Cerebrospinal fluid inflammatory cytokine profiles of patients with neurotropic parasitic infections

The pathogenesis of chronic parasitic central nervous system (CNS) infections, including granulomatous amoebic meningoencephalitis (GAE), cerebral toxoplasmosis (CT), and neurocysticercosis (NCC), is primarily due to an inflammatory host reaction to the parasite. Inflammatory cytokines produced by invading T cells, monocytes, and CNS resident cells lead to neuroinflammation which underlie the immunopathology of these infections. Immune molecules, especially cytokines, can therefore emerge as potential biomarker(s) of CNS parasitic infections. In this study, cerebral spinal fluid (CSF) samples from suspected patients with parasitic infections were screened for pathogenic free-living amoebae by culture (n=2506) and PCR (n=275). Six proinflammatory cytokines in smear and culture-negative CSF samples from patients with GAE (n = 2), NCC (n = 7), and CT (n = 23) as well as control (n = 7) patients were measured using the Multiplex Suspension assay. None of the CSF samples tested was positive for neurotropic free-living amoebae by culture and only two samples showed Acanthamoeba 18S rRNA by PCR. Of the six cytokines measured, only IL-6 and IL-8 were significantly increased in all three infection groups compared to the control group. In addition, TNFa levels were higher in the GAE and NCC groups and IL-17 in the GAE group compared to controls. The levels of IL-1b and IFNg were very low in all the infection groups and the control group. There was a correlation between CSF cellularity and increased levels of IL-6, IL-8, and TNFa in 11 patients. Thus, quantifying inflammatory cytokine levels in CSF might help with understanding the level of neuroinflammation in patients with neurotropic parasitic diseases. Further studies with clinico-microbiological correlation in the form of reduction of cytokine levels with treatment and the correlation with neurological deficits are needed.

Identification of microbial agents in culture-negative brain abscess samples by 16S/18S rRNA gene PCR and sequencing

Despite clinical suspicion of an infection, brain abscess samples are often culture-negative in routine microbiological testing. Direct PCR of such samples enables the identification of microbes that may be fastidious, non-viable, or unculturable. Brain abscess samples (n = 217) from neurosurgical patients were subjected to broad range 16S rRNA gene PCR and sequencing for bacteria. All these samples and seven formalin-fixed paraffin-embedded tissue (FFPE) samples were subjected to species-specific 18S rRNA PCR for neurotropic free-living amoeba that harbour pathogenic bacteria. The concordance between smear and/or culture and PCR was 69%. One-third of the samples were smear- and culture-negative for bacterial agents. However, 88% of these culture-negative samples showed the presence of bacterial 16S rRNA by PCR. Sanger sequencing of 27 selected samples showed anaerobic/fastidious gram negative bacteria (GNB, 38%), facultative Streptococci (35%), and aerobic GNB (27%). Targeted metagenomics sequencing of three samples showed multiple bacterial species, including anaerobic and non-culturable bacteria. One FFPE tissue revealed the presence of Acanthamoeba 18S rRNA. None of the frozen brain abscess samples tested was positive for 18S rRNA of Acanthamoeba or Balamuthia mandrillaris. The microbial 16/18S rRNA PCR and sequencing outperformed culture in detecting anaerobes, facultative Streptococci and FLA in brain abscess samples. Genetic analyses of 16S/18S sequences, either through Sanger or metagenomic sequencing, will be an essential diagnostic technology to be included for diagnosing culture-negative brain abscess samples. Characterizing the microbiome of culture-negative brain abscess samples by molecular methods could enable detection and/or treatment of the source of infection.

Primary systemic amyloidosis of tongue with chondroid metaplasia

Amyloid is a pathologic proteinaceous substance deposited between cells in various tissues in a variety of clinical conditions. We report a case of amyloidosis of tongue with extensive chondroid metaplasia diagnosed on incisional biopsy in a multiple myeloma patient, who underwent autologous peripheral blood stem cell transplant for the same in 2010 and now presented with disease relapse after 2 years.

