Loss of lineage antigens is a common feature of apoptotic lymphocytes

The analysis of apoptosis in cell populations involves the detection of their specific lineage antigen (LAg) expression. This experimental approach relies on their assumed constant expression, but it is unclear whether such expression is actually maintained during cell death. We examined whether the loss of LAgs is a common feature of apoptotic lymphocytes and whether some might completely lose their LAgs. The changes in the expression of CD3, CD5, CD8, CD4, CD28, CD56, and CD19 were monitored in highly purified lymphocyte populations obtained by negative selection in a fluorescence-activated cell sorter. These were cultured for 24 h with or without phytohemagglutinin or staurosporin. For each LAg-positive subset studied, apoptosis was consistently more common among cells showing partial or total loss of LAg expression compared with cells maintaining their initial LAg levels. The kinetics of expression loss was rapid for CD8, CD56, and CD28, and more than 80% of initial expression was lost in the early stages of apoptosis but was slower for CD3, CD5, and CD4. For CD3 and CD5, expression was dependent on the apoptotic stimulus used. It is interesting that loss of antigen expression was independent of cell size. This phenomenon was also found in nonmanipulated, highly pure CD19 B lymphocytes of peripheral blood mononuclear cells from B chronic lymphocytic leukemia patients. Loss of LAg expression appeared to be a common feature of apoptotic lymphocytes under all the conditions assayed. The different kinetic patterns of LAg loss suggest apoptotic cells might actively regulate this process.     

Spermiogenesis in the proteocephalidean cestode<Emphasis Type="Italic"> Proteocephalus torulosus</Emphasis> (Batsch, 1786)

Spermiogenesis of the proteocephalidean cestode Proteocephalus torulosus (Batsch, 1786) was examined for the first time using transmission electron microscopy. Spermiogenesis begins with the formation of a distal cytoplasmic protrusion, a differentiation zone, at the periphery of the early spermatid. This differentiation zone is lined with cortical microtubules and contains two centrioles aligned along the same axis. Subsequently, each centriole is associated with the striated root and the intercentriolar body appears between them. A flagellar bud arises from each centriole, growing later as a free flagellum. Simultaneously, a median cytoplasmic process (MCP) develops distally to the flagella. The two flagella, which are of unequal length, become longer and rotate towards the MCP. At this stage, two arching membranes appear at the base of the differentiation zone. The nucleus elongates and when both flagella are fused with the MCP, the nucleus subsequently migrates into the MCP. Finally, the advanced spermatids detach from a condensing residual cytoplasm at the level of the arching membranes.     

Yq deletion with short stature, abnormal male development, and schizoid character disorder.

A 33-year-old male with short stature, abnormal male sexual differentiation, aspermia, and schizoid character disorder is described, who had a Y chromosome with a deleted long arm. The correlation of the symptoms, including the psychotic abnormality, with the cytogenetic finding is discussed.     

The effect of long-term stimulation of fast muscles on their blood flow,metabolism and ability to withstand fatigue

Chronic stimulation of fast rabbit muscles (tibialis anterior, extensor digitorum longus and the peroneal muscle group) at a frequency naturally occurring in nerves to slow muscles increased their ability to withstand fatigue. Isometric tension decreased during a 10-min period of contractions at 4 Hz by 75% in control muscles, but only 55% in muscles chronically stimulated for 4 days, and 23% in muscles stimulated for 28 days. Chronic stimulation had little effect on resting blood flow, oxygen or glucose consumption. The output or consumption of lactate and free fatty acids (FFA) at rest were also unaffected. The glycogen content was regularly increased, and was apparent after only 2 days of stimulation. The activity of fatty acid activating enzyme was increased after 28 days. During a 10-min period of isometric contractions at 4 Hz, there was a markedly greater increase in blood flow and oxygen consumption in muscles stimulated for 14-28 days than in control muscles; lactic acid output was lower in muscles stimulated for 28 days, and the uptake of FFA was significantly higher. It is therefore suggested that muscles chronically stimulated for 14-28 days use fats as the main source of energy during isometric contractions. The predominantly oxidative metabolism is probably facilitated by the higher density of capillaries. The latter also enables more efficient delivery of oxygen, and therefore smaller fatiguability, already after 4 days of chronic stimulation.     

