Uptake of silica and carbon nanotubes by human macrophages/monocytes induces activation of fibroblasts in vitro -- potential implication for pathogenesis of inflammation and fibrotic diseases

The potential pathogenic effects of silica and carbon nanotubes (CNTs) on fibroblasts, macrophages/monocytes, and T cells were investigated. Human macrophage/monocytes were cultured and stimulated with silica, CNTs, or titanium particles. After adding human T cells to the stimulated macrophages/monocytes, the cells were added to cultured human fibroblasts. Upon microscopic examination, CNT stimulation after 24 hours showed centralization of macrophages/monocytes around the CNTs. Silica stimulation showed a significant increase of IL-1α and IL-1β in cultured medium, and an increased gene expression of CTGF in cultured fibroblasts at 1 hour, as well as an up-regulation of the COL1A2 gene at 24-hour time point. In addition to the same changes of IL-1α, IL-1β and the COL1A2 by silica, CNT stimulation showed an increase of IL-8 in cultured medium at 1-hour time point. Titanium stimulation yielded no significant changes. The results indicate a proinflammatory and/or profibrotic effect of silica and CNTs to cultured human cells including macrophages/monocyte, T cells and fibroblasts.

Delusional parasitosis over dermatological morbidity: diagnostic and therapeutic challenges

Delusional parasitosis is a rare psycho-dermatological disorder that lacks standard management guidelines. We report a case of an elderly woman with long standing multiple dermatological illnesses who later developed delusional parasitosis. We highlight the pertinent diagnostic and therapeutic challenges. We support multidisciplinary collaborative care combining effective pharmacotherapy with efficient non-pharmacological measures.

Methionine sulfoxide reductase A (MsrA) deficiency affects the survival of Mycobacterium smegmatis within macrophages

Methionine sulfoxide reductase A (MsrA) is an antioxidant repair enzyme which reduces oxidized methionine to methionine. Since oxidation of methionine in proteins impairs their function, an absence of MsrA leads to abnormalities in different organisms, including alterations in the adherence patterns and in vivo survival of certain pathogenic bacteria. To understand the role of MsrA in intracellular survival of bacteria, we disrupted the gene encoding MsrA in Mycobacterium smegmatis through homologous recombination. The msrA mutant strain of M. smegmatis exhibited significantly reduced intracellular survival in murine J774A.1 macrophages compared to the survival of its wild-type counterpart. Furthermore, immunofluorescence and immunoblotting of phagosomes containing M. smegmatis strains revealed that the phagosomes with the msrA mutant strain acquired both p67(phox) of phagocyte NADPH oxidase and inducible nitric oxide synthase much earlier than the phagosomes with the wild-type strain. In addition, the msrA mutant strain of M. smegmatis was observed to be more sensitive to hydroperoxides than the wild-type strain was in vitro. These results suggest that MsrA plays an important role in both extracellular and intracellular survival of M. smegmatis.

A role for complement C5 in organism containment and granulomatous response during murine tuberculosis

The molecular mechanisms underlying protective granuloma formation and control of bacterial growth during infection with Mycobacterium tuberculosis (MTB) are not yet completely understood. MTB-infected mice with natural deficiency in complement component C5 are unable to develop productive granulomatous responses, and are impaired in limiting organism growth within the lung. To address the molecular basis for this histologic dysfunction, congenic complement C5-sufficient (B10.D2-H2d H2-T18c Hcl/nSnJ) and complement C5-deficient strains (B10.D2-H2d H2-T18c Hco/oSnJ) congenic mice were infected with Mycobacterium tuberculosis, and cytokine and chemokine responses were examined. Twelve and 28 days after infection, lungs showed elevated messages for multiple inflammatory cytokines in both congenic strains. Interleukin (IL)-12(p40) mRNA was also induced during infection in C5-deficient mice, although levels were significantly decreased compared to C5-sufficient congenics. C5-deficient mice also demonstrated reduced KC, MIP-2, IP-10, and MCP-1 mRNA. The defect may directly involve C5-mediated effects on macrophage responses; C5-deficient bone marrow derived macrophages had significantly reduced secretion of KC, MIP-1 alpha and MIP-2 compared to C5-sufficient macrophages following in vitro infection. These findings indicate a role for C5 in mediation of chemotactic and activation events that are the basis for granulomatous responses during murine tuberculosis.

Significantly improved oral uptake of amikacin in FVB mice in the presence of CRL-1605 copolymer

Amikacin is an aminoglycoside which is used in the treatment of infection from gram negative bacteria. Amikacin is also used synergistically with penicillin against gram positive cocci. Amikacin cannot be delivered orally probably due to efflux of drug by P-glycoprotein pump in the brush border of intestine. We studied the possibility of delivering amikacin orally in mice using a copolymer (CRL-1605) as a vehicle. This copolymer inhibits P-glycoprotein pump. Two different doses of amikacin were used (500 mg/kg and 100 mg/kg). The concentration of polymer used was 132 mg/kg. The liquid formulation was fed to mice by gavage and serum amikacin concentrations were estimated after one hour and two hours using fluorescence polarization immunoassay. We observed a two fold increase in serum amikacin concentration when amikacin was orally delivered in the presence of CRL-1605 compared to controls (amikacin alone). We conclude that gastrointestinal absorption of amikacin is significantly increased in the presence of CRL-1605 in mice.

