Fine needle aspiration of retroperitoneal human dirofilariasis with a pseudotumoral presentation

The accidental finding of a pseudotumoral para-aortic mass in a 60-year-old woman led to the performance of a fine needle aspiration (FNA) biopsy under ultrasonographic guidance. The milky aspirate was centrifuged and processed as a cell block. The examination of sections confirmed the lymphatic origin of the sample, but also revealed some unexpected parasitic structures. While a complete identification could not be made on a few sections, the morphologic and epidemiologic evidence suggested Dirofilaria repens. The mass was surgically removed and identified as an adenolymphocele, which appears to be a new localization of dirofilariasis in humans. This case emphasizes the utility of FNA in diagnosing such unexpected findings without the use for exploratory surgery.     

Proteinases and amylases of larval midgut of Zabrotes subfasciatus reared on cowpea (Vigna unguiculata) seeds

Proteinase and amylase activities in larval midguts of the bruchid beetle Zabrotes subfasciatus (Boh.) (Coleoptera: Bruchidae) reared on cowpea (Vigna unguiculata (L.) Walp.) seeds were investigated. We could detect and isolate a proteolytic activity with a pH optimum of 5.5 (on azo-casein as substrate) which was activated by thiol reagents and inhibited by several compounds reactive against-SH groups. None of the plant protein inhibitors of serine proteinases utilized were effective inhibitors of this activity. This activity has characteristics of a cysteine class proteinase. We could also detect and isolate a proteolytic activity with a pH optimum of 3.5 (on hemoglobin as substrate) which was not influenced by activators or inhibitors of cysteine, serine, or metalloproteinases. This activity was totally inhibited by pepstatin, a specific inhibitor of aspartic proteinases. We conclude that this activity is due to an aspartic class proteinase. We found also that the aspartic class proteolytic activity is higher than the cysteine class proteinase activity in the midguts of Z. subfasciatus. This seems to be contrary to what is found in Callosobruchus maculatus (F.) larvae midguts. An amylolytic activity with the charateristics of an -amylase was also detected and isolated.

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Résumé Les activités protéinase et amylase ont été étudiées sur l'intestin moyen de larves de Zabrotes subfasciatus Boh. (Coléo, Bruchidae), élevées sur graines de Vigna unguiculata Walp. Nous avons pu déceler et isoler une activité protéolytique optimale à pH 5,5 (sur substrat d'azo-caséine) activée par des réactifs thiol et inhibée par plusieurs composés réagissant aux groupements SH. Aucun inhibiteur végétal des sérine-protéases utilisé n'a inibé efficacement cette activité qui présente les caractéristiques des protéines de la famille des cystéines. Nous avons pu déceler et isoler aussi une activité protéolytique optimale au pH 3,5 (sur hémoglobine comme substrat) qui n'était pas modifiée par les activateurs ou les inhibiteurs de cystéine, de sérine ou de métalloprotéinases. Cette activité était totalement inhibée par la pepstatine, inhibiteur spécifique des protéinases aspartiques. Nous en concluons que l'activité est due à une protéinase de la famille aspartique. Nous avons trouvé aussi que l'activité protéolytique de la famille aspartique était supérieure à l'activité protéinase de la famille cystéine dans l'intestin moyen de Z. subfasciatus. Ceci semble l'inverse de ce qui a été observé dans l'intestin moyen des larves de Callosobruchus maculatus F. (C.P. Silva & al, in litt.). Une activité amylolytique ayant les caractéristiques d'une -amylase a aussi été décelée.

     

Production rates of prostaglandin F, 6-keto-PGF1α and thromboxane B2 by perifused human endometrium

Human endometrium obtained from fresh hysterectomy specimens was perifused for 7 hr in 95% O₂/5% CO₂ at 37°C. The phase of the menstrual cycle was determined by histological examination. The concentrations of PGF, 6-keto-PGF_1α and TxB₂ in 20 min fractions of the perifusion medium were measured by radioimmunoassay and production rates were calculated in terms of dry weight of tissue. Biphasic patterns of production were observed; high initial values fell to about 20% at 2 hr and then increased to relatively stable values at about 4 hr which were maintained for the next 2 hr. During this latter period, production rates in endometria taken at different phases of the cycle differed markedly from each other; the production rates of PGF in secretory and early proliferative endometria were low (15.8 ± 2.6, mean ± SEM and 67.2 ± 8.3 ng/min/g respectively) whereas they were high in late proliferative and premenstrual endometria (188.0 ± 16.7 and 196.4 ± 16.9 ng/min/g respectively). The patterns of production of 6-keto-PGF_1α and TxB₂ were similar to those of PGF but the absolute values were much lower (<10%). We conclude that the observed rates of production of prostaglandins by perifused human endometrium are consistent with synthesis being stimulated either by estrogen or withdrawal of hormonal support and being inhibited by progesterone.     

The effect of clupeinon anisotropy and basophilia of polytene chromosomes

Summary When polytene chromosomes are subjected to a clupein treatment, their properties of basophilia and anisotropy are affected. The basophilia is deeply reduced, except in the nucleolar zones, puffs and sites of RNA accumulation. On the other hand, the chromosome birefringence increases. The phenomenon of anomalous dispersion of birefringence usually observed on polytene chromosomes stained with toluidine blue solutions turns into a normal negative dispersion of birefringence, when staining is preceded by clupein treatment. It is concluded that the clupein molecules attach orderly and preferentially to sequential DNA phosphates unbound to chromosome proteins, accentuating DNA anisotropic characteristics. The clupein molecules appear not attaching to RNA phosphates.     

