Fine needle aspiration cytology of lymph nodes in HIV-infected individuals

OBJECTIVE: To assess the role of fine needle aspiration cytology (FNAC) in lymphadenopathy in human immunodeficiency virus-infected individuals (HIVII). STUDY DESIGN: Thirty-nine HIVII presenting with lymphadenopathy at University Hospital, Kuala Lumpur, were subjected to FNAC. Cytologic smears were routinely stained with May-Grünwald-Giemsa stain. Special stains and immunostains were used when necessary. RESULTS: In nine cases, the cytologic appearance was compatible with HIV type A and in one case with HIV type C lymphadenopathy. In 21 cases, acid-fast bacilli (AFB) were demonstrated in the cytologic smears, enabling a diagnosis of mycobacterial lymphadenitis. In one of these cases there was a concomitant infection with Penicillium marneffei that was overlooked on initial cytologic examination. The cause of granulomatous lymphadenitis could not be ascertained in one case, where neither AFB nor any other organisms were demonstrable. Two cases of histoplasma and one of cryptococcal lymphadenitis were diagnosed, as was one high grade non-Hodgkin's lymphoma that could be immunophenotyped on cytologic material. In three cases the aspirates were inadequate for a cytologic diagnosis. CONCLUSION: Lymph node FNAC is a valuable investigative modality in HIVII. Most opportunistic infections (bacterial and fungal) can be correctly identified, and high grade lymphoma can be diagnosed and phenotyped.     

Gust J, a salt-insensitive mutant ofDrosophila melanogaster

A set of 340 P insert lines on the X chromosome and the autosomes were screened for altered responses of the labellar chemoreceptors to salts and sucrose. A mutant linegustJ was isolated in which the electrophysiological response of the salt-sensitive neuron to Na⁺ in the sensilla of the proboscis is reduced. The responses to KC1 and sucrose are unaffected. In feeding tests,gustJ flies have Na⁺-specific defects. Heterozygotes ofgustJ with two other salt mutantsgustE andBE1323 are normal. Multiple alleles ofgustJ have been obtained by excision of the original P element. All mutants have defects in Na⁺ sensing specifically, thus defining a new gene that affects Na⁺ response of the fly.     

Cytology of hemangioendothelioma

The cytologic appearance is described of hemangioendothelioma in fine needle aspiration smears from a young male who presented with recurring bilateral lesions within two years. The cytomorphologic pattern was extremely cellular, with a monomorphic population of cells, some of which showed a tendency to form rosettelike or pseudoacinar formations.     

Aqueous Hydration of Nucleic Acid Constituents: Monte Carlo Computer Simulation Studies

Abstract

Monte Carlo computer simulations were performed on dilute aqueous solutions of thymine, cytosine, uracil, adenine, guanine, the dimethyl phosphate anion in the gauche-gauche conformation and a ribose and deoxyribose derivative. The aqueous hydration of each molecule was analysed in terms of quasi-component distribution functions based on the Proximity Criterion, and partitioned into hydrophobic, hydrophilic and ionic contributions. Color stereo views of selected hydration complexes are also presented. A preliminary discussion of the transferability of functional group coordination numbers is given. The results enable to comment on two current problems related to the hydration of nucleic acids: a) the theory of Dickerson and coworkers on the role of water in the relative stability of the A and B forms of DNA and b) the idea of water bridges and filaments emerging from the computer simulation results on the hydration of DNA fragments by Clementi.     

Effect of vitamin A nutritional status on the ribonucleic acids of liver, intestinal mucosa and testes of rats.

1. Vitamin A deficiency led to an increase in the oligonucleotide fraction of testes and intestinal mucosa of rats at the expense of high-molecular-weight RNA and 4S RNA, but no such changes were observed in the liver. Retinyl acetate supplementation reversed these effects in both tissues, whereas retinoic acid supplementation was almost equally effective in the mucosa but virtually ineffective in the testes. The ribonuclease activities of all the tissues remained unaffected by the above treatments. 2. The effect of vitamin A deprivation on the acceptor activity of the tRNA of the testes and intestinal mucosa was more pronounced than on the liver tRNA. The testes and mucosal tRNA of the retinoic acid-supplemented rats showed significantly lower charging capacity as compared with the retinyl acetate-supplemented ones. Here also no significant effect was observed on the liver tRNA. 3. Vitamin A deficiency caused a decrease in the percentage of poly(A) in RNA of the mucosa and testes, but not in the liver RNA. The poly(A) contents of both tissues were brought to normal by retinyl acetate supplementation; treatment with retinoic acid led to an appreciable increase in poly(A) in the mucosa, but considerably less increase in poly(A) in the testes. 4. The incorporation of H332PO4 into the rRNA and tRNA of the testes was lowered by vitamin A deficiency, but no such effects was observed in the liver RNA.     