Induction of nitric oxide in human monocytes and monocyte cell lines by Mycobacterium tuberculosis

The induction of nitric oxide in human monocytes during mycobacterial infection has been a controversial issue. This study describes a comparative evaluation of the colorimetric and fluorometric methods for the detection of NO in response to Mycobacterium tuberculosis (MTB) infection in human peripheral blood-derived monocytes (PBM) and in U937, a human monocyte-derived cell line. MTB was grown in monocyte cultures in vitro for 7 or 10 days. RPMI 1640 medium, without antibiotics and supplemented with L-arginine, Hepes, 5% human AB serum, and tetrahydrobiopterin was used to support monocyte growth. As early as 72 h after infection, soluble nitrite was detectable in the medium using the fluorometric assay with diaminonaphthalene (DAN). Early induction of NO correlated with an increase in the levels of iNOS mRNA as quantitated by RT-PCR. NO levels increased progressively up to day 10 (PBM) or day 7 (U937), when 150-200 nM/10(6) cells of soluble nitrite accumulated in cultures, as measured by DAN. Furthermore, monocytes stained positively for human iNOS protein and peroxynitrite after infection with MTB. The induction of NO by MTB was inhibited by four different inhibitors of iNOS enzyme including N-monomethylarginine. Inhibition of NO resulted in the enhancement of the intracellular growth of two of five clinical isolates of MTB. NO released from a donor (S-nitroso-N-penicillamine) also had a direct bacteriostatic effect on the same isolates in broth cultures. MTB strains thus showed a differential susceptibility to intracellular and extracellular NO. In most of these assays, the Greiss reagent was limited by its sensitivity and remained negative for soluble nitrite throughout the 7-10 days of incubation. Thus, the colorimetric method, which is widely used, may give false-negative results in NO assays. This report also demonstrates for the first time that MTB induces mRNA for iNOS, iNOS protein, NO, and peroxynitrite in human monocyte/macrophage cultures.

Hypersusceptibility of A/J mice to tuberculosis is in part due to a deficiency of the fifth complement component (C5)

Mycobacterium tuberculosis (MTB) causes tuberculosis in man, which occurs as an acute, chronic or dormant disease reactivating over several years. The mechanisms of persistence and reactivation are not well understood and there is a need for animal models. Moderate-dose, aerosol infection killed A/J mice earlier than partially resistant C57Bl/6 mice, whereas a low-dose, aerosol-induced chronic infection exacerbated earlier in A/J mice. A/J mice lethally infected with MTB but drug cured of disease underwent reactivation of tuberculosis at least 100 days before similarly infected C57Bl/6 mice. Because A/J mice were C5 deficient, congenic B10 mice sufficient and deficient for C5 were infected intravenously with MTB to define the role of C5. C5-deficient mice again showed enhanced growth of MTB in the lungs. MTB-infected macrophages from C5-deficient mice showed enhanced growth of MTB coinciding with a reduced secretion of both cytokines (TNF-alpha, IL-1beta, IL-6, IL-12) and chemokines (KC, MIP-2 and MIP-1alpha) in A/J and TNF-alpha and chemokines in C5-deficient mice. Because C5-deficient macrophages could be activated from extraneous C5 and TNF-alpha we suggest that both play a role in the macrophage-mediated killing as well as containment mechanisms in tuberculosis.

Bioavailability of tobramycin after oral delivery in FVB mice using CRL-1605 copolymer, an inhibitor of P-glycoprotein

Tobramycin is an aminoglycoside used in the treatment of infection against gram-negative bacteria. Tobramycin cannot be delivered orally probably due to efflux of drug by a P-glycoprotein pump in the brush border of the small intestine. In this report we demonstrate oral delivery of tobramycin in FVB mice using CRL-1605 copolymer as a vehicle. This copolymer is known to inhibit P-glycoprotein. Two different doses of tobramycin (25 mg/kg and 200 mg/kg) were used. The concentration of CRL-1605 copolymer was 132 mg/kg. The liquid formulation was fed to mice by gavage and serum tobramycin concentrations were measured after one and two hours using the fluorescence polarization immunoassay. We observed significant increases in serum tobramycin concentrations when the drug was delivered orally with the copolymer compared to when the drug was delivered alone. We also performed a bioassay using Bacillus subtilis to confirm antibacterial effect of tobramycin in mice sera. This was to ensure that tobramycin did not undergo structural change during oral absorption when delivered in the copolymer vehicle. We observed minimal inhibition in growth of Bacillus subtilis in sera obtained from mice fed with tobramycin alone. In contrast, we observed almost complete inhibition of growth (most specimens) in sera obtained from mice fed with tobramycin in the presence of CRL-1605 copolymer. We conclude that tobramycin delivered orally in mice using copolymer 1605 is also bioactive.

