bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Journey of Malaria Sporozoites in the Mosquito Salivary Gland
Authors: PIMENTA PAULO F. , TOURAY MUSA , MILLER LOUIS 
Published: May 2007

ABSTRACTThe life cycle of malaria parasites in the mosquito vector is completed when the sporozoites infect the salivary gland and are ready to be injected into the vertebrate host. This paper describes the fine structure of the invasive process of mosquito salivary glands by malaria parasites. Plasmodium gallinaceum sporozoites start the invasion process by attaching to and crossing the basal lamina and then penetrating the host plasma membrane of the salivary cells. The penetration process appears to involve the formation of membrane junctions. Once inside the host cells, the sporozoites are seen within vacuoles attached by their anterior end to the vacuolar membrane. Mitochondria surround, and are closely associated with, the invading sporozoites. After the disruption of the membrane vacuole, the parasites traverse the cytoplasm, attach to, and invade the secretory cavity through the apical plasma membrane of the cells. Inside the secretory cavity, sporozoites are seen again inside vacuoles. Upon escaping from these vacuoles, sporozoites are positioned in parallel arrays forming large bundles attached by multilammelar membrane junctions. Several sporozoites are seen around and inside the secretory duct. Except for the penetration of the chitinous salivary duct, our observations have morphologically characterized the entire process of sporozoite passage through the salivary gland.
Immunoelectron Microscopy of Giardia lamblia Cytoskeleton Using Antibody to Acetylated α‐Tubulin
Authors: SOLTYS BOHDAN J. , GUPTA RADHEY S. 
Published: May 2007

ABSTRACT Giardia lamblia trophozoites contain acetylated α‐tubulin but lack detectable levels of tyrosinolated α‐tubulin, as demonstrated in immunoblots with monoclonal antibodies specific for these tubulin forms. By immunofluorescence microscopy, acetylated α‐tubulin is localized in axonemes, median bodies and in the adhesive disk. Post‐embeddment immunogold labeling of thin sections of cells was used to evaluate acetylation at the level of individual microtubules by electron microscopy. Cells were fixed with glutaraldehyde and embedded in the acrylic resin LR Gold. Results indicate all microtubules in adhesive disk, axonemes, basal bodies, funis and the median bodies contain acetylated α‐tubulin. Unlike immunofluorescence labeling, all microtubules of the adhesive disk and the funis could be gold labeled. No nonspecific labeling of the cytoplasm or of structures other than microtubules was observed. Acetylated microtubules in G. lamblia do not appear to be a subset of microtubules and acetylation appears uniform along the entire length of individual microtubules. Acetylation and the tyrosinolation state of microtubules in Giardia are discussed in the context of microtubule stability and crosslinked features of the cytoskeleton.
Incorporation of Fatty Acids and Amino Acids by Cultured Pneumocystis carinii
Authors: PAULSRUD JOHN R. , QUEENER SHERRY F. 
Published: May 2007

ABSTRACTCultured P. carinii rapidly took up a variety of fatty acids. The relative rates of uptake for four fatty acids were 18:1 >> 16:0 ≅ 18:0 ≅ 18:2. Fatty acids were primarily incorporated into phospholipids and the uptake process was specifically inhibited by 2.2 and 22 μM primaquine, a concentration having no effect on host cells. Amino acids were also taken up by cultured P. carinii in a primaquine sensitive process. Radiolabeled leucine was incorporated into the major surface glycoprotein of P. carinii. The formation of radioactive P. carinii‐specific proteins indicated that the cultured organisms carried out transcription and translation and that the incorporation of amino acids was dependent upon P. carinii rather than rare HEL human embryonic lung cells. The spinner flask culture system provides convenient access to P. carinii for metabolic studies in defined medium for a period of 5–14 days after inoculation.
F‐actin Distribution of Dictyostelium Myosin I Double Mutants
Authors: PETERSON MICHELLE D. , TITUS MARGARET A. 
Published: May 2007

ABSTRACTThe roles of the myosin I class of mechanoenzymes have been investigated by single and double gene knockout studies in the amoeba Dictyostelium discoideum. Cells lacking different myosin I pairs (myoA‐/myoB‐, myoB‐/myoC‐, and myoA‐/myoC‐) were examined with respect to their cytoskeletal organization. F‐actin localization by rhodamine‐phalloidin staining of cells indicates that the myoA‐/myoB‐, myoB‐/myoC‐, and myoA‐/myoC‐ cells appear to redistribute their F‐actin more slowly than wild type cells upon adhesion to a substrate. These studies suggest that Dictyostelium myoA, myoB, and myoC may have overlapping roles in maintaining the integrity or organization of the cortical membrane cytoskeleton.
Polymorphism of the Thymidylate Synthase Gene of Pneumocystis carinii from Different Host Species
Authors: MAZARS EDITH , ÖDBERG‐FERRAGUT CARMEN , DEI‐CAS EDUARDO , FOURMAUX MARIE‐NOELLE , ALIOUAT EL MOUKHTAR , BRUN‐PASCAUD MONIQUE , MOUGEOT GENEVIEVE , CAMUS DANIEL 
Published: May 2007