Phytochemicals of Salacia oblonga responsible for free radical scavenging and antiproliferative activity against breast cancer cell lines (MDA-MB-231)

Salacia oblonga, an inhabitant of tropical regions has been used in traditional Indian medicinal systems. Phytochemicals were extracted in methanol from the plant and analyzed for various biological activities. The results of biochemical tests for total phenolics (297 ± 0.005 and 275 ± 0.006) and flavonoids (95 ± 0.004 and 61.6 ± 0.004) in the aerial and root parts were indicated as Gallic acid and quercetin equivalents respectively. The Aerial and root extracts showed strong reducing ability based on reducing power and FRAP assays. The extracts exhibited significant IC₅₀ values in DPPH, super oxide and nitric oxide radical scavenging assays. The extracts displayed low IC₅₀ values (<50 μg/ml) when assessed for antiproliferative activity against breast cancer cell lines using the MTT assay. GC-MS analysis of methanolic extracts have revealed the presence of compounds viz. n-Hexadecanoic acid, N-Methoxy-N-methylacetamide, Ursa-9(11), 12-dien-3-ol, Gamma-sitosterol etc., that might be potential candidates for the biological activity exhibited by the extract.

Electronic supplementary material

The online version of this article (doi:10.1007/s12298-015-0317-z) contains supplementary material, which is available to authorized users.Keyword: Salacia oblonga, Antioxidant activity, Free radical scavenging activity, Reactive oxygen species, Antiproliferative activity     

Stereospecific suppression of active site mutants by methylphosphonate substituted substrates reveals the stereochemical course of site-specific DNA recombination

Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modification. The chemical chirality of MeP, in conjunction with mutant recombinases, reveals the stereochemical contributions of Arg-I and Arg-II. The S_P preference of the native reaction is specified primarily by Arg-I. MeP reaction supported by Arg-II is nearly bias-free or R_P-biased, depending on the Arg-I substituent. Positional conservation of the arginines does not translate into strict functional conservation. Charge reversal by glutamic acid substitution at Arg-I or Arg-II has opposite effects on Cre and Flp in MeP reactions. In Flp, the base immediately 5′ to the scissile MeP strongly influences the choice between the catalytic tyrosine and water as the nucleophile for strand scission, thus between productive recombination and futile hydrolysis. The recombinase active site embodies the evolutionary optimization of interactions that not only favor the normal reaction but also proscribe antithetical side reactions.     

Chk2 and P53 Regulate the Transmission of Healed Chromosomes in the Drosophila Male Germline

When a dicentric chromosome breaks in mitosis, the broken ends cannot be repaired by normal mechanisms that join two broken ends since each end is in a separate daughter cell. However, in the male germline of Drosophila melanogaster, a broken end may be healed by de novo telomere addition. We find that Chk2 (encoded by lok) and P53, major mediators of the DNA damage response, have strong and opposite influences on the transmission of broken-and-healed chromosomes: lok mutants exhibit a large increase in the recovery of healed chromosomes relative to wildtype control males, but p53 mutants show a strong reduction. This contrasts with the soma, where mutations in lok and p53 have the nearly identical effect of allowing survival and proliferation of cells with irreparable DNA damage. Examination of testes revealed a transient depletion of germline cells after dicentric chromosome induction in the wildtype controls, and further showed that P53 is required for the germline to recover. Although lok mutant males transmit healed chromosomes at a high rate, broken chromosome ends can also persist through spermatogonial divisions without healing in lok mutants, giving rise to frequent dicentric bridges in Meiosis II. Cytological and genetic analyses show that spermatid nuclei derived from such meiotic divisions are eliminated during spermiogenesis, resulting in strong meiotic drive. We conclude that the primary responsibility for maintaining genome integrity in the male germline lies with Chk2, and that P53 is required to reconstitute the germline when cells are eliminated owing to unrepaired DNA damage.     

Independent Adipogenic and Contractile Properties of Fibroblasts in Graves’ Orbitopathy: An In Vitro Model for the Evaluation of Treatments

Graves’ orbitopathy (GO) is a disfiguring and sometimes blinding disease, characterised by inflammation and swelling of orbital tissues, with fibrosis and adipogenesis being predominant features. Little is known about the disease aetiology and the molecular mechanisms driving the phenotypic changes in orbital fibroblasts are unknown. Using fibroblasts isolated from the orbital fat of undiseased individuals or GO patients, we have established a novel in vitro model to evaluate the dual profile of GO cells in a three-dimensional collagen matrix; this pseudo-physiological 3D environment allows measurement of their contractile and adipogenic properties. GO cells contracted collagen matrices more efficiently than control cells following serum or TGFβ1 stimulation, and showed a slightly increased ability to proliferate in the 3D matrix, in accordance with a fibro-proliferative phenotype. GO cells, unlike controls, also spontaneously differentiated into adipocytes in 3D cultures - confirming an intrinsic adipogenic profile. However, both control and GO cells underwent adipogenesis when cultured under pathological pressure levels. We further demonstrate that a Thy-1-low population of GO cells underlies the adipogenic - but not the contractile - phenotype and, using inhibitors, confirm that the contractile and adipogenic phenotypes are regulated by separate pathways. In view of the current lack of suitable treatment for GO, we propose that this new model testing the duality of the GO phenotype could be useful as a preclinical evaluation for the efficacy of potential treatments.     

Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events

The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs) and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR). These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.