Cytokine mRNA expression and serum cortisol evaluation during murine lung inflammation induced by Mycobacterium tuberculosis

A model system was characterized for investigating the potential role of cortisol in MTB induced immunopathology. Serum cortisol levels were evaluated in two mouse strains; C57BL/6 mice develop lung granulomas following acute Mycobacterium tuberculosis infection while A/J mice are deficient in this process. Serum cortisol levels were examined post infection, as well as immunoregulatory mRNA expression in the lung, measured using bioluminescent RT-PCR techniques. Prior to infection, the A/J mice constitutively maintain nearly 75&percent; higher serum cortisol than C57BL/6 mice. Both A/J and C57BL/6 mice exhibited approximately 30&percent; reduction in relative serum cortisol following infection. At no time did serum cortisol levels in the A/J fall below constitutive levels in the non-infected C57BL/6. The overall elevated cortisol in the A/J may affect pulmonary immunoresponsiveness; A/J mice exhibited earlier induction of IL-10 and TNF-alpha than C57BL/6 mice, with a relative lack of IL-2 during late infection. Conversely, the C57BL/6 mice demonstrated higher IL-12(p40) and IL-2 messages at the latter stages of disease than the A/J mice. Both mice demonstrated high IFN-&gama; mRNA. The high constitutive serum cortisol in the A/J mice may therefore contribute to establishment of an environment counter-productive to initiation of protective Th1 cell and granulomatous responses.

Effect of poloxamer CRL-1072 on drug uptake and nitric-oxide-mediated killing of Mycobacterium avium by macrophages

Mycobacterium avium-intracellulare complex (MAI) are common pathogens of opportunistic infections that are naturally resistant to most antibiotics and develop acquired resistance rapidly. An experimental drug, poloxamer CRL-1072, was found to have two unusual properties: it synergistically enhanced the activity of several antibiotics against MAI even though it had little activity as a single agent and it had greater activity against MAI in macrophage culture or in mice than in broth culture. Studies were undertaken to investigate the mechanisms of these effects. CRL-1072 was taken up by MAI and enhanced the uptake of fluorescent-labeled streptomycin and erythromycin in broth culture. The labeled antibiotics had reduced activity so the relevance for naive antibiotics must be inferred. In culture with human U937 monocytoid cells, CRL-1072 became localized in phagosomes and promoted uptake of streptomycin. Finally, CRL-1072 was found to induce production of mRNA for inducible nitric oxide synthase (iNOS) and nitric oxide (NO) by U937 cells. The antimycobacterial effect in macrophages was reversed by the iNOS inhibitor N-monomethyl L-arginine (NMMA), suggesting that CRL-1072 promotes killing of MAI by inducing NO. These effects were induced by noncytotoxic concentrations of CRL-1072. These data suggest that the antimycobacterial mechanisms of CRL-1072 include enhancing the delivery of antibiotic to targets within MAI and enhancement of the ability of macrophages to kill ingested organisms.

Identification of viable and non-viable Mycobacterium tuberculosis in mouse organs by directed RT-PCR for antigen 85B mRNA

Mycobacterium tuberculosis (MTB) the causative organism of tuberculosis can remain dormant as a non-culturable organism, reactivate and cause disease in man and animals. There is a need for proof of viability of such organisms in order to understand the process of reactivation. PCR for bacterial DNA cannot distinguish between viable and non-viable bacilli. We have tested a previously described two tube directed reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of mRNA of antigen 85B (Ag85B) of MTB that can distinguish between viable and non-viable organisms. Using a set of external and internal primers for Ag85B, a cDNA amplified product (216 bp) was seen among simulated samples containing only viable cfus at a sensitivity of >10 and <100 cfu/ml. Eucaryotic DNA rich normal mouse lung homogenate did not interfere among these samples. The method amplified the 216 bp product also among cfu positive tissues of naturally infected mice. Finally, in a mouse model of dormancy, direct RT-PCR detected a signal among multiple tissues that were negative for cfus and hence non-culturable. Ag85B is abundantly secreted by MTB and hyper-expressed under stress conditions. Thus the method to identify its mRNA message may be useful to detect viable but dormant bacteria.

Activity of poloxamer CRL-1072 against drug-sensitive and resistant strains of Mycobacterium tuberculosis in macrophages and in mice

The present experiments evaluated a new, highly refined poloxamer, CRL-1072, alone and in combination with antibiotics against drug-sensitive and -resistant organisms. In macrophage culture, CRL-1072 reduced the drug concentration inhibiting 99% of control growth of isoniazid (INH) from 10 to 0.15 mg/l (fractional inhibitory concentration=0.07) for a drug-resistant strain. CRL-1072 also increased the susceptibility of drug-resistant strains of Mycobacterium tuberculosis to INH, streptomycin, rifampicin, pyrazinamide, ethambutol, PAS, thiacetazone and ethionamide. Fractional inhibitory concentration values of <0.5 indicated significant synergistic activity. In studies of acute infection in mice, CRL-1072 was only weakly bacteriostatic when used as a single agent but increased the bactericidal activity of INH, streptomycin, rifampicin, pyrazinamide and clindamycin, but not that of ethambutol. CRL-1072 enhanced the bactericidal activity of streptomycin against a streptomycin resistant strain of M. tuberculosis in a murine infection.

