to values less than normal. Hemostasis was substantiated by the use of epsilon aminocaproic acid. Neither anamnestic responses nor thrombotic complications were observed. A transient hypertension developed in two patients shortly after infusion with the activated factor IX complex.

Methods for the measurement of multiple parameters of erythroid regulation within individual mice

Hematocrit, hemoglobin p50, percent reticulocytes, rate of erythropoiesis using 59Fe, and blood volume were determined in individual mice using a single blood sample. Furthermore, sufficient blood remained to provide a serum pool from no more than five mice for an erythropoietin assay. These multiple procedures did not interfere with one another, and the various measurements did not need to be made immediately. Freshly prepared 51Cr-labeled erythrocytes were, however, required for blood volume determinants.

The ultrastructural immunocytochemical demonstration of erythropoietin receptors on developing erythrocytic cells of fetal mouse liver

In spite of the severe restrictions imposed by the lack of high purity erythropoietin (Ep) and Ep specific antiserum wer have attempted to demonstrate presumptive Ep binding sites on the surface of developmental forms of erythrocytic cells of the mouse fetal liver using ultrastructural immunocytochemical methodology. Cells were exposed to exogenous Ep of differing potencies and concentrations and subsequently incubated in an Ep antiserum. The Ep-Ep-antiserum complex was then visualized with a gold-labeled IgG reagent. Limited surface labeling was noted on the developing erythrocytic cells and the evaluation of the mean surface labeling densities of the erythrocytic cell series indicated that the extent of labeling was related to the stage of maturation. Early polychromatophilic erythroblasts proved to be the most heavily labeled of the erythrocytic cells followed by the basophilic erythroblast, proerythroblast and late polychromatophilic erythroblasts respectively; normoblasts, reticulocytes and erythrocytes exhibited, at most, only minimal labeling. In addition, we have been able to demonstrate several primitive cells in the fetal liver which exhibited extensive surface labeling when compared with the developing erythrocytic cells. These cells may represent the erythroid precursors of the fetal liver.

Regulation of erythropoiesis in diabetes mellitus

The regulation of erythropoiesis in 40 subjects with diabetes mellitus was investigated to test the hypothesis that increased blood concentrations of glycosylated hemoglobin would produce a reduced p50 and a compensatory increase in erythropoietin. Little evidence to support this hypothesis was observed. However, diabetes did produce complex changes in hemoglobin-oxygen releasing capacity which were compensated for in the expected way, i.e. oxygen releasing capacity showed an inverse correlation with erythropoietin. We conclude that the effects of diabetes on erythropoiesis are minor and probably have no pathological significance in most patients suffering from this disease.

Evidence that the fetal mouse liver cell assay detects erythroid regulatory factors (ERF) not measured with a standard in vivo assay

A simplified modification of the fetal mouse liver cell (FMLC) assay has been used to investigate the relationship between in vivo and in vitro detectable Erythroid Regulatory Factors (ERF) in the serum of dogs exposed to hypoxia. The results suggest that the FMLC assay is a useful technique for following changes in serum ERF. However, the data obtained cannot be directly equated with the in vivo erythrocythemic mouse assay unless a correction factor is applied. This is necessary because the in vitro assay, in general, detects 50% more ERF than does the standard mouse assay.

The in vitro growth of erythroid colonies from dog bone marrow

Enriched methyl cellulose media together with either human urinary erythropoietin or serum collected from phlebotomized dogs exposed to hypoxia was used in the study of the erythroid colony forming (CFU-E) capacity of dog marrow. The dog serum erythropoietin was found to be more efficient in stimulating CFU-E than comparable concentrations of human urinary erythropoietin. Numbers of CFU-E were directly related to the culture concentration of the stimulating serum and to the number of cells per plate. Sheep plasma erythropoietin was also found to be effective in stimulating CFU-E growth. The system described is chemically better defined and produced more consistent results than has been reported for the plasma clot method.

