Hair-like Projections Research Articles

A Closer Look at Sarcoptes scabiei

This image was taken from a skin scraping, prepared with mineral oil, from the chest of a 79-year-old man who complained of papular pruritic rash on his torso, arms, and legs for 6 months. He was living in a nursing care facility, unable to perform most of the daily activities because of left-sided hemiparesis secondary to a cerebrovascular accident. His white blood cell count was 8100 cells/mL with absolute eosinophilia of 2000 cells/mL (25%). He was treated with 5% permethrin, and his symptoms were relieved with fewer than 10 days of therapy. Scabies organisms produce this clinical picture after a patient acquires the organisms, Sarcoptes scabiei, from direct skin-to-skin contact or from contaminated fomites. They are ovoid organisms with a small anterior cephalic portion and a caudal thoracoabdominal portion with hairlike projections coming off from the rudimentary legs. The female mite is 0.3 mm to 0.4 mm in size, and the male mite is half the size of the female. This image shows a 6legged protonymph (original magnification 3400). Organisms burrow beneath the skin, eliciting a delayed-type hypersensitivity reaction. The diagnosis is made based on the typical distribution of the rash (interphalangeal, wrist, hands, axillary folds, and waist area) and direct examination of skin scrapings showing the mites, eggs, or scybala (packets of feces). 1 The major problem of scabies infection is the public health concern. Many infections occur in institutions caring for the elderly, such as assisted-living and nursing homes. Also at risk are infants and young children, health care workers, and immunocompromised patients. The risk factors among nursing homes for acquiring this infection include size and age of the institution and ratio of beds to

Phase II study of cladribine (2CDA) followed by rituximab for eradication of minimal residual disease (MRD) in hairy cell leukemia (HCL)

6620 Background: HCL is an indolent lymphoproliferative malignancy characterized by infiltration of the bone marrow, liver, and spleen by neoplastic B-cells with cytoplasmic hair-like projections. Despite the success of the nucleoside analogs 2CDA and pentostatin in achieving long-term remissions in HCL, some patients (pts) continue to relapse and the relapse-free survival curve does not appear to achieve a plateau. Rituximab has been used effectively to treat pts with relapsed HCL. We investigated whether the prolonged administration of rituximab one month after therapy with 2CDA can effectively eradicate MRD in pts with newly diagnosed HCL or those who have relapsed after one prior therapy. Methods: 2CDA 5.6 mg/m2 is administered over 2 hours daily for 5 days. One month later, rituximab 375 mg/m2 is administered weekly for 8 weeks. MRD is assessed by flow cytometry as well as by IgH polymerase chain reaction (PCR) assay using framework-1, -2 and -3 primer sets. MRD is evaluated at one month following 2CDA and after completion of rituximab. Results: To date, ten pts have been enrolled onto the study. Eight pts had received no prior therapy, one pt had relapsed after prior 2CDA therapy 9 years ago and one pt had received chlorambucil only. Two pts had the variant form of HCL. Six pts have completed all therapy, 3 are receiving rituximab, and 1 pt has completed 2CDA only. So far, six (100%) of the evaluable pts have achieved a complete remission (CR) with no evidence of MRD by flow in 6 and by PCR in 3. PCR remained positive in 1 pt and was not evaluable in 2 pts. Eight of 9 pts with evaluable flow studies one month after completing 2CDA remained positive; 1 pt was negative after 2CDA only and 6 became negative after completing rituximab. Five of 6 pts with evaluable PCR studies one month after completing 2CDA remained positive; 1 pt was negative after 2CDA only and 3 became negative after rituximab. Conclusions: We conclude that assessment and eradication of MRD by flow and PCR in HCL is feasible. Longer follow-up is necessary to determine whether MRD status at completion of therapy can predict relapse. This may allow design of regimens that may further improve long-term disease-free survival in HCL. No significant financial relationships to disclose.

Proventricular structure in solitary bees (Hymenoptera: Apoidea)

Proventricular structure, analyzed by scanning electronic microscopy, is compared among 28 species of solitary bees representing four families. Observations on the shapes of proventricular folds and on hair-like cuticular projections are presented, discussed, and suggested as useful to future studies of bee systematics.

