Hematologic reference values for the fetal long-tailed macaque (Macaca fascicularis)

Complete blood counts (CBCs) were performed on 68 fetal macaque blood samples collected from 31 fetuses by repeat ultrasound-guided cardiocentesis (gestational day [GD] 80–150; term ～ GD 165) with the goal of defining normative hematologic reference values during prenatal life. Lymphocytes were the primary white blood cells (WBCs) observed throughout gestation. Segmented neutrophils were the second highest percent of WBCs and were noted to rise significantly during GD 130–140. Overall, WBCs increased progressively throughout gestation with a transient decline at the beginning of the third trimester (～ GD 110). A steady linear rise in red blood cells (RBCs), hemoglobin, and hematocrit was observed with a marginal decline close to term; mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) showed a consistent linear decline throughout gestation whereas mean corpuscular hemoglobin concentration (MCHC) remained relatively stable. Nucleated RBCs (NRBCs per 100 WBCs) were present on GD 80, showed a sharp decline mid-second trimester (～ GD 90), and were significantly diminished by the beginning of the third trimester (～ GD 110). No quantitative changes in platelets were noted throughout the study period. Evaluations of erythrocyte morphology indicated polychromasia and anisocytosis as typical characteristics throughout gestation with rare occurrence of hypochromasia and poikilocytosis. Howell-Jolly bodies were intermittently observed. These data reveal distinct similarities when compared to prenatal hematologic characteristics for human fetuses and provide baseline data which can be applied to experimental studies where prenatal hematopoietic/hematologic toxicity may be anticipated. © 1993 Wiley-Liss, Inc.     

Concentrations of elements in rat thymocytes measured by X-ray microanalysis

Summary Elemental concentrations of rat thymocytes in vivo were studied by X-ray microanalysis of freeze-dried sections. Cells from different regions, the subcapsular zone, the cortex and the medulla were studied in thymic tissue from a number of animals. Generally thymocytes situated in the medulla had higher concentrations of K compared to those in the subcapsular zone. The concentration of Na in the nucleus was constant in the medulla in all animals but some variation in this element was seen between animals in the subcapsular zone. The distribution of K/Na ratio in individual thymocytes was different in each region of the thymus. Cells with low K/Na ratio (<5) were predominant in the subcapsular zone, whereas cells with higher values for K/Na ratio were found in the cortex and medulla. The subcapsular zone is the region where mitotic cells are mostly situated. The finding of thymocytes with higher concentrations of Na and low K/Na ratios in this region is in accord with in vitro studies on thymocyte stimulation.     

Analysis of age-associated changes in collagen crosslinking in the skin and lung in monkeys and rats

The present study was designed to address a specific question: can we define collagen aging in vivo in terms of alterations in collagen crosslinking? In order to assess the complete spectrum of change throughout life, tissues from rats, monkeys and (where available) humans were examined at ages ranging from fetal to old. Skin and lung were selected in order to include all of the crosslinks derived from lysyl oxidase-generated aldehydes that have been identified thus far, both reducible and nonreducible. Crosslinks analyzed included hydroxylysinonorleucine, dihydroxylysinorleucine, histidinohydroxymerodesmosine, hydroxypyridinium, lysyl pyridinium, and a deoxy analogue of hydroxypyridinium found in skin that differs structurally from lysyl pyridinium. Tissues from both a short-lived species (rats) and a long-lived species (monkeys) were analyzed to test further the hypothesis that changes in crosslinking are linked predominantly to biological age of the animal, rather than temporal aging. We found that biological aging seems to regulate certain predictable changes during the first part of the lifespan: the disappearance postnatally of dihydroxylysinonorleucine in skin, the rapid decrease in difunctional crosslink content in lung and skin during early growth and development, and the gradual rise in hydroxypyridinium and lysyl pyridinium in lung tissue. Changes in crosslinking were far less predictable during the second half of the lifespan. Although hydroxypridinium content continued to rise or reached a plateau in rat and monkey lungs, respectively, it showed a decrease in human lungs. The analogous trifunctional crosslink in skin, the so-called 'pyridinoline analogue', decreased dramatically in both rats and monkeys in later life. Our data suggest that caution must be taken in drawing inferences about human connective tissue aging from experiments performed in short-lived species such as rodents. Furthermore, the finding that there may be fewer total lysyl oxidase-derived crosslinks per collagen molecule in very old animals as compared with young animals suggests that we may need to expand our concepts of collagen crosslinking.     

Identification of the Toxoplasma gondii mitochondrial ribosome,and characterisation of a protein essential for mitochondrial translation

Apicomplexan parasites cause diseases such as malaria and toxoplasmosis. The apicomplexan mitochondrion shows striking differences from common model organisms, including fundamental processes such as mitochondrial translation. Despite evidence that mitochondrial translation is essential for parasite survival, it is largely understudied. Progress has been restricted by the absence of functional assays to detect apicomplexan mitochondrial translation, a lack of knowledge of proteins involved in the process and the inability to identify and detect mitoribosomes. We report the localization of 12 new mitochondrial proteins, including 6 putative mitoribosomal proteins. We demonstrate the integration of three mitoribosomal proteins in macromolecular complexes, and provide evidence suggesting these are apicomplexan mitoribosomal subunits, detected here for the first time. Finally, a new analytical pipeline detected defects in mitochondrial translation upon depletion of the small subunit protein 35 (TgmS35), while other mitochondrial functions remain unaffected. Our work lays a foundation for the study of apicomplexan mitochondrial translation.