Preparation and Characterization of Metformin Hydrochloride - Compritol 888 ATO Solid Dispersion

Metformin hydrochloride (MET) sustained-release solid dispersions (SD) were prepared by the solvent evaporation and closed melt method, using compritol 888 ATO as the polymer with five different drug-carrier ratios. Characterization of solid dispersion was carried out by Fourier Transform Infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD). The FTIR and UV studies suggested that no bond formation had occurred between the polymer and the drug. DSC and XPRD results ruled out any interaction or complex formation between the drug and the polymer. The formulated SD had acceptable physicochemical characters and SD with a 1 : 4 drug : Polymer ratio, which released the drug over an extended period of eight-to-ten hours. The data obtained from the in vitro release studies were fitted with various kinetic models and were found to follow the Korsmeyer-Peppas equation. The prepared SD showed good stability over the studied time period. The solvent evaporation method was found to be more helpful than the closed melt method, giving the sustained release action. The SD with a 1 : 4 ratio of drug to polymer, by the solvent evaporation method, was selected as the most effective candidate for the subsequent development of a well-timed, sustained-release dosage form of the drug.

Myasthenia gravis and acetylcholine receptor antibodies: a clinico immunological correlative study on South Indian patients

Acquired myasthenia Gravis (MG), a disorder of impaired neuromuscular transmission is recognized as an autoimmune disorder, with a majority of the patients having antibodies against acetylcholine receptor (AChR antibodies) in the serum.

Formulation and evaluation of extended-release solid dispersion of metformin hydrochloride

The purpose of this research was to formulate and characterize solid dispersion (SD) of metformin hydrochloride using methocel K100M as the carrier by the solvent evaporation and cogrinding method. The influence of drug polymer ratio on drug release was studied by dissolution tests. Characterization was performed by fourier transform spectroscopy (FTIR), ultraviolet, differential scanning calorimetry and X-ray powder diffractometry. The optimized formulation was subjected to accelerated stability testing as per ICH guidelines. Release data were examined kinetically. SD with 1:4 and 1:5 ratio of drug to polymer obtained by solvent evaporation and cogrinding were selected as the best candidates suitable for prolonged-release oral dosage form of metformin.

Do cytokines have any role in Wilson's disease?

The aim of this study was to determine the serum cytokine levels in patients with Wilson's disease (WD) and correlate with phenotype, therapeutic status and laboratory data. In this cross-sectional study, the serum levels of cytokines were estimated in 34 patients (M : F, 23 : 11; drug-naive, 11) with WD (mean age: 13.8 +/- 8.6 and 19.6 +/- 9.03 years) and compared with 30 controls. The following serum cytokines were analysed using enzyme-linked immunosorbent assay: (i) tumour necrosis factor (TNF)-alpha, (ii) interferon (IFN)-gamma, (iii) interleukin (IL)-2, (iv) IL-6 and (v) IL-4. Serum TNF-alpha (P < 0.001), IFN-gamma (P = 0.005) and IL-6 (P < 0.001) were detectable in WD compared with controls. However, serum level elevation of IL-4 (P = 0.49) and IL-2 (P = 0.11), although detectable compared with controls, was statistically insignificant. The disease severity and therapeutic status did not affect the cytokines. Presence of anaemia, leucopenia, thrombocytopenia, pancytopenia and hepatic dysfunction did not influence cytokine levels. There was a significant negative correlation between IL-6 and ceruloplasmin (P = 0.04) and anti-inflammatory cytokines (IL-4) and copper level (P = 0.01). Serum cytokines, both proinflammatory and anti-inflammatory subtypes, were elevated significantly in patients with WD. Further studies would establish their role in its pathogenesis.