The identity of Pseudomystus moeschii (Boulenger, 1890), with the description of two new species of bagrid catfishes from Southeast Asia (Teleostei: Bagridae)

The identity of the poorly known bagrid catfish Pseudomystus moeschii (Boulenger, 1890) is clarified and the species redescribed. Two new species of closely related bagrid catfishes are also described: Pseudomystus carnosus from the Way Seputih River drainage in the province of Lampung in the southern tip of Sumatra, and P. fumosus from the Pahang River drainage in eastern Peninsular Malaysia. Pseudomystus carnosus, P. fumosus and P. moeschii can be distinguished from congeners in having an enlarged posterior process of the post-temporal, presence of long hair-like epithelial projections on the skin and long tubular extensions of the sensory pores. Pseudomystus carnosus differs from the other two species in having a pointed (vs. rounded) tip of the nuchal shield, while P. fumosus differs from the other two species in having very well developed procurrent caudal rays which are sinuously curved along the anterior edges (vs. less developed procurrent caudal rays that slope evenly along the edges). A lectotype is designated for P. moeschii.

Constitutively activated Rho guanosine triphosphatases regulate the growth and morphology of hairy cell leukemia cells.

Hairy cell leukemia (HCL) is a rare type of chronic B-cell leukemia characterized by the hairy morphology of the leukemia cells. All of 5 HCL samples and an HCL-derived cell line, BNBH-I, showed serrated edges and hairlike projections in May-Grünwald Giemsa stain and protruding actin spikes and lamellipodia in phalloidin stain. These structures were hardly detected on B-cell chronic lymphocytic leukemia (B-CLL) and precursor B-cell acute lymphocytic leukemia (B-ALL) cells. Because Rho guanosine triphosphatases (GTPases) regulate the formation of these structures, we examined the expression levels and activation states of Rho GTPases in HCL cells. RhoA, Rac1, and Cdc42 were overexpressed and constitutively activated in HCL samples and BNBH-I cells but not in B-CLL or precursor B-ALL cells. Next we overexpressed dominant-negative (DN)-RhoA, DN-Rac1, and DN-Cdc42 in BNBH-I. As a result, each DN mutant repressed the growth of BNBH-I cells by more than 50% and inhibited actin spike formation, but only DN-Racl suppressed lamellipodia formation. We also found that enforced expression of constitutively active-RhoA, Rac, or Cdc42 in the proB-cell line Ba/F3 was sufficient to induce actin spike formation, whereas none of these molecules produced lamellipodia. These results indicated that constitutively activated Rho GTPases regulate the growth and unique morphology of HCL cells.

Hair-forming activity of human lymphocyte specific protein 1 requires cooperation between its caldesmon-like domains and the villin headpiece-like domains.

LSP1 is an F-actin binding with multiple F-actin binding domains. Overexpression of LSP1 in NAD 47/89 patient's neutrophils created hair-like projections on the patient's neutrophil cell surfaces and inhibited neutrophil cell motility and transfection of LSP1 in serial cell lines recreate the NAD 47/89 phenotype and produce branching hair-like surface projections. Although LSP1 contains hair-forming ability and LSP1 F-actin binding domains have been defined, the LSP1 domains responsible for its hair-forming activity, the relationship to the F-actin binding domains, and the required domain interactions, if any, for hair formation are not well understood. To define the hair-forming domains of LSP1, the relationship to the known F-actin binding domains, and binding domain interactions, LSP1 truncates, which include or exclude the different F-actin binding domains, were created by PCR. LSP1 mutants were created by site-directed mutagenesis to define the amino acids important for hair formation. Sf9 cells were infected with recombinant baculovirus expressing the cDNA of LSP1 truncates and mutants, and the morphology of infected Sf9 cells was documented by DIC optics. Results show that (1) the hair-forming activity of LSP1 is localized to the basic C-terminal half of the molecule, which contains all of the F-actin binding domains; (2) both the caldesmon-like domains and the villin headpiece-like domains are required for the hair-forming activity of LSP1; (3) basic amino acids in the villin headpiece regions are crucial for the hair-forming activity of LSP1 molecule. The results suggest cooperation between the caldesmon-like domains and the villin headpiece-like domains are required for the hair-forming activity of human LSP1 in cells.

Cytokine induction of a human acute myelogenous leukemia cell line (KG-1) to a CD1a+ dendritic cell phenotype.