Neuronal expression of Raf protooncogene in the brain stem of adult guinea pig

The Raf protooncogenes encode for cytoplasmic serine/threonine-specific protein kinases which can be activated via growth factor receptors by phosphorylation. Immunohistochemical and Western blotting studies have proven the existence of Raf protein kinases in neurons of the cerebral cortex of rats and guinea pigs. The aim of the present study was to map the immunohistochemical distribution of Raf kinase-like staining in the brain stem of guinea pig. Polyclonal antibodies were used that were raised against a recombinant viral protein in combination with the avidin-biotin-peroxidase system for detection of immunoreactivity. Specificity of the antibodies was tested in Western blotting experiments. Cytoplasmic immunostaining was observed in motor nuclei of hypoglossal, accessory, vagus, facial, trigeminal, abducent, oculomotor and trochlear nerves, and in the nucleus ambiguus, nucleus retroambigualis, lateral vestibular nucleus, mesencephalic nucleus of the trigeminal nerve, the red nucleus, raphe nuclei and reticular formation. Scattered neurons were stained in other sensory nuclei, such as solitary tract nuclei, medial, dorsal and ventral vestibular nuclei and cochlear nuclei. The spinal trigeminal nucleus and the main sensory nucleus of the trigeminal nerve contained few medium-sized immunoreactive cells. In general, staining was mainly somatodendritic; the axonal plexus was not positive. It is concluded, that the widespread neuronal appearance of cytoplasmic Raf kinase suggests an important role in transmission of trophic and growth factor signals in these neurons.     

Prognostic significance of del(20q) in patients with hematological malignancies

Deletions of the long arm of chromosome 20 represent a common chromosomal abnormality associated with myeloid malignancies, in particular with myeloproliferative disorders (MPD), myelodysplastic syndromes (MDS), and acute myeloid leukemia (AML). Using G-banding cytogenetic techniques, we found clones with del(20q) in 36 patients with hematological malignancies examined in our laboratory during the years 2001–2003: in 23 patients as a sole cytogenetic aberration and in 13 patients together with other chromosomal changes. Fluorescence in situ hybridization (FISH) with a probe specific for the 20q12 region was used in all cases to confirm the presence of the clone with deletion. For patients with additional or complex chromosomal rearrangements, multicolor FISH (M-FISH) analysis was performed. Statistical evaluation of the prognostic impact of sex, age, diagnosis, and karyotype was performed. The survival time correlated with the type of chromosomal aberration; no significant differences in survival were found for sex, age, and diagnosis.     

Biochemical characterization of new strains of<Emphasis Type="Italic"> Trypanosoma cruzi</Emphasis> and<Emphasis Type="Italic"> T. rangeli</Emphasis> isolates from Peru and Mexico

Seven trypanosome stocks isolated have been characterized by lectin agglutination, isoenzyme analysis, and the end products excreted. The stocks were isolated from different geographic areas—one from Mexico (TM5), and six from Peru, four of these isolated from different species of triatoma (TP504, TP702, TP704 and TP706), the other two isolated from the salivary glands of Rhodnius ecuadorensis (TRa605 and TRa606). Additionally, one strain of Trypanosoma cruzi isolated from a human case (strain TC-Maracay) and one strain of T. rangeli (TRa, Cajamarca-Peru strain), characterized and maintained in our laboratory, were used as reference strains. According to statistical study, the stocks were grouped into three clusters: (1) cluster I included the reference strain of T. cruzi (TC-Maracay); (2) cluster II was subdivided into two groups—subcluster IIA for the Mexican isolate (TM5) and subcluster IIB for the Peruvian ones, isolated from the salivary glands of Rhodnius ecuadorensis (TRa 605 and TRa 606) and the reference strain T. rangeli (TRa); these two new isolates were classified as T. rangeli; and (3) cluster III for the rest of the Peruvian isolates, which should be considered at least as a different strain from the T. cruzi strain Maracay. We show that the identification of T. cruzi and T. rangeli in mixed infections is readily achieved by biochemical methods. These findings identified three clusters of Mexican and Peruvian stocks that correlate with geographic origin, although assignment to a T. cruzi linage was not possible.     

Currant allergy and the Rosaceae-grass pollen allergy syndrome: a case report.

BACKGROUND: Despite the increasing use of currants in culinary recipes, currant allergy has rarely been reported. OBJECTIVES: To study a case of currant allergy and to explore cross-reactivity between grass pollen and Rosaceae family fruit allergens. METHODS: Skin prick tests to pollen and skin prick-to-prick tests with currants and peach were performed. Specific IgE levels were determined using the CAP method. We prepared a protein extract of 0.1 mg/mL in phosphate-buffered saline using red currant in the presence of protease inhibitors. Immunoblot inhibition studies were performed to explore cross-reactivity between grass pollen and currant allergens. RESULTS: Skin prick test results were positive to Dactylis, arizonic, and olive pollens. Results of skin prick-to-prick tests with fresh red and black currants were negative and positive, respectively, to peach. The specific IgE level was 5.7 KU/L to red currant and 2.92 KU/L to peach (CAP). Western blot analysis with red currant extract revealed specific IgE protein bands of 37 and 26 kDa. Preincubation of sera with extracts from red currant and peach inhibited both IgE bands, and preincubation with Dactylis pollen inhibited the 37-kDa band only. CONCLUSIONS: We report a case of allergy to grass pollen with an oral allergy syndrome involving several fruits from 2 different families of the Rosidae subclass confirmed by in vitro tests. Inhibition studies demonstrated cross-reactivity between different fruits (currant and raspberry) from the Rosidae subclass and were incomplete with grass pollen allergens.