ABSTRACT Pneumocystis carinii is an opportunistic agent found in the lung of various mammals which often causes severe pneumonia in immunocompromised humans, especially in AIDS patients. In the past several years significant additions have been made to the collection of knowledge we have concerning the genetic diversity of P. carinii. These additions provide new understanding of Pneumocystis transmission and the effect of possible reservoirs of Pneumocystis in the various species. In this study, a 400‐bp fragment of the thymidylate synthase (TS) gene of P. carinii has been amplified by PCR from 43 parasite isolates obtained from 4 mammalian host species: rat, mouse, rabbit and human. A probe selected from the TS gene sequence of rat‐derived P. carinii was hybridized with the amplified products from rat‐ and mouse‐derived P. carinii, but not with rabbit or human P. carinii DNA. Restriction profiles were performed on amplified fragments from all isolates, and the 4 nucleotide sequences of the TS gene fragment amplifed from rat, mouse, rabbit and human P. carinii were determined. Differences were detected in the gene fragment in P. carinii isolates from the 4 host species; however no difference was revealed in P. carinii isolates within a single host species, whatever the host strain or its geographic origin. Thus, the sequence differences of the P. carinii TS gene appeared as host‐species specific. A specific probe which recognized all human P. carinii isolates was defined.
Isotricha jalaludinii N. Sp. Found from the Rumen of Lesser Mouse Deer, Tragulus javanicus, in Malaysia
Authors: IMAI SOICHI , KUDO HIROSHI , FUKUTA KATSUHIRO , ABUDULLAH NORHAMI , HO YIN‐WAN , ONODERA RYOJI 
Published: May 2007

ABSTRACT Isotricha jalaludinii n. sp. found in the rumen of lesser mouse deer, Tragulus javanicus, in Malaysia was described and illustrated. This new species is characterized by the location and direction of the vestibulum, shape of the macronucleus, and absence of a dent at the vestibular opening. The presence of single peculiar isotrichid species in the rumen of mouse deer, which is recognized as one of the most primitive ruminants, suggests that the isotrichid ciliates similar to I. jalaludinii and Isotricha intestinalis were established at a fairly early period during the evolution of ruminants.
Choanoflagellates (Sarcomastigophora, Protozoa) from the Coastal Waters of Taiwan and Japan. I. Three New Species
Authors: HARA SEIKO , CHEN YUH‐LING L. , SHEU JIA‐CHI , TAKAHASHI EIJI 
Published: May 2007

ABSTRACTThree new acanthoecidaean species collected from the coastal waters of Taiwan and Japan are described: Acanthocorbis camarensis n. sp. resembles Acanthocorbis unguiculata in lorica morphology, but differs in having regularly arranged longitudinal and transverse costae at the anterior lorica chamber, and in lacking a nail at the apical end of anterior spine; Diaphanoeca spiralifurca n. sp. is characterized by the spiral arrangement of the costal strips in the posterior half of the lorica chamber and is closely related to Diaphanoeca grandis; Stephanoeca supracostata n. sp. is closely related to Stephanoeca elegans, but differs in having an additional transverse costa at the anterior lorica chamber.
Experimental tissue cyst induced Toxoplasma gondii infections in dogs
Authors: LINDSAY D. S. , DUBEY J. P. , BUTLER J. M. , BLAGBURN B. L. 
Published: May 2007

SUMMARYTissue cyst induced Toxoplasma gondii infections were examined in 2 beagle dogs orally inoculated with tissue cysts. Neither dog developed clinical signs of toxoplasmosis. Both dogs developed low antibody titers to T. gondii. The MAT and IFAT were superior to the LAT and IHT tests for detecting antibodies to T. gondii.
Leishmania donovani Attachment Stimulates PKC‐Mediated Oxidative Events in Bone Marrow‐Derived Macrophages
Authors: BHUNIA ANIL K. , SARKAR DWIJEN , DAS PIJUSH K. 
Published: May 2007

