Lutzomyia longipalpis salivary gland homogenate impairs cytokine production and costimulatory molecule expression on human monocytes and dendritic cells

In this report, we describe an investigation of the effects of Lutzomyia longipalpis sand fly salivary gland homogenates (SGH) on cytokine production and expression of costimulatory molecules on human monocytes, macrophages (Ms), and dendritic cells (DCs). SGH of L. longipalpis induced an increase in interleukin-6 (IL-6), IL-8 and IL-12p40 production but a decrease in tumor necrosis factor alpha and IL-10 production by lipopolysaccharida (LPS)-stimulated monocytes. We also examined the expression of costimulatory molecules on the surface of monocytes, Ms, and DCs. Whereas SGH affected the expression of these molecules on monocytes and Ms, it had little effect on these molecules on DCs. However, when DCs were generated from human monocytes in the presence of SGH, SGH inhibited the expression of costimulatory molecules. In addition, a decrease in the maturation of DCs induced by CD40L was observed in the presence of SGH. Finally, preincubating SGH with human sera containing anti-SGH-specific antibodies abolished the effects of SGH on cytokine production by LPS-stimulated monocytes.     

Induction of ribonucleotide reductase activity in cells infected with African swine fever virus.

Infection of Vero cells with African swine fever virus (ASFV) resulted in a marked increase in ribonucleotide reductase activity. The induction of ribonucleotide reductase was detected early after infection and was proportional to the multiplicity of infection. Inhibition of viral DNA replication did not affect the induction of the enzyme. Several characteristics could distinguish the virus-induced from the normal cell enzyme. ASFV-induced ribonucleotide reductase was inhibited by magnesium, was more strongly inhibited by hydroxyurea, and had a fourfold lower Km. The virus-induced enzyme was inhibited by deoxyribonucleoside triphosphates and by ATP. The isolation of hydroxyurea-resistant ASFV mutants provided genetic evidence for the viral origin of the induced ribonucleotide reductase. The resistance to hydroxyurea was due to a threefold overproduction of ribonucleotide reductase, as compared to enzyme induction by wild-type ASFV. Hydroxyurea had similar effect in vitro on ribonucleotide reductases induced by wild-type or mutant virus. The gene for the small subunit of the viral enzyme was mapped within a 2.3-kb fragment by hybridization with an oligonucleotide probe designed from a conserved aminoacid sequence of eukaryotic and viral ribonucleotide reductases.     

Distribution and viral load of type specific HPVs in different cervical lesions as detected by PCR-ELISA

AIMS: To investigate the distribution and viral load of the most prevalent high risk human papillomavirus (HPV) types 16, 18, 31, 33, and 45 and low risk HPV types 6 and 11 in a variety of cervical lesions. METHODS: One hundred and seventy six cytological specimens from women with different cervical lesions were investigated. For an accurate standardisation of the sample, cervical cells were counted and a volume of the cell suspension processed by polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA). Semiquantitative determinations were achieved in relation to an external reference titration curve. RESULTS: HPV DNA was detected in 60.2% of the samples. HPV-16 was the prevalent genotype (57.6%), followed by HPV-33, HPV-31, HPV-6, HPV-18, and HPV-45. HPV-11 was not detected. HPV-16 showed a pronounced increase in prevalence with the evolution of cervical disease. Semiquantitative evaluation of the results showed that only HPV-16 DNA could reach very high values (> 1000 genome copies/cell) and a very high HPV-16 load correlated with the severity of cervical disease. CONCLUSIONS: Only HPV-16 load appears to be associated with the severity of cervical disease.     

Bone marrow and peripheral blood globin chain synthesis in sickle cell beta zero thalassaemia.

A similar imbalance of globin chain synthesis, with low non-alpha/alpha ratios, was shown in peripheral blood and in bone marrow of compound heterozygotes for both the Hb S and beta zero thalassaemia genes (S/beta zero thalassaemia). Previous purification of whole cell globin obtained from the bone marrow did not change the non-alpha/alpha ratio. The mean non-alpha/alpha ratios were 0.57 +/- 0.13 (means +/- SD) for the peripheral blood of 12 patients, 0.52 +/- 0.10 for five patients using bone marrow globin purified on Sephadex G100, and 0.55 +/- 0.16 for the unfiltered bone marrow globin of five patients. The data show that patients with S/beta zero thalassaemia have a similar beta chain deficiency in reticulocytes and in bone marrow cells, provided whole cell globin is used which avoids the removal of the free alpha chains. The non-alpha/alpha ratios in the peripheral blood of an S/beta zero thalassaemia patient and a beta thalassaemia heterozygote from the same family were compared in seven families and no significant difference was found.     

Treatment of metastatic malignant melanoma with dacarbazine plus tamoxifen.