Dendritic cells (DC) are highly specialized antigen-presenting cells located in many nonlymphoid tissues, and Langerhans cells (LC), a specialized form of DC, are found in the skin. LC as antigen-presenting cells play a critical role in the induction of allergic contact dermatitis. LC research is difficult because few LCs can be isolated from human skin, so efforts have focused on obtaining DCs from alternative sources. Mononuclear cells from peripheral blood and CD34+ stem cells from human cord blood and marrow can be induced to form phenotypic and functional DCs, but experiments of this type are expensive and the DC yield is low. We report here the induction of the myeloid leukemia cell line (KG-1) to a DC morphology and phenotype by culturing the cells in a defined cytokine cocktail. Morphologically, the KG-1-derived DCs are large irregularly shaped cells with prominent dendritic processes and hair-like cytoplasmic projections. Phenotypically, the KG-1-derived DCs lack lineage-specific markers, and express MHC class II, costimulatory molecules CD80 and CD86, and CD83. Functionally, KG-1-derived DCs are capable of phagocytosing latex microspheres and are able to induce a potent allogeneic T-cell response. Within the KG-1-derived DCs, a subpopulation maintains the DC phenotype and morphology described above but further develops CD1a+ marker expression similar to that of resident skin-derived LCs. These findings illustrate that phenotypic, morphologic and functional DCs can be derived from the KG-1 cell line.

Sorption of Oils by the Nonliving Biomass of a Salvinia sp.

The sorption of oils onto the dry biomass of the aquaphyte Salvinia sp. was studied at laboratory scale, and the results were compared to that obtained with a commercial oil sorbent, Peat Sorb, a processed peat. Studies included physical, chemical, and physicochemical characterization of the aquaphyte and the peat. The Salvinia sp. biomass was a better sorbent for oil than Peat Sorb (for a crude oil, 4.8 against 2.7 g of oil sorbed per g of biomass). Main factors that control the sorption process were the hydrophobicity of the biomass, particle size, the chemico-physical composition of the plant and the sorbate, and the capillary suction displayed by the plant biomass. The leaves of the plant, distributed primarily in the fraction greater than 1 mm, contain the majority of the hydrophobic groups, coming from microstructures (cuticular folds and wax crystal) and epicuticular wax. The capillarity may arise from both the micropores and from the interstices between hair-like surface projections. The roots, ma...

A comparative study of the proventricular structure in corbiculate apinae (Hymenoptera, Apidae)

The present study compares the proventricular structure, analyzed under scanning electronic microscope (SEM), among tribes of corbiculate Apinae. Fifty-one species of stingless bees (Meliponini), one species of honeybee (Apini), three species of bumblebees (Bombini) and seven species of orchid bees (Euglossini), were analyzed as in-group, and one species of sphecid wasp (Sphecidae) and two species of Halictidae bees, as out-groups. The proventricular bulb presents a basic morphology pattern similar to that of other Hymenoptera such as ants and wasps, being a symplesiomorphy for bees. The shape of proventricular folds constitutes a synapomorphy for Meliponini and an autapomorphy for Apini. The shape of hair-like projections of the cuticle that lines the proventriculus is a synapomorphy for Meliponini and Apini. These proventricular data corroborate the monophyly of the tribe Meliponini and the hypothesis that recognizes only one tribe for stingless bees. In addition, Meliponini+Apini constitutes a monophyletic group and Bombini+Euglossini another monophyletic group. The results confirm that internal morphology is a character that can be used in studies of the phylogeny in insects and the use of SEM as a powerful tool in these analyses.

Reactive synovitis of the knee joint: MR imaging appearance with arthroscopic correlation