Impact assessment of coal mines in Erai watershed of Chandrapur district using geoinformatics

The industrial development and growing population in India is in demand of more energy. Coal based thermal power generation is a major source of energy and is expanding at a very high rate leading to over exploitation of coal reserves, which is causing adverse impacts on the environment. Remote sensing and GIS techniques have been found to be useful in mapping and monitoring of dynamic changes taking place due to mining activity. Satellite based environmental impact assessment involves various aspects, such as land use, water resources, land degradation, etc. These studies help in formulating environmental management plan for the mining sector. Coal mines in Erai watershed of Chandrapur district so far have lost 2139.68 hectares of land constituting a fertile agriculture land, reserve forest, protected forest and natural river course of Erai river, Upsa nala and Motaghat nala severely affecting the watershed eco-system. Therefore, an in-depth impact assessment study of coal mines in Erai watershed of Chandrapur district was carried out using geoinformatics and the results are presented in this paper.

Metabolomics

Metabolomics is based on the simultaneous analysis of multiple low-molecular-weight metabolites from a given sample. The goals of metabolomics are to catalog and quantify the myriad small molecules found in biological fluids under different conditions. The metabolomics represents the collection of all metabolites in a biological organism, and metabolic profiling can give an instantaneous 'snapshot' of the physiology of that cell. Together with the other more established omics technologies, metabolomics will strengthen its claim to contribute to the detailed understanding of the in vivo function of gene products, biochemical analysis, regulatory networks and more ambitious, the mathematical description and simulation of the whole cell in the systems biology approach. This phenomenon will allow the construction of designer organisms for process application using biotransformation and fermentative approaches making effective use of single enzymes, whole microbial and even higher cells and allows the connection of data from genomics, proteomics to enables coordinating the timing of the analysis to physiologically important windows.

Aminoglycoside-resistance mechanisms in multidrug-resistant Staphylococcus aureus clinical isolates

Aminoglycoside resistance in six clinically isolated Staphylococcus aureus was evaluated. Genotypical examination revealed that three isolates (HLGR-10, HLGR-12, and MSSA-21) have aminoglycoside-modifying enzyme (AME) coding genes and another three (GRSA-2, GRSA-4, and GRSA-6) lacked these genes in their genome. Whereas isolates HLGR-10 and HLGR-14 possessed bifunctional AME coding gene aac(6')-aph(2''), and aph(3')-III and showed high-level resistance to gentamycin and streptomycin, MSSA-21 possessed aph(3')-III and exhibited low resistance to gentamycin, streptomycin, and kanamycin. The remaining three isolates (GRSA-2, GRSA-4, and GRSA-6) exhibited low resistance to all the aminoglycosides because they lack aminoglycoside-modifying enzyme coding genes in their genome. The transmission electron microscopy of the three isolates revealed changes in cell size, shape, and septa formation, supporting the view that the phenomenon of adaptive resistance is operative in these isolates.

High-level oxacillin and gentamycin resistance with reduced susceptibility to vancomycin in Staphylococcus aureus-carrying mecA and femA gene complex

Staphylococcus aureus oxiva 10 and oxiva 14 strains clinically isolated from diabetic patients were resistant to gentamycin and oxacillin The minimal inhibitory concentrations (MICs) of oxacillin and gentamycin were 720 and >2048 microg/mL, respectively, for oxiva 10 and 680 and 400 microg/mL. respectively, for oxiva 14; both strains carry mecA and femA genetic determinants in their genomes. In addition, both are vancomycin-intermediate Staphylococcus aureus (VISA) isolates. The addition of vancomycin led to significant decreases in oxacillin resistance of both oxiva 10 and oxiva 14 strains, whereas the addition of vancomycin to gentamycin plates showed a decrease in gentamycin resistance of non-high-level gentamycin-resistant (non-HLGR) oxiva 14 and indifference in gentamycin resistance in HLGR oxiva 10. Transmission electron microscopy of representative strains unveils a remarkable increase in the thickness of the cell wall, indicating that thickening of the cell wall is a common phenotype associated with vancomycin resistance in VISA isolates. The present study reports that the rate of synergism and synergistic effect in the combination vancomycin-gentamycin vary according to the MICs of gentamycin.