Disruption of the genes encoding antigen 85A and antigen 85B of Mycobacterium tuberculosis H37Rv: effect on growth in culture and in macrophages

The mechanism of pathogenesis of Mycobacterium tuberculosis is thought to be multifactorial. Among the putative virulence factors is the antigen 85 (Ag85) complex. This family of exported fibronectin-binding proteins consists of members Ag85A, Ag85B, and Ag85C and is most prominently represented by 85A and 85B. These proteins have recently been shown to possess mycolyl transferase activity and likely play a role in cell wall synthesis. The purpose of this study was to generate strains of M. tuberculosis deficient in expression of the principal members of this complex in order to determine their role in the pathogenesis of M. tuberculosis. Constructs of fbpA and fbpB disrupted with the kanamycin resistance marker OmegaKm and containing varying amounts of flanking gene and plasmid vector sequences were then introduced as linear fragments into H37Rv by electroporation. Southern blot and PCR analyses revealed disruption of the homologous gene locus in one fbpA::OmegaKm transformant and one fbpB::OmegaKm transformant. The fbpA::OmegaKm mutant, LAa1, resulted from a double-crossover integration event, whereas the fbpB::OmegaKm variant, LAb1, was the product of a single-crossover type event that resulted in insertion of both OmegaKm and plasmid sequences. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis confirmed that expression of the disrupted gene was not detectable in the fbpA and fbpB mutants. Analysis of growth rates demonstrated that the fbpB mutant LAb1 grew at a rate similar to that of the wild-type parent in enriched and nutrient-poor laboratory media as well as in human (THP-1) and mouse (J774.1A) macrophage-like cell lines. The fbpA mutant LAa1 grew similarly to the parent H37Rv in enriched laboratory media but exhibited little or no growth in nutrient-poor media and macrophage-like cell lines. The targeted disruption of two genes encoding mycolyl transferase and fibronectin-binding activities in M. tuberculosis will permit the systematic determination of their roles in the physiology and pathogenesis of this organism.

Apoptosis in mycobacterium tuberculosis infection in mice exhibiting varied immunopathology

This study examined mechanisms contributing to pulmonary immunopathology following acute Mycobacterium tuberculosis (MTB) infection in vivo in a murine model. A/J and C57BL/6 mice were intravenously infected with MTB (Erdman). Pathological differences were found between strains, unrelated to pulmonary load of bacilli. A/J mice developed progressive interstitial pneumonitis, while C57BL/6 mice maintained granuloma formation. The contribution of FAS and FAS ligand-mediated apoptosis was assessed via bioluminescent reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemical staining, and TUNEL assessment of DNA fragmentation. Cytokine messages for pulmonary tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), as well as for the lytic molecules perforin and granzyme B, were quantified. Immunohistochemical staining for CD3 receptor was performed to monitor lymphocytic lung infiltration. Soon after infection, A/J mice exhibited increased pulmonary IFN-gamma message, concurrent with the appearance of CD3+ lymphocytes distributed throughout the lung. C57BL/6 mice exhibited perivascular cuffing, with no accompanying increase in IFN-gamma message. A/J mice also had elevated levels of FAS and FAS ligand message and protein early after infection, while the C57BL/6 mice had no increased expression of these molecules. Both strains exhibited qualitatively similar numbers of TUNEL-positive cells throughout infection, with a marked increase on day 7. Apoptotic cells appeared to co-localize with acid fast bacilli. It is therefore proposed that apoptosis during initial granuloma formation following MTB infection may occur through a FAS/FAS ligand-independent pathway. Moreover, a failure of completion of the FAS/FAS ligand-mediated apoptosis pathway in the A/J mice may contribute to inefficient elimination of lymphocytes, thus further aggravating pulmonary pathology.

Activities of poloxamer CRL-1072 against Mycobacterium avium in macrophage culture and in mice

Earlier studies reported that certain large hydrophobic poloxamer surfactants were able to inhibit the growth of Mycobacterium avium-M. intracellulare complex (MAI) in broth and to produce synergistic enhancement of the activity of rifampin. CRL-1072 was synthesized to have an optimal structure for antimicrobic effects and greater purity. Its MIC for MAI in broth was greater than 100 microg/ml. Surprisingly, its MIC for MAI growing in human U937 monocytoid cells was much lower, 5 microg/ml. A still lower concentration, 0.1 microg/ml, produced synergistic enhancement of the activities of clarithromycin, rifampin, amikacin, streptomycin, and clindamycin, but not isoniazid, against MAI infecting monocytoid cells. Mice tolerated injection of doses of CRL-1072 as high as 125 mg/kg of body weight. Pharmacokinetic analysis revealed that the copolymer had an elimination half-life of 60 h and suggested dosing regimens that might produce therapeutic concentrations in tissue. In a mouse model of acute MAI infection, CRL-1072 significantly enhanced the bactericidal activities of clarithromycin and rifampin when it was administered at 1.0 mg/kg intravenously (i.v.) three times per week. CRL-1072 given i.v. or orally also enhanced the bactericidal activity of clindamycin against MAI.