On the identity of dnaP and dnaF genes of Bacillus subtilis

Summary The dnaP strains of Bacillus subtilis are altered in the initiation of DNA replication at high temperature (Riva et al., 1975). Fine mapping of the gene shows that it is located very close to the dnaF gene, described by Karamata and Gross (1970) and mapped by Love et al. (1976) in the polC region. The phenotype of both mutants is indistinguishable: the DNA synthesis stops at non permissive temperature after synthesizing an amount of DNA equivalent to the completion of the rounds of replication already initiated; at permissive temperature they are abnormally sensitive to MMS and are reduced in the ability to be transformed. Both mutants are to be considered as belonging to the dnaF locus.The dnaF gene is very close to the polC gene, which specifies the DNA polymerase III of B. subtilis. The DNA polymerase III of the dnaF mutants is not temperature sensitive in vitro, however, the level of this enzyme is lower by a factor of 4 or 5 in the dnaF mutants, at the permissive temperature. Following shift of dnaF cultures to the non permissive temperature, the level of DNA polymerase III activity specifically decreases further by a factor of at least 10 in the mutant, whereas the DNA polymerase I level is unaffected.The possible roles of the dnaF gene in the control of the cellular level of the DNA polymerase III, and the possibility of a regulatory role of DNA polymerase III in the initiation of DNA replication in bacteria are discussed.Abbreviations and symbols HPUra 6-(p-hydroxyphenylazo)-uracil; mic, minimum inhibitory concentration - MMS methyl-methanesufonate - Pol I Pol II and Pol III: DNA polymerase I, II and III respectively - PCMB parachloro-mercuri-benzoate     

Acridinium ester conjugated to lectin as chemiluminescent histochemistry marker

Abstract

Cell differentiation/dedifferentiation includes changes in oligosaccharide composition and distribution in the cell surface glycoconjugates. Lectins have been used as auxiliary tools in histopathological diagnosis of mammary, uterus and brain pathologies. Acridinium ester (AE) conjugated to biomolecules has been employed in chemiluminescent analytical applications. This work aimed to use a lectin, concanavalin A (Con A), conjugated to AE as a chemiluminescent histochemistry tool. Biopsies of normal and infiltrating duct carcinoma (IDC) of mammary tissues were treated by a Con A–AE derivative. Photon emission, observed during the breakage of the chemical bound between Con A and AE, was quantified, expressed in relative light units (RLU) and correlated to the labelling of the normal and transformed tissues. The results demonstrated that RLU presented a linear relationship with the labelled tissue area in the range 0.125–1.0?cm² (r=0.98). Furthermore, RLU was much higher for the IDC (1283.920×10³±220.621×10³) than the normal tissue (2.565×10³±0.247×10³), namely, about 500 times higher. The Con A–AE conjugation efficiency, differential staining of normal and IDC tissues, and quantification of results contribute to a decrease in the subjectivity in routine histopathological diagnoses and indicate that acrydinum ester can join other lectin marker to be used in histochemistry.     

Effects of flask sealing and growth regulators on in vitro propagation of neem (Azadirachta indica A. Juss.)

In vitro propagation of neem (Azadirachta indica A. Juss.) may offer an efficient alternative to seed propagation of this species. For optimization of in vitro propagation, different basal salt formulations, growth regulators, and culture container sealants (polytetrafluoroethylene hydrophobic membranes [PTFE]) were evaluated. Nodal segments cultured on Murashige and Skoog (MS) medium showed the highest shoot formation per explant (1.67). Explants cultured in flasks containing MS medium with 0.5 mg L⁻¹ benzyladenine, 0.5 mg L⁻¹ kinetin, and 0.05 mg L⁻¹ naphthaleneacetic acid, and sealed with two PTFE membranes, produced the highest number of shoots (4.04). In contrast, explants cultured in flasks without membranes showed leaf chlorosis and senescence. For plant recovery, regenerants were acclimatized in a substrate of coconut fiber and eucalyptus bark (1:1) and showed 80% survival. Our results indicated that the use of flasks with vents was beneficial for in vitro propagation of this important plant.     

Vesicular trafficking permits evasion of cGAS/STING surveillance during initial human papillomavirus infection

Oncogenic human papillomaviruses (HPVs) replicate in differentiating epithelium, causing 5% of cancers worldwide. Like most other DNA viruses, HPV infection initiates after trafficking viral genome (vDNA) to host cell nuclei. Cells possess innate surveillance pathways to detect microbial components or physiological stresses often associated with microbial infections. One of these pathways, cGAS/STING, induces IRF3-dependent antiviral interferon (IFN) responses upon detection of cytosolic DNA. Virion-associated vDNA can activate cGAS/STING during initial viral entry and uncoating/trafficking, and thus cGAS/STING is an obstacle to many DNA viruses. HPV has a unique vesicular trafficking pathway compared to many other DNA viruses. As the capsid uncoats within acidic endosomal compartments, minor capsid protein L2 protrudes across vesicular membranes to facilitate transport of vDNA to the Golgi. L2/vDNA resides within the Golgi lumen until G2/M, whereupon vesicular L2/vDNA traffics along spindle microtubules, tethering to chromosomes to access daughter cell nuclei. L2/vDNA-containing vesicles likely remain intact until G1, following nuclear envelope reformation. We hypothesize that this unique vesicular trafficking protects HPV from cGAS/STING surveillance. Here, we investigate cGAS/STING responses to HPV infection. DNA transfection resulted in acute cGAS/STING activation and downstream IFN responses. In contrast, HPV infection elicited minimal cGAS/STING and IFN responses. To determine the role of vesicular trafficking in cGAS/STING evasion, we forced premature viral penetration of vesicular membranes with membrane-perturbing cationic lipids. Such treatment renders a non-infectious trafficking-defective mutant HPV infectious, yet susceptible to cGAS/STING detection. Overall, HPV evades cGAS/STING by its unique subcellular trafficking, a property that may contribute to establishment of infection.