To evaluate the use of routine MR imaging sequences in detecting and characterizing secondary reactive synovitis of the knee joint using arthroscopy as the standard of reference. Fifty consecutive patients with a history of knee pain who were referred for MR imaging and subsequently underwent arthroscopy of the knee comprised the study group. MR images were evaluated for the presence and appearance of synovitis reflected in synovial thickening and irregularity. Synovial thickening was graded on MR imaging as follows: 0=normal, 1=thin line of increased signal intensity, 2=increased signal intensity with frond-like or hair-like projections and a granular appearance of joint fluid. Standard knee imaging protocols were used. The sensitivity, specificity, and accuracy of MR imaging in detecting synovitis compared with arthroscopy were 88%, 97%, and 95%, respectively. Grade 1 synovitis was best seen on proton-density-weighted images, demonstrating increased signal intensity of the synovium against the relatively low signal intensity of the joint fluid. Grade 2 synovitis was best seen on proton-density images and T2-weighted spin echo and fast spin echo images with fat saturation, demonstrating a granular and linear hair-like appearance of joint fluid. Axial and sagittal imaging planes were most helpful in the diagnosis of synovitis. Routine MR pulse sequences are useful in identifying the presence and extent of synovial abnormalities. The detection of different stages of synovial pathology should become an important part of the evaluation of the post-traumatic patient as treatment may be altered as a result.

A Polydnavirus from the Spruce Budworm Parasitoid,Tranosema rostrale(Ichneumonidae)

The calyx epithelium of the campoplegine wasp,Tranosema rostrale, contains typical ichneumonid polydnaviruses (PVs) that display an apparently uncommon association with the egg chorion. The latter structure features fine hair-like projections, longest around the egg's apices. In the lumen of the ovary,T. rostralevirus becomes lodged between these projections and forms a particulate coat around the egg. In the host,Choristoneura fumiferana, projections and associated virions are observed in close contact with basement membranes of fat body and muscle tissues, to which the eggs rapidly become attached following introduction into the host hemocoel. We discuss the implications of this unusual virus–chorion association in terms of immune protection, delivery of virus to specific host tissues, and the evolution of PVs.

Lymphocyte-Specific Protein 1 Expression in Eukaryotic Cells Reproduces the Morphologic and Motile Abnormality of NAD 47/89 Neutrophils

AbstractDespite its name, the actin-binding protein lymphocyte-specific protein1 (LSP1) is found in all hematopoetic cells, and yet its role in cell function remains unclear. Recently, LSP1 was identified as the 47-kD protein overexpressed in the polymorphonuclear neutrophils of patients with a rare neutrophil disorder, neutrophil actin dysfunction with abnormalities of 47-kD and 89-kD proteins (NAD 47/89). These neutrophils are immotile, defective in actin polymerization in response to agonists, and display distinctive, fine, “hairlike” F-actin-rich projections on their cell surfaces. We now show that overexpression of LSP1 produces F-actin bundles that are likely responsible for the morphologic and motile abnormalities characteristic of the NAD 47/89 phenotype. Coincident with LSP1 overexpression, cells from each of several different eukaryotic lines, including a highly motile human melanoma line, develop hairlike surface projections that branch distinctively and contain F-actin and LSP1. The hairlike projections are supported at their core by thick actin bundles, composed of actin filaments of mixed polarity, which periodically anastomose to generate a branching structure. The motility of the melanoma cells is inhibited even at low levels of LSP1 expression. Therefore, these studies show that overexpression of LSP1 alone can recreate the morphologic and motile defects seen in NAD 47/89 and suggest that LSP1 is distinct from other known actin binding proteins in its effect on F-actin network structure.

Lymphocyte-Specific Protein 1 Expression in Eukaryotic Cells Reproduces the Morphologic and Motile Abnormality of NAD 47/89 Neutrophils

Despite its name, the actin-binding protein lymphocyte-specific protein1 (LSP1) is found in all hematopoetic cells, and yet its role in cell function remains unclear. Recently, LSP1 was identified as the 47-kD protein overexpressed in the polymorphonuclear neutrophils of patients with a rare neutrophil disorder, neutrophil actin dysfunction with abnormalities of 47-kD and 89-kD proteins (NAD 47/89). These neutrophils are immotile, defective in actin polymerization in response to agonists, and display distinctive, fine, "hairlike" F-actin-rich projections on their cell surfaces. We now show that overexpression of LSP1 produces F-actin bundles that are likely responsible for the morphologic and motile abnormalities characteristic of the NAD 47/89 phenotype. Coincident with LSP1 overexpression, cells from each of several different eukaryotic lines, including a highly motile human melanoma line, develop hairlike surface projections that branch distinctively and contain F-actin and LSP1. The hairlike projections are supported at their core by thick actin bundles, composed of actin filaments of mixed polarity, which periodically anastomose to generate a branching structure. The motility of the melanoma cells is inhibited even at low levels of LSP1 expression. Therefore, these studies show that overexpression of LSP1 alone can recreate the morphologic and motile defects seen in NAD 47/89 and suggest that LSP1 is distinct from other known actin binding proteins in its effect on F-actin network structure.