Disseminated crytococcosis with extensive cutaneous involvement in AIDS

Cutaneous infections is observed in 15% of patients with disseminated cryptococcosis with AIDS. We present here a case of a 34 years old female with AIDS. She presented with multiple skin coloured umbilicated over face, neck, trunk and limbs, which mimicked molluscum contagiosum and kaposi sarcoma. The tissue from cutaneous lesions was collected by excision biopsy and processed by standard mycological methods. Cryptococcus neoformans was isolated and identified. Cerebrospinal fluid (CSF) also yielded the growth of C. neoformans . Cryptococcal antigen was detected with a titre of 1024 by Latex agglutination, is serum and CSF. Her serum was reactive for HIVI and 2 antibodies. The CD4 lymphocytes count was 80/cmm. The HIV viral load was 2,48,084 copies/mL. She was treated with amphotericin B injectable and oral fluconazole. She responded well and lesions regressed.

Enhanced antibody activity in serum depleted of antigen

Presence of antigen and antibodies in a sample may interfere with the antibody, as well as with antigen detection assays. In such a situation, avidity of the probing antigen or antibody plays the key role in the assay. In the present study, using monoclonal antibodies against a mycobacterial antigen, lipoarabinomannan, patient serum is depleted of mycobacterial antigen by capture immunoradiometric assay and this antigen-depleted serum is tested for anti-lipoarabinomannan antibodies by inhibition immunoradio-metric assay. It is observed that serum, after depletion of antigen, revealed enhanced antibody activity compared to initial levels. It, therefore, appears that the avidity of the probing monoclonal antibody may detach the antigen from the loosely attached complexes and renders the complexed antibody free, thus increasing the reactive antibody molecules in the serum.

Multi-level screening of a proposed hazardous waste treatment and disposal facility site--a case study

A comprehensive environmental assessment (EA) is a pre-requisite before the site for developing a hazardous waste treatment and disposal facility (HWTDF) is selected. However, the resource limitations, especially for developing countries, often dictate that the detailed EA be restricted to those sites, which are constraint free and have low hazard potentials. Thus, a preliminary screening exercise for assessing the suitability of site for developing the HWTDF needs to be carried out to avoid huge costs involved in detailed EA. While screening a HWTDF site, various factors such as present land use, ecologically sensitive areas, geology and hydrogeology of the area, the quality and quantity of wastes, engineered safeguards, and the operational procedures that need to be adopted. are required to be addressed. In this paper, a multi-level screening criteria employing Remote Sensing, Constraint Mapping, Groundwater Pollution Potential Index (DRASTIC Index), and the Site Ranking was used to assess the suitability of a proposed site for the development of HWTDF. The study helped to identify various constraints at the proposed site and their significance on the development of the HWTDF.

Detection of disease related immune complexes in the serum of leprosy patients. A novel single step method

Mycobacterium leprae antigen and antibody complexes could be detected in the serum of leprosy patients using monoclonal antibody ML34 and anti-BCG antibodies by enzyme-linked immunosorbent assay. This simplified system detects disease related complexes without the need for isolating and purifying them from the serum. Immune complexes captured using monoclonal antibody ML34 revealed positivity in seven out of eight neuritic, two out of nine tuberculoid (TT), five out of ten borderline tuberculoid (BT), four out of ten borderline lepromatous (BL) and four out of ten lepromatous (LL), leprosy cases. One of the controls also showed immune complex of an IgM type. Anti-BCG based IgG immune complexes assay revealed positivity in six out of eight neuritic, one out of nine TT, four out of ten BT, two out of ten BL, four out of ten LL leprosy cases, and two out of 24 healthy controls. IgM type of mycobacterial immune complexes were almost negligible. Capture of complexes using monoclonal antibody ML34 which is against lipoarabinomannan of M. leprae seems to work better than polyclonal anti-BCG antibody. The probable role of immune complexes in nerve damage needs to be evaluated, as very high levels of immune complexes are found in neuritic leprosy by both the assays. The above test would be useful in immunodiagnosis of neuritic leprosy and also in cases where antibody response is not detectable because of the formation of immune complexes.