SUMMARYWe investigated activation signaling events in bone marrow‐derived macrophages after infection with Leishmania donovani, an intracellular parasite of macrophages. Leishmania donovani infection caused a general suppression of activation parameters like O2‐ and NO production. However, conditions which allow parasite attachment and prevent entry resulted in triggering of O2‐ and NO production and stimulation of O2 consumption. Optimal NO and O2‐ production occurred when bone marrow‐derived macrophages and Leishmania ratio was 1:100. The activation signal for O2‐ production was initiated 15 min after parasite attachment, whereas augmentation of NO production started 6 h after attachment. Activation of O2‐ and NO generation by L. donovani attachment was inhibited by staurosporine as well as by prolonged treatment of phorbol myristate acetate suggesting a protein kinase C‐dependent mechanism. Translocation studies showed that protein kinase C activity in cell membrane fraction rapidly and transiently increased following parasite attachment. No such protein kinase C translocation event occurred in L. donovani infected bone marrow‐derived macrophages. Phorbol myristate acetate was found to stimulate membrane translocation of protein kinase C in parasite attached cells whereas it was impaired in infected cells. However, both attachment and infection induced a similar shift of phorbol receptors from cytosolic to membrane fraction indicating that in infected cells the translocation of protein kinase C protein was not impaired but the activity of the membrane associated enzyme was somehow inhibited. These results suggest that although internalization of intracellular parasites like L. donovani caused inhibition of nitrite and superoxide release, mere attachment on macrophage surface resulted in an activation of protein kinase C‐mediated downstream oxidative events.
Cultivation of Rabbit Pneumocystis carinii on Cells Derived from Rabbit (Oryctolagus cuniculus)
Authors: POLACK BRUNO , CERÉ NICOLAS , RHUN DANIELLE LE , GUILLOT JACQUES , CHERMETTE RENÉ 
Published: May 2007

SUMMARY. Cultivation of Pneumocystis carinii from rabbit onto cell monolayers was intended. Three cell types were used: rat lung derived cell line L2 and canine kidney derived cell line MDCK, and primary epithelial rabbit lung cells derived from 20 days old foetuses. These primary cells were also immortalized by transfection of the coding sequences for the large and small T antigens of the SV40 virus. P. carinii were extracted from lungs of corticoid treated young rabbits and were purified on Ficoll. In vitro development of P. carinii was assessed by counting the number of attached parasites on cells after staining. No development was observed on L2 and MDCK cell lines. On the contrary, a development was observed on rabbit derived cells with a threefold increase of attached parasites on the third day of culture. Immortalized cells allowed also multiplication of attached P. carinii. These results are similar to those obtained with culture of rodent P. carinii onto cell monolayers.
Ubiquinone Synthesis by Pneumocystis carinii: Incorporation of Radiolabeled Polyprenyl Chain and Benzoquinine Ring Precursors
Authors: SUL DONGGENUN , KANESHIRO EDNA S. 
Published: May 2007

SUMMARYRadiolabeled mevalonic acid was incroporated in vitro into Pneumocystis carinii ubiquinone homologs, CoQ9 and CoQ10, dermostrating the isoprenoid branch pathway forming the polyprenyl chain of ubiquinone is functional in the organism. Radiolabeled shikimic acid, tyrosine and p‐hydroxybenzoic acid were also incorporzated into the two ubiquinone homologs, indicating that P. carnii also possesed the biological pathway for de novo synthesis of the CoQ benzoquinone ring.
Microsporidiosis in HIV‐Positive Children in Madrid (Spain).
Authors: AGUILA CARMEN DEL , NAVAJAS RAQUEL , GURBINDO DOLORES , RAMOS JOSE TOMAS , JOSE MELLADO M , FENOY SOLEDAD , ANGELES MUÑOZ FERNANDEZ M , SUBIRATS MERCEDES , RUIZ JESUS , PLENIAZEK NORMAN J. 
Published: May 2007

SUMMARYA prospective study was carried out to determine the prevalence rates of microsporidiosis and other enteroparasites in HIV‐positive children in the Madrid area. HIV‐positive pediatric patients from three hospitals were entrolled in the study. A total of 293 samples (158 stool and 127 urine) were collected from 83 children whose mean age was 6.3 years and hed a mean CD4 count of 504.7/mm3 (range 1‐2,220/mm3), 48 of whom suffered diarrhea at the time of the study. Microsporidia indentification was investigated in stool and unrine samples using Weber's chromotrope‐based strain, IIF and PCR species‐specific tests. Enteric parasites were identified in 32.5% of the children. Cryptosporidium sp. was the most common parasite encuntered (14.4%), followed by Blastocytis sp. (9.6%) and Giardia duodenalis (8.4%). Microsoridia was only found in the stools of one child (1.2% of total and 2% of those with diarrhea) and Enterocytozoon bieneusi was demonstrated by PCR. The patient was 10 years old, Presented non‐chronic diarrhea and his CD4 count was 298/mm3. These date differ from those previously reported by us in HIV‐positive adults (13.9%) in the same area, although this group showed more severely depressed CD4 lymphocyte counts than children. New epidemiological studies should be carried out to elucidate whether additional risk factors exist betwen these groups.
Invention and Mystery in Hypotrich DNA1
Authors: Prescott David M. 
Published: May 2007