Three New Sarcocystis Species, Sarcocystis giraffae, S. klaseriensis, and S. camelopardalis (Protozoa: Sarcocystidae) from the Giraffe (Giraffa camelopardalis) in South Africa

Three new Sarcocystis species recovered from muscle fibers of the skeletal musculature of a giraffe in South Africa are described based on light and electron microscopy. Sarcocystis giraffae n. sp. formed slim macrocysts with a parasite-induced connective tissue encapsulation of the host muscle fiber in which the plasma membrane of the latter remained unaltered. The sarcocyst wall represented a new ultrastructural type that is characterized by fingerlike villar protrusions with a hairlike projection at the tip, containing microtubules penetrating the ground substance. Sarcocystis klaseriensis n. sp. formed small filiform microcysts with kinked finger-shaped villar protrusions of the wall, containing scattered microtubules or filaments, and represented another new ultrastructural type. Sarcocystis camelopardalis n. sp. formed small filiform microcysts with straplike villar protrusions of the wall, containing chainlike osmiophilic structures, and represented again a new ultrastructural type.

Ultrastructural characterization of the nasal respiratory epithelium in the piglet.

Very little information is available on the ultrastructure of the nasal cavity epithelium of the piglet. However, the nasal respiratory epithelium plays an important role in the pathology of atrophic rhintis of the piglet. Indeed, ciliated cells and mucus play a co-ordinate role in the colonization of the nasal cavity by the etiological agents of the disease. In the present study, samples of the ventral nasal turbinates of germ-free piglets were processed for observation in the transmission electron microcope to describe the ultrastructure of their covering respiratory epithelium. Five morphologically distinct cell types were observed. Ciliated cells and basal cells were similar to that described in the nasal cavity of other species. On the basis of their secretory granule morphology, five forms of goblet cells were observed. Nonciliated, nonsecretory columnar cells with short, thick, regularly and densely spaced apical microvilli were identified as brush cells. A distinct type of secretory cells was found. Their apical surface protruded above the adjacent cells and had a few microvilli covered with thin hairlike projections. They were rich in smooth endoplasmic reticulum and had an apocrinelike type of secretion. These findings indicate the complexity of cell types of the piglet nasal respiratory epithelium.

Ultrastructural characterization of the nasal respiratory epithelium in the piglet

Background Very little information is available on the ultrastucture of the nasal cavity epithelium of the piglet. However, the nasal respiratory epithelium pays an important role in the pathology of atrophic rhintis of the piglet. Indeed, ciliated cells and mucus play a coordinate role in the colonization of the nasal cavity by the etiological agents of the disease. Methods In the present study, samples of the ventral nasal turbinates of germ-free piglets were processed for observation in the transmission electron microcope to describe the ultrastructure of their covering respiratory epithelium. Results Five morphologically distinct cell types were observed. Ciliated cells and basal cells were similar to that described in the nasal cavity of other species. On the basis of their secretory granule morphology, five forms of goblet cells were observed. Nonciliated, nonsecretory columnar cells with short, thick, regularly and densely spaced apical microvilli were identified as brush cells. A distinct type of secretory cells was found. Their apical surface protuded above the adjacent cells and had a few microvilli covered with thin hairlike projections. They were rich in smooth endoplasmic reticulum and had an apocrinelike type of secretion. Conclusions These findings indicate the complexity of cell types of the piglet nasal respiratory epithelium. © 1996 Wiley-Liss, Inc.

Seed Epidermis Development and Histochemistry in Solanum melongenaL. and S. violaceumOrt.