Relationship of survival, organism containment, and granuloma formation in acute murine tuberculosis

The relationship among organism growth, immunopathology, and survival was studied in C57BL/6 and A/J mice acutely infected with Mycobacterium tuberculosis (MTB) (Erdman). Although organisms grew at similar rates in the lungs of both mouse strains, A/J mice died prior to 14 days after infection, whereas C57BL/6 mice survived twice as long. The lungs of A/J mice exhibited necrotizing interstitial inflammation and widely distributed acid-fast bacilli without granuloma formation. In contrast, the lungs of C57BL/6 mice had relatively mild interstitial inflammation, which was replaced by focal granulomas, and acid-fast bacilli were primarily within granulomas. MTB induced similar granulomas for A/J and C57BL/6 mice in spleen and liver. In the lung, the A/J mice produced only transient messages for interferon-y (IFN-y), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-10, and inducible nitric oxide synthase (iNOS). The C57BL/6 mice, in contrast, produced a delayed but sustained response in the lung correlating with granuloma onset and characterized by high induction of IL-6, IFN-gamma, IL-1beta, IL-10, and TNF-alpha. Responses in the liver and spleen were also evaluated. These results demonstrate that histopathology and cytokine response to MTB infection varies among organs in mice. Increased survival during acute infection may, therefore, depend on the ability to contain organisms within granulomas in the lung.

Gas chromatographic/mass spectrometric identification and quantification of aniline after extraction from serum and derivatization with 4-carbethoxyhexafluorobutyryl chloride, a new derivative

Aniline, widely used as an intermediate in the synthesis of dye, is also used in the manufacture of pharmaceuticals, photographic developers, shoe polish, and other common substances. Exposure to aniline is toxic because it produces methemoglobin. Aniline levels are usually not measured in serum; in humans, blood methemoglobin levels are often measured as an index of exposure to aniline. In this article, we describe a method for the identification and the quantification of aniline by gas chromatography/mass spectrometry (GC/MS) after its extraction from human serum and derivatization with 4-carbethoxyhexafluorobutyryl chloride. Aniline, as well as the internal standard N-methyl aniline, was extracted from alkaline serum using chloroform. Aniline and the internal standard were derivatized with 50 microL of 4-carbethoxyhexafluorobutyryl chloride. After evaporating the excess derivatizing reagent, the residue was reconstituted in 50 microL of ethyl acetate and injected into the GC/MS. A positive identification of derivatized aniline can be made from the strong molecular ion at m/z 343. Similarly, derivatized internal standard showed a strong molecular ion at m/z 357. The within-run and between-run precisions of the assay were 3.8% and 5.8%, respectively, at an aniline concentration of 5 mg/L. The assay was linear for serum aniline concentrations of 0.5 mg/L to 25.0 mg/L. The detection limit was 0.1 mg/L. The assay was not affected by lipemia, hemolysis, or high bilirubin concentration in serum, and the assay was applicable to whole blood. We also fed mice (C57bl/6) with various concentrations of aniline and measured methemoglobin and blood concentrations of aniline. The methemoglobin percentage and aniline concentrations in blood increased with increasing aniline doses.

CRL-1072 enhances antimycobacterial activity of human macrophages through interleukin-8

CRL-1072 is a poloxamer surfactant that kills mycobacteria more effectively within macrophages than in broth cultures. Human macrophages treated with CRL-1072 synthesized interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in a dose-dependent manner. About 3000 pg of IL-8 per million human macrophages accumulated in cultures treated with 100-1500 ng of poloxamer, with mRNA message for IL-8 induced as early as 2 h. As macrophages do not have IL-RA receptors, a transwell culture was used to study the chemotactic and activating effects of IL-8 between CRL-1072-treated human macrophage effectors and polymorphonuclear neutrophil (PMN) targets. PMN were activated by IL-8 and secreted hydrogen peroxide and myeloperoxidase (MPO). MPO derived from PMN, in turn, activated monocytes for an enhanced killing of intracellular Mycobacterium avium. The ability of CRL-1072 to modulate macrophage-mediated activation of neutrophils and receive a feedback activation signal may form one mechanism by which its antimycobacterial activity is achieved in vivo.

Use of nonionic block copolymers in vaccines and therapeutics

Nonionic block copolymers synthesized from ethylene oxide and propylene oxide were developed specifically for use as surfactants. Because the sizes and relative positions of the hydrophobic polyoxypropylene (POP) and hydrophilic polyoxyethylene (POE) blocks can be altered during synthesis, copolymers with significantly different surfactant characteristics can be produced. Copolymers of this type are currently used as excipients in a wide variety of pharmaceutical products where they act as emulsifying, wetting, thickening, stabilizing, and dispersing agents. Copolymers with unique physicochemical properties have recently been developed through the use of new manufacturing and purification techniques, and these copolymers are being used as drug-active and drug-delivery components. In this review, we summarize the current status of these new copolymers in terms of research and product development. This includes the use of new, high molecular weight copolymers as vaccine adjuvants and as vaccine-delivery vehicles. The use of purified, pharmaceutical-grade copolymers as anti-infectives and as antibiotic-delivery systems for the treatment of established bacterial and viral infections is also reviewed. These novel uses for copolymers are significantly different from the excipient uses common to this type of product and demonstrate the widespread utility of synthetic surfactant polymers.

