Photoinactivation of Mycobacteria in vitro and in a new murine model of localized Mycobacterium bovis BCG-induced granulomatous infection

Treatment of tuberculosis is currently hindered by prolonged antibiotic regimens and the emergence of significant drug resistance. Alternatives and adjuncts to standard antimycobacterial agents are needed. We propose that a direct attack utilizing photosensitizers and light-based treatments may be effective in curtailing Mycobacterium tuberculosis in discrete anatomical sites in the most infectious phase of pulmonary tuberculosis. To demonstrate experimental proof of principle, we have applied established photodynamic therapy (PDT) technology to in vitro cultures and an in vivo mouse model using Mycobacterium bovis BCG. We report here in vitro and in vivo PDT efficacy studies and the use of a three-dimensional collagen gel as a delivery vehicle for BCG, subcutaneously inserted, to induce specifically localized granuloma-like lesions in mice. When a benzoporphyrin derivative was utilized as the photosensitive agent, exposure to light killed extracellular and intracellular BCG in significant numbers. Collagen scaffolds containing BCG inserted in situ in BALB/c mice for 3 months mimicked granulomatous lesions and demonstrated a marked cellular infiltration upon histological examination, with evidence of caseating necrosis and fibrous capsule formation. When 10(5) BCG were present in the in vivo-induced granulomas, a significant reduction in viable mycobacterial cells was demonstrated in PDT-treated granulomas compared to those of controls. We conclude that PDT has potential in the treatment of localized mycobacterial infections, such as pulmonary granulomas and cavities.     

Vaccination with photodynamic therapy-treated macrophages induces highly suppressive T-regulatory cells

Background/purpose: The present study explores whether photodynamic therapy (PDT)‐induced apoptosis can increase the number of tolerogenic regulatory T cells (Treg) and limit collateral tissue damage. Methods: BALB/c mice were vaccinated subcutaneously three times with PDT‐induced apoptotic or thaw‐frozen, necrotic non‐infected autologous macrophages (MΦ). Two weeks after the last vaccination, mice were infected intradermally with 10⁶ promastigotes of Leishmania major. Results: Mice that received PDT‐induced apoptotic MΦ had fewer parasites and higher numbers of Treg than mice vaccinated with thaw‐frozen necrotic MΦ or phosphate‐buffered saline (PBS). Interleukin (IL)‐4 and IL‐6 were significantly suppressed, while IL‐10 was increased in mice that received the PDT‐induced apoptotic MΦ. The role of Treg in this process was confirmed through Treg transfer from vaccinated to naïve mice. Mice receiving CD4⁺CD25⁺ cells from mice vaccinated with PDT‐induced apoptotic MΦ showed smaller lesions 3 weeks after infection and lower parasitic burdens than mice that received Tregs from mice of thaw‐frozen necrotic MΦ or PBS groups. These changes were mediated by the depletion of CD3⁺CD8⁺ and NKT cells and increased levels of IL‐12p70 and interferon‐γ, IL‐10, and TGF‐β in the cutaneous leishmaniasis lesions. Conclusion: Vaccination with apoptotic MΦ‐induced tolerogenic Treg cells that limited collateral tissue damage and diminished parasitic burden.     

Non‐classical mechanism of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor channel block by fluoxetine