ABSTRACT “The capacity to blunder slightly is the real marvel of DNA. Without this special attribute, we would still be anaerobic bacteria and there would be no music.” Lewis Thomas3Hypotrichs have evolved extraordinary ways of organizing, manipulating, and replicating the DNA in their micronuclear and macronuclear genomes. Short macronuclear DNA molecules containing single genes are created by excision from chromosomes, accompanied by massive elimination of the germline DNA sequences between genes. Germline genes themselves are interrupted by multiple noncoding segments called internal eliminated segments, or IESs, that divide genes into multiple macronuclear‐destined segments, or MDSs. The functional significance of this organization is unknown. Over evolutionary time IESs accumulate mutations rapidly are inserted into or excised from genes, and shift position along DNA molecules. MDSs are ligated to create functional genes when IESs are spliced out of micronuclear DNA during macronuclear development. MDSs in some germline genes are in scrambled disorder and become unscrambled in association with IES elimination. Replication of DNA in the macronucleus is accomplished by organization of replication enzymes and factors into a structure that sweeps through the macronucleus to replicate the many millions of gene‐sized DNA molecules. The significance of many of the bizarre DNA phenomena in the evolutionary/functional success of hypotrichs is still unclear.
Actin of Histriculus cavicola: Characteristics of the Highly Divergent Hypotrich Ciliate Actins1
Authors: PÉREZ‐ROMERO PILAR , VILLALOBO EDUARDO , DÍAZ‐RAMOS CORÍN , CALVO PURIFICACIÓN , TORRES ANTONIO 
Published: May 2007

ABSTRACTA macronuclear gene‐sized molecule carrying an actin gene from the hypotrich ciliate, Histriculus cavicola, was characterized. Southern blot analysis using a coding region probe suggested that actin in H. cavicola is encoded by a single gene. A comparison of the promoter regions indicated that the H. cavicola actin gene has a TATA box in the 51 flanking region in a position identical to those in other oxytrich ciliates. The coding sequence of this gene is not interrupted by any introns, and codes for a protein of 375 amino acid residues. This protein shares a high degree of similarity with other oxytrichid actins, and a relatively low similarity with actins from other eukaryotes. Comparative analyses of sequences indicated that most of the amino acid substitutions in hypotrich actins are found in surface loops, while the core structures are well‐conserved. The sites that interact with DNase I and several regions involved in actin‐actin contact have diverged considerably in hypotrich actins, while nucleotide‐binding sites are the best‐conserved interaction motif.
Ultrastructural Characterisation and Molecular Taxonomic Identification of Nosema granulosis n. sp., a Transovarially Transmitted Feminising (TTF) Microsporidium
Authors: TERRY REBECCA S. , SMITH JUDITH E. , BOUCHON DIDIER , RIGAUD THIERRY , DUNCANSON PHIL , SHARPE ROSE G. , DUNN ALISON M. 
Published: May 2007

ABSTRACTA novel microsporidian parasite is described, which infects the crustacean host Gammarus duebeni. The parasite was transovarially transmitted and feminised host offspring. The life cycle was monomorphic with three stages. Meronts were found in host embryos, juveniles, and in the gonadal tissue of adults. Sporoblasts and spores were restricted to the gonad. Sporogony was disporoblastic giving rise to paired sporoblasts, which then differentiated to form spores. Spores were not found in regular groupings and there was no interfacial envelope. Spores were approximately 3.78 × 1.22 μm and had a thin exospore wall, a short polar filament, and an unusual granular polaroplast. All life cycle stages were diplokaryotic. A region from the parasite small subunit ribosomal RNA gene was amplified and sequenced. Phylogenetic analysis based on these data places the parasite within the genus Nosema. We have named the species Nosema granulosis based on the structure of the polaroplast.
A Novel Healing Filament in Ciliate Regeneration
Authors: JERKA‐DZIADOSZ MARIA , MUSZYNSKA KATARZYNA , KRAWCZYńSKA WANDA 
Published: May 2007