Immunohistochemical study of the expression of human groEL-stress protein in human nervous tissue

Monoclonal antibody (ML-30) directed against 65 kDa stress protein of mycobacteria, is shown to identify human cellular protein homologous with the groEL heat shock protein in many prokaryotes. Immunohistochemical survey of nervous tissue, both central and peripheral, from patients dying of various inflammatory, degenerative and neoplastic conditions and from experimental animals, using this antibody showed punctate granular staining of the cells to a variable degree. The astrocytes showed strong immunolabelling. The normal neurons and oligodendroglia stained variably, while abnormal neurons were darkly labelled. Ependymal cells showed apical granular positivity. The ubiquitinated inclusion bodies in amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease were not recognised by the ML-30 antibody. In diseased and stressed nervous tissue from experimental animals, the expression of the ML-30 recognisable stress protein was variable. The epitope recognised by ML-30 was found stable in postmortem tissues collected up to 36 h after death and processed for paraffin sectioning, after fixation in formalin for many years. Enhanced expression of the human groEL stress protein homologue in mammalian nervous tissue following various forms of stress may play a role in modulating the extent of tissue damage by autoimmune mechanism because of its high immunogenic nature and constitutive presence in the cells.

Activities of poloxamer CRL8131 against Mycobacterium tuberculosis in vitro and in vivo

A poloxamer surfactant, CRL8131, was evaluated for activity against Mycobacterium tuberculosis (Erdman) by itself and in combination with antibiotics in broth culture, in a macrophage cell line assay, and in testing with mice. In the broth culture, CRL8131 suppressed the growth of M. tuberculosis and produced synergistic effects in combination with isoniazid, rifampin, and streptomycin. It also displayed synergy with isoniazid and rifampin against two drug-resistant isolates. In the macrophage cell line assay, CRL8131 produced a synergistic effect on intracellular killing of M. tuberculosis by isoniazid, rifampin, streptomycin, pyrazinamide, thiacetazone, D-cycloserine, ethionamide, amikacin, clindamycin, and p-aminosalicylic acid. It demonstrated no synergy or antagonism with ethambutol, gentamicin, kanamycin, ciprofloxacin, or nalidixic acid. Finally, with C57BL/6 mice infected with M. tuberculosis, a combination of CRL8131 and either thiacetazone or pyrazinamide produced 100% survival at 40 days whereas the antibiotics produced only 33% survival and CRL8131 produced 0% survival when used as single agents. This improved survival rate was associated with a significant reduction in the number of organisms in the lungs and spleens of infected mice.

Chemotherapeutic activity of clofazimine and its analogues against Mycobacterium tuberculosis. In vitro, intracellular, and in vivo studies

Clofazimine (CFM), a riminophenazine drug, is primarily used in therapy for leprosy and Mycobacterium avium infections. With an objective of identifying drugs active against Mycobacterium tuberculosis, including those with multi-drug resistance, we investigated CFM and nine of its chemical analogues. Among these, B746 and B4101 had better activity than CFM against six drug-susceptible and nine single/multiple drug-resistant M. tuberculosis strains. B746 also showed slightly better activity than CFM against intracellular M. tuberculosis in J774A.1 macrophages and was comparable to CFM in its in vivo activity against experimental tuberculosis in C57BL/6 mice. Interestingly, it caused less pigmentation in internal organs.

Enhancement of drug susceptibility of multi-drug resistant strains of Mycobacterium tuberculosis by ethambutol and dimethyl sulphoxide

Strategies to augment conventional methods of drug delivery in treatment of multiple drug resistant tuberculosis are needed to achieve optimum results with available drugs. We have studied the effect of sub-minimum inhibitory concentrations (sub-MIC) of ethambutol and dimethyl sulphoxide on drug susceptibility of Mycobacterium tuberculosis strains both in vitro and in macrophages. At sub-MIC ethambutol between caused four and 64 fold increase in susceptibility to isoniazid rifampicin and streptomycin in four M. tuberculosis strains, resistant to these drugs. Incubation of the organisms with isoniazid and sub-MIC of dimethyl sulphoxide (2.5%) resulted in an eight-fold increase in susceptibility to the drug. Previous exposure of the organisms to sub-MIC of dimethyl sulphoxide also caused similar enhancement of susceptibility. Both ethambutol and dimethyl sulphoxide at the sub-MIC of sulphoxide also caused similar enhancement of susceptibility. Both ethambutol and dimethyl sulphoxide at the sub-MIC enhanced the activity of the anti-tuberculosis drugs against multiple drug resistant M. tuberculosis strains growing inside macrophages. Our data indicate that the agents which modify cell wall permeability can enhance the susceptibility of multiple drug resistant strains to drugs to which they were originally resistant. This could provide a new approach to treating drug resistant tuberculosis.