Antidepressants have many targets in the central nervous system. A growing body of data demonstrates the influence of antidepressants on glutamatergic neurotransmission. In the present work, we studied the inhibition of native Ca²⁺‐permeable and Ca²⁺‐impermeable α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptors in rat brain neurons by fluoxetine. The Ca²⁺‐impermeable AMPA receptors in CA1 hippocampal pyramidal neurons were weakly affected. The IC₅₀ value for the inhibition of Ca²⁺‐permeable AMPA receptors in giant striatal interneurons was 43 ± 7 μm . The inhibition of Ca²⁺‐permeable AMPA receptors was voltage dependent, suggesting deep binding in the pore. However, the use dependence of fluoxetine action differed markedly from that of classical AMPA receptor open‐channel blockers. Moreover, fluoxetine did not compete with other channel blockers. In contrast to fluoxetine, its membrane‐impermeant quaternary analog demonstrated all of the features of channel inhibition typical for open‐channel blockers. It is suggested that fluoxetine reaches the binding site through a hydrophobic access pathway. Such a mechanism of block is described for ligands of sodium and calcium channels, but was never found in AMPA receptors. Molecular modeling suggests binding of fluoxetine in the subunit interface; analogous binding was proposed for local anesthetics in closed sodium channels and for benzothiazepines in calcium channels.     

The neuromuscular system in continuously swimming cercariae from Belarus. II Echinostomata, Gymnocephala and Amphistomata

The neuromuscular system in cercariae of Moliniella anceps, Echinostoma revolutum, Cathaemasia hians, Psilochasmus oxyurus, Sphaeridiotrema globulus, Paramphistomum cervi and Diplodiscus subclavatus was studied with immunocytochemical methods and confocal scanning laser microscopy. The patterns of F-actin in the musculature, 5-HT immunoreactive (IR), FMRFamide-IR neuronal elements and ??-tubulin-IR sensory receptors were investigated. The general patterns of musculature, 5-HT- and FMRFamide-IR neuronal elements in the 12 species studied here and in paper I are similar to those observed in other cercariae and reflect the morphology of the groups. The musculature of the tail shows variations which are related to the different strategies of host finding. In the Echinostomatoidea and Paramphistomoidea, the striated musculature of the tail is well developed compared to that in the Xiphidiocercariae. Specialized muscle fibres were found in S. globulus, which are able to change the shape of the tail. Nine of the species studied have seven paired 5-HT-IR neurons in the body, and two species have eight. No correlation between the body size and the number of 5-HT-IR neurons was observed. However, the size of the neurons followed the body size. The number of 5-HT-IR neurons in the brain ganglia increased from the primitive to the advanced forms. The number of FMRFamide-IR transverse commissures in the body correlates with the size of the cercariae. Regardless of the differences in the second intermediate host, the distribution of ??-tubulin-IR sensory receptors shows a high degree of conformity in all species except in P. cervi, which encysts on plants.     

Selective Preparation of trans-Carveol over Ceria Supported Mesoporous Materials MCM-41 and SBA-15

Ce-modified mesoporous silica materials MCM-41 and SBA-15, namely 32 wt % Ce–Si–MCM-41, 16 wt % Ce–H–MCM-41 and 20 wt % Ce–Si–SBA-15, were prepared, characterized and studied in the selective preparation of trans-carveol by α-pinene oxide isomerization. The characterizations of these catalysts were performed using scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and FTIR pyridine adsorption. Selective preparation of trans-carveol was carried out in the liquid phase in a batch reactor. The activity and the selectivity of catalyst were observed to be influenced by their acidity, basicity and morphology of the mesoporous materials. The formation of trans-carveol is moreover strongly influenced by the basicity of the used solvent and in order to achieve high yields of this desired alcohol it is necessary to use polar basic solvent.     

Shortened erythrocyte sedimentation rate evaluation is applicable to hospitalised patients