BACKGROUND. Endocrine factors may affect the clinical course of malignant melanoma and the response to the treatment of this disease. The presence of estrogen receptors in melanomas has been suggested, and occasional responses to antiestrogen therapy have been reported. METHODS AND RESULTS. We randomly assigned 117 patients with metastatic malignant melanoma to treatment with dacarbazine alone or dacarbazine in combination with tamoxifen. The overall rate of response, measured objectively, was higher (28 percent vs. 12 percent, P = 0.03) and survival was longer (median, 48 vs. 29 weeks, P = 0.02) among the patients who received dacarbazine plus tamoxifen than among those who received dacarbazine alone. Among women, both the response rate (38 percent vs. 10 percent, P = 0.04) and the median survival (69 vs. 30 weeks, P = 0.008) were better with dacarbazine plus tamoxifen than with dacarbazine alone, whereas among men the differences were smaller and not statistically significant. Among the patients given dacarbazine alone, there were no significant differences between women and men in response rate (10 percent vs. 13 percent) or survival (30 vs. 27 weeks), whereas among those given dacarbazine plus tamoxifen, women had better outcomes, as indicated by both response rate (38 percent vs. 19 percent, P = 0.15) and survival (69 vs. 31 weeks, P = 0.02). When we analyzed the Quetelet body-mass index (the weight in kilograms divided by the square of the height in meters) as an indirect indicator of the levels of endogenous estrogens in postmenopausal women and in men, survival was not affected by the body-mass index in the group given dacarbazine alone, whereas in the group given dacarbazine plus tamoxifen, survival was longer among patients whose Quetelet index was above the median value than among those with a Quetelet index lower than the median value (60 vs. 26 weeks, P less than 0.001). CONCLUSIONS. In the treatment of metastatic malignant melanoma, dacarbazine plus tamoxifen is more effective than dacarbazine alone, as indicated by both the response rate and the median survival; the difference in efficacy is among women.     

Utilization of indole compounds by Cryptococcus neoformans to produce a melanin-like pigment

Several indoles served as substrates for the phenoloxidase of Cryptococcus neoformans and resulted in the production of a melanin-like pigment. In general, a higher percentage of C. neoformans var. neoformans (A and D serotypes) isolates could produce pigment from indoles than could those of var. gattii (B and C serotypes). Only compounds with a hydroxyl or an amino group on the phenyl ring produced pigment; methoxy, nitro, methyl, and fluorine substituents on the phenyl ring were inactive, as was a hydroxyl group at the 2 position on the indole ring. The phenoloxidase of C. neoformans thus appears to differ from that found in Mycobacterium leprae, which cannot use a hydroxyindole, desoxyfructo-5-hydroxytryptamine, as a substrate. In addition, C. neoformans differs from M. leprae in that desoxyfructo-5-hydroxytryptamine does not inhibit the uptake of dihydroxyphenylalanine into the cell.     

Recombinant cysteine proteinase from Leishmania (Leishmania) chagasi implicated in human and dog T-cell responses

High in vitro lymphoproliferative responses were induced in humans and dogs by a recombinant Leishmania (Leishmania) chagasi cysteine proteinase, with secretion of IFN-gamma in asymptomatic subjects or of IFN-gamma, interleukin 4 (IL-4), and IL-10 in oligosymptomatic subjects. In contrast, responses of symptomatic patients and dogs were lower, with production of IL-4 and IL-10.     

Physiological response and childhood anxiety: association with symptoms of anxiety disorders and cognitive bias.

This study examined the physiological response (skin conductance and heart rate [HR]) of youth exposed to a mildly phobic stimulus (video of a large dog) and its relation to child- and parent-reported anxiety symptoms and cognitive bias in a community-recruited sample of youth (n = 49). The results of this study indicated that HR and skin-conductance response were associated with youth report but not parent report of their child's symptoms of anxiety disorders and that HR response was more strongly associated with anxiety symptoms than skin-conductance response. Physiological response was uniquely associated with youth-reported symptoms of anxiety rather than youth-reported depression. Finally, HR response interacted with cognitive bias in predicting childhood anxiety disorder symptoms in a manner consistent with theories of the etiology of anxiety disorders.     

Paraganglioma of the spermatic cord. Report of a case with immunohistochemical and ultrastructural studies

We describe a case of paraganglioma arising in the spermatic cord, which is an extremely rare location. Immunohistochemical studies characterized two types of cells: (1) polygonal cells expressing neuron-specific enolase, chromogranin A, and synaptophysin and (2) S100 protein-positive sustentacular cells. Electron microscopy revealed that within the cytoplasm of the polygonal cells, there were electron-dense granules whose morphological appearance was consistent with that of neurosecretory granules. Paraganglioma of the spermatic cord may originate from embryonic chromaffin cells that have followed the testis into the scrotum.     

The Helix aspersa (brown garden snail) allergen repertoire

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed. RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail. CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.