Enhancement of antibiotic susceptibility and suppression of Mycobacterium avium complex growth by poloxamer 331

The resistance of Mycobacterium avium complex (MAC) to antibiotics is thought to be enhanced by its outer glycolipid layer, which protects the organisms from antibiotics and host defense mechanisms. We hypothesized that surfactants which disrupt the lipid barrier might be of therapeutic value. We evaluated the ability of 10 poloxamer surfactants to inhibit the growth of MAC organisms and to potentiate antimycobacterial drug activity in broth culture using a radiometric assay. Very large, small, or hydrophilic poloxamers had little or no effect. However, certain hydrophobic poloxamers, especially P331, retarded the growth of most isolates of MAC and produced a synergistic effect with rifampin. The MIC of rifampin required to inhibit the growth of MAC was reduced from a mean of 14.6 micrograms/ml (range, 4 to > 32 micrograms/ml) to 1.4 micrograms/ml (range, < 1.125 to 4 micrograms/ml) by 1.0 mg of P331 per ml (P < 0.01). Enhancement of antibiotic susceptibility was observed with concentrations of poloxamer as low as 10 micrograms/ml. These studies suggest that P331 might be useful in increasing the effectiveness of antibiotic therapy of MAC infections.

Eccrine acrospiroma of eye lid--a case report

Tumours arising in the sweat glands of the eyelids are rare. A case of Eccrine Acrospiroma, otherwise, called clear cell hidradenoma, a benign sweat gland tumour of the lid in a female aged 70 years is being reported because of its rarity.

Antigenic analysis of Cysticercus cellulosae by crossed immunoelectrophoresis & its role in immune diagnosis of neurocysticercosis

The antigenic composition of Cysticercus cellulosae cysts excised from infected pig and autopsied human brain was analysed by crossed immunoelectrophoresis with an intermediate gel technique using rabbit hyperimmune serum. Normal pork muscle and human brain antigen were used to differentiate parasite derived components from that of host. Attempts were made to look for the rich source of parasitic immunodominant antigens by analysing preparations of different parts of cyst namely scolex and fluid using rabbit hyperimmune serum. Twenty three antigenic components were identified in sonicate extract of porcine cyst, of which 15 were parasite derived. On comparison with antigens of whole cyst sonicate, scolex showed 10, cyst fluid 9 and human cyst sonicate 11 parasite derived antigens. Serum and cerebrospinal fluid (CSF) of neurocysticercotic patients reacted with 12 parasite derived antigens of porcine cyst sonicate (PCS) in a heterogenous manner. It was also noticed that human cyst sonicate (HCS) lacked 4 of the parasite derived antigens present in the PCS.

Enhancement of the antigen-binding capacity of incomplete IgG antibodies to Brucella melitensis through Fc region interactions with staphylococcal protein A

Incomplete IgG anti-Brucella antibodies in human sera were detected using both a conventional ELISA and a modified method. In the ELISA procedure serum IgG was allowed to bind solid-phase B. melitensis antigen and, after washing, biotinylated staphylococcal protein A (BioSPA) was used as an Fc-specific tracer followed by streptavidin-HRP conjugate. In the modified method, serum IgG was co-incubated with a defined quantity of BioSPA in the presence of solid-phase antigen. BioSPA bound Fc regions of serum IgG irrespective of antigen specificity whilst antibodies which were specific for Brucella bound the solid-phase antigen through their Fab regions and were detected subsequently by streptavidin-HRP. IgG anti-Brucella antibodies were detectable with a 5-25-fold increase in sensitivity when they were thus 'activated' in situ with BioSPA. In contrast with the IgG antibodies of untreated human sera, BioSPA-activated IgG showed strong antigen binding capacity and resisted the dissociation effect of the chaotropic agent, guanidine hydrochloride. In similar experiments, BioSPA did not enhance the affinity of IgG anti-Salmonella antibodies of human sera towards S. typhi antigen. The activating effect of BioSPA on the incomplete IgG anti-Brucella antibodies from patients with brucellosis possibly involves a re-orientation of Fab sites.

The specificity of antibody response in experimental and natural bovine paratuberculosis studied by crossed immunoelectrophoresis with intermediate gel

The sonicate antigen (MPS) of a local strain (IVRI) of Mycobacterium paratuberculosis and a commercial lysate of Strain 18 were analysed using hyperimmune rabbit and calf antisera to MPS in crossed immunoelectrophoresis with intermediate gel (CIE-ig) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The rabbit antiserum was more potent than the calf antiserum and it precipitated 35 and 15 antigens, respectively, among MPS and lysate antigens. SDS-PAGE resolved 50 and 32 peptides among these antigens respectively, of which, 35 and 15 were precipitated by rabbit antiserum. A CIE-ig reference system, with 30 MPS antigens, was standardized and used to analyse antibody specificities among sera derived from animals experimentally and naturally infected with bovine paratuberculosis. Fourteen antigens of MPS were found to be reactive with these sera and among these, Antigens 2 and 5 were found to be serodominant; sonicate antigens of M. bovis BCG and M. avium did not contain these antigens. Both were high molecular weight (greater than 60 kDa) antigens which may be of serodiagnostic value.