ABSTRACTThe interphase cells of the hypotrich ciliate Paraurostyla weissei possess a complex fibrillar system surrounding basal bodies in the compound ciliary assemblages, cirri and membranelles. During replacement of the ciliature at cell division, transient filaments precede and accompany the development of ciliary primordia and participate in the formation of the fission furrow. Both fibrillar systems are recognized by monoclonal antibody FXXXIX 12G9. We studied regeneration of cellular fragments after transection employing the mAb 12G9 and found a new cytoskeletal structure involved in healing of the excisional wound. The healing filament is formed at the wound edge, distally and in connection with the bases of cirri closest to the wound. It is visible 5 min after transection. Concomitant with development of new ciliary primordia, the healing filament shrinks and finally disappears together with other transient fibers formed in this process. Ultrastructural analysis of immunolabeled regenerating cells revealed that structures recognized by mAbl2G9 contain fine filaments whose packing and arrangement depends on accompanying cytoplasmic elements and the developmental status of a fragment. Assembly of the healing fiber does not depend on microtubules and microfilaments since it develops in cellular fragments exposed to cold, nocodazole, and Cytochalasin D. On Western blots of whole cell and cytoskeletal extracts of P. weissei the 12G9 antibody identified one protein band whose molecular weight corresponds to 60 kDa.
Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta‐analysis
Authors: Strietzel Frank Peter , Reichart Peter A. , Kale Abhijit , Kulkarni Milind , Wegner Brigitte , Küchler Ingeborg 
Published: May 2007

AbstractAim: This systematic literature review was performed to investigate if smoking interferes with the prognosis of implants with and without accompanying augmentation procedures compared with non‐smokers.Methods: A systematic electronic and handsearch (articles published between 1989 and 2005; English and German language; search terms “dental or oral implants and smoking”; “dental or oral implants and tobacco”) was performed to identify publications providing numbers of failed implants, related to the numbers of smokers and non‐smokers for meta‐analysis. Publications providing statistically examined data of implant failures or biologic complications among smokers compared with non‐smokers were included for systematic review.Results: Of 139 publications identified, 29 were considered for meta‐analysis and 35 for systematic review. Meta‐analysis revealed a significantly enhanced risk for implant failure among smokers [implant‐related odds ratio (OR) 2.25, confidence interval (CI95%) 1.96–2.59; patient‐related OR 2.64; CI95% 1.70–4.09] compared with non‐smokers, and for smokers receiving implants with accompanying augmentation procedures (OR 3.61; CI95% 2.26–5.77, implant related). The systematic review indicated significantly enhanced risks of biologic complications among smokers. Five studies revealed no significant impact of smoking on prognosis of implants with particle‐blasted, acid‐etched or anodic oxidized surfaces.Conclusion: Smoking is a significant risk factor for dental implant therapy and augmentation procedures accompanying implantations.
Four‐year results of a prospective‐controlled clinical study evaluating healing of intra‐bony defects following treatment with an enamel matrix protein derivative alone or combined with a bioactive glass
Authors: Sculean Anton , Pietruska Malgorzata , Arweiler Nicole B. , Auschill Thorsten M. , Nemcovsky Carlos 
Published: May 2007

AbstractAim: To evaluate the 4‐year results following regenerative periodontal surgery at intra‐bony defects with either a combination of an enamel matrix protein derivative (EMD) and a bioactive glass (BG) or with EMD alone.Methods: Twenty‐five patients with one deep intra‐bony defect each were randomly treated with either an EMD+BG (test) or with EMD alone (control). Measurements were recorded at baseline, at 1 and at 4 years following therapy. The primary outcome variable was the clinical attachment level (CAL).Results: The test group demonstrated a mean CAL change from 10.3±1.6 to 6.7±1.2 mm (p<0.001) and to 6.9±1.0 mm (p<0.001) at 1 and 4 years, respectively. No statistically significant differences were found between the 1‐ and 4‐year results. The control group showed a mean CAL change from 10.4±1.6 to 6.7±1.1 mm (p<0.001) at 1 year and 7.0±0.9 mm (p<0.001) at 4 years. The CAL change between 1 and 4 years did not present statistically significant differences. In each of the two groups, four defects have lost 1 mm of the CAL gained at 1 year. A CAL gain of 1 mm compared with the 1‐year results was measured in only one defect of the test group. Compared with baseline, a CAL gain of 3 mm was found at 4 years in 10 defects in both groups.Between the treatment groups, no statistically significant differences in any of the investigated parameters were observed at 1 and at 4 years.Conclusions: Within their limits, the present results indicate that the clinical improvements obtained with both regenerative modalities can be maintained over a period of 4 years.