BackgroundWestergren method, commonly used for erythrocyte sedimentation rate (ESR) determination, is simple and inexpensive. However, the 60 min required for the test are disadvantageous, especially for those departments/facilities where prompt evaluation is necessary. We investigated the possibility that earlier ESR recordings might correlate with standard 60-minute ESR and/or be predictive of the latter.MethodsDemographic and clinical data were collected from 220 randomly chosen adult patients hospitalised for various diseases in a medical department. ESR, determined by slightly modified Westergren method, was recorded at 15, 30 and 60 min. Correlation coefficients (r) between the standard and early ESR measurements were calculated for the entire group and for the separate subgroups divided according to patient age, sex and presence of anaemia or of inflammation.ResultsMean ± SD age of the patients was 61.3 ± 19.6, 55% were males; 45% had some inflammatory condition. Mean ± SD ESR values (mm) at 15, 30 and 60 min were 9.0 ± 12.1, 21.4 ± 21.8 and 35.9 ± 27.5, respectively. A statistically significant correlation was found between ESR measurements at 15 and 60 min (r = 0.833, p < 0.001). However, the strongest correlation was observed between 30 and 60 min measurements (r = 0.926, p < 0.001), irrespective of age, sex and presence of anaemia or of inflammation. Based on the ESR determination at 30 min (X), the predicted ESR value at 60 min (Y) could be calculated by a simple equation: Y = 10.7 + 1.2X.ConclusionSixty-minute ESR values can be predicted by the 30-minute estimation. Shortening the test by half an hour might bear practical importance.     

Ca2+ release-activated Ca2+ channel blockade as a potential tool in antipancreatitis therapy

Alcohol-related acute pancreatitis can be mediated by a combination of alcohol and fatty acids (fatty acid ethyl esters) and is initiated by a sustained elevation of the Ca²⁺ concentration inside pancreatic acinar cells ([Ca²⁺]_i), due to excessive release of Ca²⁺ stored inside the cells followed by Ca²⁺ entry from the interstitial fluid. The sustained [Ca²⁺]_i elevation activates intracellular digestive proenzymes resulting in necrosis and inflammation. We tested the hypothesis that pharmacological blockade of store-operated or Ca²⁺ release-activated Ca²⁺ channels (CRAC) would prevent sustained elevation of [Ca²⁺]_i and therefore protease activation and necrosis. In isolated mouse pancreatic acinar cells, CRAC channels were activated by blocking Ca²⁺ ATPase pumps in the endoplasmic reticulum with thapsigargin in the absence of external Ca²⁺. Ca²⁺ entry then occurred upon admission of Ca²⁺ to the extracellular solution. The CRAC channel blocker developed by GlaxoSmithKline, GSK-7975A, inhibited store-operated Ca²⁺ entry in a concentration-dependent manner within the range of 1 to 50 μM (IC₅₀ = 3.4 μM), but had little or no effect on the physiological Ca²⁺ spiking evoked by acetylcholine or cholecystokinin. Palmitoleic acid ethyl ester (100 μM), an important mediator of alcohol-related pancreatitis, evoked a sustained elevation of [Ca²⁺]_i, which was markedly reduced by CRAC blockade. Importantly, the palmitoleic acid ethyl ester-induced trypsin and protease activity as well as necrosis were almost abolished by blocking CRAC channels. There is currently no specific treatment of pancreatitis, but our data show that pharmacological CRAC blockade is highly effective against toxic [Ca²⁺]_i elevation, necrosis, and trypsin/protease activity and therefore has potential to effectively treat pancreatitis.     

Distal femoral varus osteotomy for lateral osteoarthritis of the knee: a minimum ten-year follow-up

Distal femoral varus osteotomy (DFVO) may be indicated for symptomatic lateral compartment gonarthrosis associated with valgus deformity in younger, active patients. Thirty-three consecutive DFVOs (31 patients) with a minimum follow-up of ten years (mean 15.1, range 10–25) were reviewed. Fifteen DFVOs were converted to total knee arthroplasty (TKA) and one DFVO was awaiting TKA, reaching an overall failure rate of 48.5% at a mean of 15.6 years (range 6–21.5). Of the remaining 17 DFVOs, ten (58.8%) had good or excellent results, two (11.8%) had fair results and five (29.4%) had poor results. Mean modified Knee Society scores improved significantly (p < 0.01) from 36.8 preoperatively to 77.5 at one year post DFVO. DFVO is a viable treatment alternative for lateral compartment gonarthrosis. Conversion to TKA is expected to be required in approximately half of the patients at a mean of 15.6 years.