Serology of tuberculosis. III. Crossed immunoelectrophoretic analysis of sera from tuberculosis and leprosy patients with antigens from BCG

Sera from tuberculous and leprous patients have been examined for antibody reactivities against components of BCG sonicate (BCGS) antigen. A crossed immunoelectrophoresis with intermediate gel reference system was used in which more than 40 components of BCGS could be identified. Forty (74.1%) out of 54 tuberculous sera and 68 (90.7%) out of 75 leprous sera reacted with at least 1 component of BCGS. While tuberculous sera reacted with 9 distinct components of BCGS, leprous sera reacted with at least 12. Components of BCGS precipitated by tuberculous sera were not specific as they were also precipitated by leprous sera. Overall, non-specific antibody responses were found to be dominant among tuberculous sera and by comparison, the reactivity of leprous sera with BCGS components was of a higher magnitude. Among tuberculous sera, precipitating activity was maximal among those taken from chronic treated cases with relapse followed by those obtained from treated and untreated new cases. Some components of BCGS to which both tuberculous and leprous sera showed strong reactivity have been characterized. It is concluded that immunoprecipitation methods with BCG derived antigens are not useful for the detection of a specific antibody response in tuberculosis or for discrimination between tuberculosis and leprosy.

Serology of tuberculosis. II. Measurement of antibodies to Mycobacterium tuberculosis by a passive haemagglutination test in human tuberculosis

A simple and sensitive passive haemagglutination (PHA) test has been evaluated in the serology of human tuberculosis. Double aldehyde stabilized red cells were sensitized with cell extracts and PPD antigens from M. tuberculosis (H37Rv) and used as reagents in the test. The study was conducted on sera from 71 bacteriologically confirmed cases of tuberculosis and their controls, inclusive of 59 healthy blood donors and 28 non-tuberculous chest disease patients. In addition, 318 random samples of sera and 107 finger prick blood samples collected on filter papers from apparently healthy people were examined. For comparative evaluation, tuberculous patients' sera were examined by enzyme linked immunosorbent assay (ELISA) and crossed immunoelectrophoresis (CIE). The distribution of IgG and IgM type antimycobacterial antibodies (AMA) in tuberculous patients' sera was evaluated by a modified PHA test. The results of the study indicated that the PHA test was a sensitive method for the quantitation of antibodies, which could be demonstrated in all groups of sera studied. The PHA test and ELISA with the antigens used were not found to be specific enough for the serodiagnosis of tuberculosis; the results indicated the need to investigate several immunological approaches for this purpose. Both tests did differentiate between the mean AMA levels of tuberculous patients and their controls and both showed treated and relapsed cases of tuberculosis to contain higher serum levels of antibodies than did new cases. Both tests were found to be more sensitive than CIE with the intermediate gel technique. The PHA test was found to be sensitive enough for the measurement of antibodies in finger-prick blood samples, indicating its potential for field studies.

Serology of tuberculosis. I. Standardization of passive haemagglutination test for the measurement of antibodies to Mycobacterium tuberculosis

A passive haemagglutination (PHA) test has been described for the measurement of antibodies to M. tuberculosis (H37Rv). Red cells stabilized successively with pyruvic aldehyde and glutaraldehyde were sensitized with soluble antigens from M. tuberculosis and used as reagents in the PHA test. In mice and rabbits immunized with M. tuberculosis antigens, the PHA test could reliably measure antibody response, following both primary and secondary immune stimuli. The sensitized red cells used for the PHA test were found to retain their haemagglutinating potency for 8 weeks and 4 months when stored appropriately at +4 degrees C and -20 degrees C, respectively. The test was found to be satisfactory in terms of sensitivity, simplicity and reproducibility.

Serology of leprosy. II. Demonstration of specific antibodies to mycobacterium leprae by counter current electrophoresis

A rapid and simple method for the demonstration of specific antibodies to Mycobacterium leprae using counter current electrophoresis (CCE) has been described. Three types of antigens (sonicate antigen, surface antigen and purified protoplasmic protein antigen) were prepared from purified M. leprae and tested against sera from patients with different types of leprosy, and their healthy household contacts, by CCE. Antibodies specific to M. leprae were demonstrated by CCE after absorption of sera with M tuberculosis and M. vaccae. All advanced forms of leprosy (LL and BL) and a lesser number of other forms of leprosy (BB, BT and TT) showed specific antibodies reactive with the three types of soluble antigens from M. leprae and antibodies reactive with soluble antigens from M. tuberculosis and M. vaccae. The latter type of antibodies were however removed by prior absorption of sera with respective mycobacteria. The applicability of the simple electrophoresis method in the serology of leprosy is discussed.

Serology of leprosy. I. Indirect hemagglutination test with stabilized sensitized red cells

An indirect hemagglutination (IHA) test has been described for the qualitative and quantitative detection of antibodies specific to Mycobacterium leprae. Aldehyde stabilized red cells were sensitized with a sonicate antigen prepared from M. leprae purified from armadillo liver. These cells were titrated against sera from patients with different types of leprosy, their healthy household contacts and patients with tuberculosis. Specific antibodies were demonstrated in leprous sera by IHA test after absorption of sera with M. tuberculosis and M. vaccae. All advanced forms of leprosy (LL and BL) and a variable number of other forms of leprosy (BB, BT and TT) showed a positive result with an IHA titre of 1 in 32 or above. None of the household contact sera nor sera from tuberculosis patients showed a positive IHA test. The application of the simple hemagglutination test in the immunoepidemiology of leprosy is discussed.