Structure, development and histochemistry of the seed epidermis were studied in Solanum melongenaL. and S. violaceumOrt. using light and scanning electron microscopy. The epidermal cells at the endosperm mother cell stage of ovule development had thickened outer periclinal walls, consisting of two layers, a thin inner layer, and a thick outer layer. The latter which stained positively for pectic substances became further thickened during the course of seed development; more so in S. melongena. The inner layer of the outer periclinal wall also was thickened by depositions of cellulose but remained comparatively thin. The development of the inner periclinal and anticlinal walls took place by the uneven deposition of concentric layers. These secondary wall thickenings which appeared as pyramids in transverse section stained for cellulose, lignin and pectin. Further uneven secondary thickenings near the outer part of the anticlinal walls resulted in the formation of projections which were hair- or ribbon-like in appearance. In S. melongena, these projections progressed only a short distance from the anticlinal wall. In S. violaceum, on the other hand, they grew much longer forming striations on the inside of the outer periclinal wall. In S. melongena, partial removal of the outer periclinal wall by enzyme etching exposed to surface view a beaded appearance of the cell boundaries. Complete erosion of the outer periclinal wall revealed the hair-like projections of the underlying anticlinal walls. In S. violaceum, enzyme treatment exposed the striations which formed bridge-like structures over the curves in the anticlinal walls.

Assembly and function of Chlamydomonas flagellar mastigonemes as probed with a monoclonal antibody.

Mastigonemes are hair-like projections on the flagella of various kinds of lower eukaryotes. We obtained a monoclonal antibody (mAb-MAST1) to mastigonemes of Chlamydomonas reinhardtii, and found that it reacts with a single flagellar glycoprotein of about 230 kDa. Interestingly, immunofluorescence microscopy demonstrated that mAb-MAST1 recognizes not only the flagellar mastigonemes but also a ring composed of 10 or more particles located in the anterior end of the cell body close to the flagellar bases. The ring structure may be the pool of the mastigoneme protein. When the flagella are amputated, they regenerate to their original length in 90-120 minutes. We found that mastigonemes appear on the new flagellar surface as early as 15 minutes after deflagellation, and that new mastigonemes are mostly assembled onto the distal region of the flagellar surface. Mastigonemes thus appear to be inserted into the membrane only in the distal region of the flagellum. Alternatively, mastigonemes may be inserted at the base and transported very rapidly to the distal portion where they are trapped. When live cells are treated with mAb-MAST1, mastigonemes disappear from the flagellar surface. In these mAb-MAST1 treated cells, the swimming velocity decreases to 70-80% of the normal value, although the flagellar beat frequency increases to approximately 110% of the control. These findings demonstrate vectorial transport of mastigonemes to their assembly sites, and show that mastigonemes function to increase flagellar propulsive force by increasing the effective surface of the flagellum.

口腔毛状白板症に類似した白色病変の１例

Oral hairy leukoplakia (HL) is clinically characterized as a white lesion of the lateral portion of the tongue among persons who are human immunodeficiency virus seropositive. The lesion shows a hairy or corrugated appearance.The dominant histologic features of HL are epithelial hyperparakeratosis with hairlike projection, acanthosis, vacuolated cellsresembling koilocytes and an absence of inflammation in the connective tissue.We have recently reevaluated seventy seven white lesions cases which were diagnosed as leukoplakia both clinically and histologically, and found out three white lesions cases mimicking HL.Herein is a report of a case with marked oral mucosal involvement together with an examination of Langerhans cells (LC).The clinical and histologic features of this case were very similar to HL and epithelial LC were detected in reduced numbers.

Sarcocystis kirkpatricki n. sp. (Apicomplexa: Sarcocystidae) in Muscles of Raccoons (Procyon lotor) from Illinois

Sarcocysts of Sarcocystis kirkpatricki n. sp. (Apicomplexa: Sarcocystidae) are described from the skeletal and heart musculature of 66 (66%) of 100 raccoons (Procyon lotor) from Illinois. Histologic examination of muscle tissues from tongue, diaphragm, esophagus, and heart revealed that 61%, 47%, 32%, and 2%, respectively, contained sarcocysts of this species. Juvenile raccoons (less than 1 yr old) were more likely (P less than 0.01) to have sarcocysts in the tissues examined (52/60 or 87%) than were adults (14/40 or 35%). Histologically, sarcocysts in the 4 tissues were similar: the cyst wall was 2-3 microns thick, PAS negative, and had fine hairlike surface projections; interior septa were indistinct. Ultrastructurally, sarcocyst walls had short (mean = 2.8 microns), straight to sloping, villuslike projections. Longitudinal tubular filaments inside these projections extended from the tips to the base, where they terminated in a granular electron-dense layer of the primary cyst wall. Thin septa were within the sarcocysts. Feeding experiments utilizing dogs and cats as potential definitive hosts were negative.