Preceding infection as a risk factor of stroke in the young

INTRODUCTION

The cause of stroke in the young remains unknown in 20-50% of the patients. Infections preceding stroke have been recently recognised to be an independent risk factor of stroke.

MATERIAL AND METHODS

Sixty consecutive patients aged 40 years or less presenting with ischaemic completed stroke are taken up for the study. Patients with neurological deficit of less than 24 hours, evidence of haemorrhage on CT scan, infection occurring after the onset of stroke were excluded. Controls consisted of age and sex matched persons residing in the same area. Both the groups were enquired about preceding fever and infections and were examined for evidence of infections. Serum was examined for antibodies against measles, herpes simplex, and Japanese B encephalitis viruses. Cultures were put up from appropriate samples and CSF examined in patients only.

RESULTS

Evidence of infection was noted in 26 (43.3%) of patients and 6 controls (p < 0.001). History of fever was elicited in 23 patients and 3 controls while 15 patients were febrile on examination at admission. Signs of local infection was observed in 14 patients and one control. The commonest site of infection was respiratory tract. Cultures were positive in 11 patients, commonest being beta haemolytic streptococci in six from throat. Conventional risk factors were identical in both groups of patients with and without evidence of preceding infection. Smoking and alcoholism were significantly higher in patients with preceding infection.

CONCLUSION

Preceding infection is an important risk factor of stroke in the young. Smoking and alcoholism are more frequent in patients with preceding infection. Whether they predispose the individual for infection or infection increases the stroke risk in them needs to be examined.

Cytotoxic and anticancer activities of some 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides

A series of 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides demonstrated marked cytotoxicity towards approximately 55 human tumour cell lines from different neoplastic diseases. In general they were more potent than melphalan and displayed selective toxicity towards human leukemic cells. A representative compound, 1-phenyl-2-dimethyl-aminomethyl-2-propen-1-one hydrochloride (2a), had similar cytotoxicity as melphalan towards murine P388 and L1210 leukemic cells. In addition, 2a reduced the sizes of a number of human tumour xenografts including colon, prostatic and melanotic cancers passaged in athymic mice. Compound 2a showed excellent activity towards Ehrlich ascites carcinoma and B16F1 melanoma in mice which was enhanced using niosomes. One may conclude from the data generated that 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides are a novel series of cytotoxic and anticancer agents.

Identification of antibody responses to Mycobacterium tuberculosis antigens in the CSF of tuberculous meningitis patients by Western blotting

One of the adjunctive modes of diagnosing tuberculous meningitis (TBM) is to detect immune responses in the cerebrospinal fluid (CSF) to the Mycobacterium tuberculosis antigen. Up to 70% of clinical TBM reveal the presence of antimycobacterial antibody by the enzyme-linked immunosorbant assay. Defining the specificity of this immune response by Western blotting on separated M. tuberculosis antigen has been attempted in this study. Only antimycobacterial antibody-positive TBM cases were included in the study. An analysis of 30 such TBM cases showed a major immune reactivity to the 30- to 40-kDa region (93%) while a lower degree of immune reactivity was seen to the 14-kDa region (87%) and to the 18- to 25-kDa region (60%). Grossly the antibody reactivity on Western blot correlated with the ELISA results. Assessment of antimycobacterial antibody in the neurologic control CSF samples of pyogenic meningitis [n = 10], cryptococcal meningitis [6], neurocysticercosis [28], neurosyphilis [8], viral meningoencephalitis [8], carcinomatous meningitis [8], iatrogenic meningitis [6], and nonneurological control CSF samples from patients undergoing spinal anesthesia [20] revealed the presence of antibody in the CSF of 2 of the 10 pyogenic meningitis and 5 of the 28 neurocysticercosis cases. A Western blot analysis of these 7 cases revealed immune reactivity to 30- to 40-kDa regions only in 2 cases (1 of pyogenic and 1 of neurocysticercosis). The remaining 5 CSF samples did not reveal any immune reactivity on Western blotting, although ELISA demonstrated antimycobacterial antibodies. The antibody response to M. tuberculosis lipoarabinomannan and 38-kDa antigen by ELISA revealed 70.58 and 41.17% positivity, respectively. Thus this study has demonstrated that, by Western blotting, the major immune response is to the 30- to 40-kDa region, namely, lipoarabinomannan. Further, this finding will be useful for specific immunodiagnosis of the TBM.

