Antimicrobial activities of novel bipyridine compounds produced by a new strain of Saccharothrix isolated from Saharan soil

The actinobacterium strain ABH26 closely related to Saccharothrix xinjiangensis, isolated from an Algerian Saharan soil sample, exhibited highly antagonist activity against Gram-positive bacteria, yeasts and filamentous fungi. Its ability to produce antimicrobial compounds was investigated using several solid culture media. The highest antimicrobial activity was obtained on Bennett medium. The antibiotics secreted by strain ABH26 on Bennett medium were extracted by methanol and purified by reverse-phase HPLC using a C18 column. The chemical structures of the compounds were determined after spectroscopic (¹H NMR, ¹³C NMR, ¹H-¹H COSY and ¹H-¹³C HMBC spectra), and spectrometric (mass spectrum) analyses. Two new cyanogriside antibiotics named cyanogriside I (1) and cyanogriside J (2), were characterized along with three known caerulomycins, caerulomycin A (3), caerulomycin F (4) and caerulomycinonitrile (5). This is the first report of cyanogrisides and caerulomycins production by a member of the Saccharothrix genus. The minimum inhibitory concentrations (MIC) of these antibiotics were determined against pathogenic microorganisms.     

Pleural flap to prevent lobar torsion: a novel technique

Lobar torsion is reported as very rare but sometimes catastrophic complication if overlooked during the early postoperative period following a lobectomy, though it is totally preventable. In this novel technique, a piece of parietal pleural flap is harvested from the posterior wall of the chest using a hook diathermy while keeping its upper border as close to the apex as possible. Finally, distal end of the flap is secured to the upper edge of the lobe using a fine monofilament absorbable suture. This procedure not only protects the lobe from rotation but also maintains continuous expansion of the lung in the early postoperative period and may, therefore, be a good option to prevent such a serious complication in selected patients following a lobectomy.     

Erythropoietin stimulates wound healing and angiogenesis in mice.

Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, malondialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area.     

The role of mast cells and histamine in leukocyte-endothelium interactions in four rat strains

 The objective of the present study was to determine the role of mast cells and histamine in leukocyte-endothelium interactions in mesenteric venules of four rat strains: Brown Norway, Lewis, Sprague-Dawley and Wistar. Intravital microscopy showed that the mast cell stabilizer cromoglycate (5 mg/kg i.v. just before exteriorization of the mesentery) did not affect the baseline level and velocity of leukocyte rolling in any of the four strains. This finding is in agreement with the observation that cromoglycate pretreatment only slightly influenced mast cell degranulation in all strains except the Brown Norway. After mast cell stabilization, only in Sprague-Dawley did topical administration of histamine (10^–4 M) result in a significant increase in the level of leukocyte rolling and a decrease in the rolling velocity compared with the time control. Histamine induced leukocyte adhesion only in the Brown Norway strain. In conclusion, the hypothesis presented in other studies, that degranulation of mast cells, and more specifically the release of histamine, is of major importance for the induction of leukocyte-endothelium interactions in rat mesenteric venules is not generally applicable; the present study shows a clear strain dependency. Received: 18 July 1997 / Received after revision: 17 November 1997 / Accepted: 13 March 1998     

Re-redo cervical mediastinoscopy for a recurrent lung cancer

Indian Journal of Thoracic and Cardiovascular Surgery -     

Ceruloplasmin level in women with breast disease. Preliminary results.

The average ceruloplasmin levels of 29 patients with active breast cancer and 22 patients in remission were 824 +/- 61 mg/l and 630 +/- 18 mg/l respectively. The average ceruloplasmin level of 17 patients with benign breast diseases was 555 +/- 29 mg/l and of 18 healthy women in a control group 584 +/- 17 mg/l. Breast cancer patients not in remission had ceruloplasmin levels which were significantly increased when compared to the other 3 groups. The CA 15-3 levels and ceruloplasmin levels were positively correlated. We propose that ceruloplasmin may be used as a tumour marker in the follow-up of patients with breast cancer.     

Immunopathogenesis of infection with the visceralizing Leishmania species

Human leishmaniasis is a spectral disease that includes asymptomatic self-resolving infection, localized skin lesions, and progressive visceral leishmaniasis. With some overlap, visceral and cutaneous leishmaniasis are usually caused by different species of Leishmania. This review focuses on host responses to infection with the species that cause visceral leishmaniasis, as they contrast with species causing localized cutaneous leishmaniasis. Data from experimental models document significant differences between host responses to organisms causing these diverse syndromes. The visceralizing Leishmania spp. cause localized organ-specific immune responses that are important determinants of disease outcome. Both the Leishmania species causing cutaneous and those causing visceral leishmaniasis require a Type 1 immune response to undergo cure in mouse models. However, during progressive murine infection with the visceralizing Leishmania sp., the Type 1 response is suppressed at least in part by TGF-beta and IL-10 without type 2 cytokine production. This contrasts with the cutaneous species L. major, in which a Type 2 response suppresses type 1 cytokines and leads to murine disease progression. Population and family studies are beginning to elucidate human genetic determinants predisposing to different outcomes of Leishmania infection. These studies should eventually result in a better understanding of the immunopathogenesis and the spectrum of human leishmaniasis.     

Neurodynamic Studies on Emotional and Inverted Faces in an Oddball Paradigm

The detection of a change in a face stimulus was studied in an oddball paradigm. Event-related potentials (ERPs) and MEG responses to face stimuli were recorded in four conditions: 1) happy standard, neutral deviant; 2) neutral standard, neutral deviant; 3) inverted happy standard, inverted neutral deviant; 4) inverted neutral standard, inverted neutral deviant. In all conditions, the target was a face with glasses. Neutral deviants elicited a negative deflection (with a maximum around 280 ms) in ERP and MEG responses, an effect similar to auditory mismatch negativity. Face inversion diminished deviance-related negativity, implying an important role of face recognition in the observed effect. Emotional content and larger physical differences between stimuli in conditions 1 and 3 compared to conditions 2 and 4 did not show statistically significant effect on the neutral-deviant-related negativity.     

Rheumatic heart disease: proinflammatory cytokines play a role in the progression and maintenance of valvular lesions

Heart lesions of rheumatic heart disease (RHD) patients contain T-cell clones that recognize heart proteins and streptococcal M peptides. To functionally characterize heart-infiltrating T lymphocytes, we evaluated their cytokine profile, both directly in situ and in T-cell lines derived from the heart (HIL). Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-10 expressions were characterized in 20 heart tissue infiltrates from 14 RHD patients by immunohistochemistry. IFN-gamma-, TNF-alpha-, and IL-10-positive cells were consistently predominant, whereas IL-4 was scarce in the valves. In agreement with these data, the in vitro experiments, in which 13 HILs derived from heart samples of eight patients were stimulated with M5 protein and the immunodominant M5 (81-96) peptide, IL-4 was detected in HIL derived from the atrium (three of six) but not from the valve (zero of seven). IFN-gamma and IL-10 production were detected in culture supernatants in 11 of 13 and 6 of 12 HILs, respectively. The predominant IFN-gamma and TNF-alpha expression in the heart suggests that Th1-type cytokines could mediate RHD. Unlike in reversible myocardium inflammation, the significantly lower IL-4 expression in the valvular tissue (P = 0.02) may contribute to the progression of the RHD leading to permanent valvular damage (relative risk, 4.3; odds ratio, 15.8). The lack of IL-4 in vitro production by valve-derived HIL also emphasizes the more severe tissue destruction in valves observed in RHD.