Ultrastructural studies on the evolution of amyloidosis in the cyclic hematopoietic (CH) dog

Electron microscopy studies were made on tissues of cyclic hematopoietic (CH) dogs of various ages presenting a high incidence of spontaneous amyloidosis. The distribution and morphologic characteristics of amyloidosis in this animal model closely correspond to the secondary and familial forms of the disease in humans. Plasma cells and, particularly, macrophages presented marked changes during the evolution of amyloid deposition. Residual bodies in the macrophages contained abundant cell debris, a result of both endocytic and autophagocytic activities. Intracellular amyloid fibrils were not observed by conventional electron microscopy. A few reticular cells contained intracytoplasmic fibrils which were morphologically different from amyloid. There was no correlation between the amount of intracellular fibrils and the size of the extracellular amyloid deposits. On the contrary, a temporal association between the magnitude of the amyloid deposits and cytoplasmic changes in the macrophages at sequential stages of the evolution of the disease was evident. It is suggested that the hematopoietic defect in the CH dog could play an important role in the production of amyloidosis, making this animal an excellent experimental model for studies of that disease.

Erythropoietic effects of space flight

Various factors which are important in the regulation of erythropoiesis have been studied in dehydrated mice in the belief that some information would be gained relevant to the erythropoietic effects of space flight. Dehydration reduced the plasma volume and, because changes in red cell volume were minimal, the hematocrit was elevated. Thus a state of relative erythrocytosis was produced. Our understanding of the mechanism whereby these changes decreased red cell production is uncertain and appears to differ somewhat from the erythroid suppression seen following elevation of the hematocrit in animals with an absolute erythrocytosis. It is suggested that factors outside of the normal erythropoietic control pathway (such as energy balance) may play an important role in the decrease in red cell volume seen in man following space flight.

Some immunological and haematological aspects of human cyclic neutropenia

In addition to standard peripheral blood cell counts, sequential studies have been made of changes in the T-lymphocyte population and in the serum titres of the presumptive humoral regulators of haematopoiesis, Colony Stimulating Activity (CSA) and Erythroid Stimulating Activity (ESA), in a young woman with cyclic neutropenia (CN). In addition, serum immunoglobulins, C3 and total complement levels and serum protein concentrations were determined on several occasions during the study. Similar tests were done concomitantly on a haematologically normal, age and sex-matched control. Cell counts on peripheral blood from the subject with CN demonstrated a clearly defined periodicity in neutrophil and monocyte concentrations and equivocal fluctuations in reticulocyte numbers. There was no evidence of periodicity in the lymphocyte concentrations and the T-lymphocyte population appeared functionally normal. Spontaneous incorporation of tritiated thymidine into peripheral blood cells showed a highly significant correlation with the monocyte count, suggesting that these cells were responsible for the radioisotope uptake. CSA titres were elevated on all occasions tested and showed no evidence of periodicity. ESA showed some evidence of cycling with elevated levels being observed during the periods of neutropenia. Serum complement levels were within the normal range but all classes of immunoglobulins were elevated and albumin levels were depressed.

Erythroid regulatory factors: correlation of detectable titers in vivo and in vitro

Titers of erythroid regulatory factors (ERF), as measured in vivo with a standard erythrocythemic mouse technique, showed a highly significant correlation with those obtained in vitro with a fetal mouse liver cell (FMLC) assay. The results from the assay in vitro were somewhat higher than would be predicted from the assay in vivo. Nevertheless, the FMLC technique has been found to be a valid and useful technique particularly in the study of serum ERF titers.

Production of erythropoietin in vitro: a review

The in vitro production of the important regulator of erythropoiesis, erythropoietin (Epo), is reviewed. It is concluded that it is possible to produce almost routinely small quantities of Epo in tissue culture. Although such procedures offer the potential to provide large quantities of the hormone for clinical use, the optimum culture conditions and mechanisms for triggering Epo production have yet to be resolved.

Evidence for the existence of an agent in the serum of the cyclic hematopoietic dog which influences hemoglobin synthesis

Serum samples collected through the cycle of a cyclic hematopoietic (CH) dog under reduced atmospheric conditions, were assayed for their ability to affect hemoglobin synthesis by normal canine bone marrow. Varying levels of hemoglobin synthesis in the presence of different serum samples suggest an agent cycles in the serum of CH dogs which influences hemoglobin synthesis.