Significance of mycobacterial immune complexes (IgG) in the diagnosis of tuberculous meningitis

SETTING

Tuberculous meningitis (TBM) has high mortality, especially in children. Early accurate diagnosis and adequate treatment would reduce this mortality. Diagnosis of TBM remains an enigma because of low cerebrospinal fluid (CSF) culture positivity for Mycobacterium tuberculosis and weak clinical correlation with conventional immunoassays.

OBJECTIVE

To evaluate significance of mycobacterial immune complexes (IgG) and anti-mycobacterial antibodies in the diagnosis of TBM.

METHOD

CSF from TBM patients and various types of other neurological (both infectious and non-infectious) and non-neurological cases was studied for the presence of IgG and anti-mycobacterial antibodies using antigen capture (by anti-BCG) and multilayered ELISA (using M. tuberculosis soluble extract), respectively.

RESULTS

IgG in CSF could be detected in 33 of 55 (60%) and anti-mycobacterial antibodies in 30 of 55 (55%) TBM cases. Presence of IgG, anti-mycobacterial antibodies or both could be detected in 45 of 55 (82%) of the TBM cases. Excepting three of the pyogenic meningitis CSF, none of the infectious (49), non-infectious neurological cases (30) and non-neurological controls (32) showed the presence of IgG or anti-mycobacterial antibodies.

CONCLUSION

Detection of IgG along with anti-mycobacterial antibodies aids in diagnosis of a large proportion of TBM cases.

Histological and immunological correlates of suspected leprosy lesions

Thirty-two subjects with suspected leprosy lesions were investigated to assess various modalities of sensibility and sweat function and these were correlated with immunological and histological parameters. It was found that pain and temperature, mediated by small unmyelinated fibres were impaired in the early lesions. Impairment of sweat function was seen only when one of the modalities of sensibility was also affected. Antibodies specific to a protein (35 kDa) antigen and phenolic glycolipid 1 of Mycobacterium leprae were positive in nine and 12 cases respectively, while 15 of the 31 biopsies revealed the presence of mycobacterial antigens in these lesions. The implications of these findings are discussed.

Detection of antibodies against phenolic glycolipid-1 (PGL-1), 35-kDa and 30-40-kDa components of Mycobacterium leprae in the cerebrospinal fluid of of leprosy patients

The involvement of the central nervous system (CNS) in lepromatous leprosy (LL) patients was investigated; 33 patients were examined clinically in detail and upper motor neuron involvement was observed in eight and lower motor neuron in three of these patients. Anti-Mycobacterium leprae antibodies could be detected in the CSF by PGL-1 enzyme-linked immunosorbent assay (ELISA) and monoclonal antibody (MAb) based competitive assays against defined epitopes on the 35-kDa protein and 30-40-kDa polysaccharide (lipoarabinomannan) antigens with MAbs MLO4 and ML34, respectively. Antibodies against PGL-1 and 35-kDa protein were observed in more subjects than antibodies against the 30-40-kDa antigen. Some correlation was observed between the upper motor neuron signs and antibody positivity for 35-kDa and PGL-1 antigens in the CSF of these patients.

Suppressive effect of circulating immune complexes from leprosy patients on the lymphocyte proliferation induced by M. leprae antigens in healthy responders

The effect of circulating immune complexes, isolated in the form of polyethylene glycol (PEG) precipitates from leprosy patients, on lymphocyte proliferation was studied. The results obtained showed that PEG precipitates obtained from the borderline lepromatous/lepromatous (BL/LL) types of leprosy patients and those undergoing erythema nodosum leprosum (ENL) had significant suppressive effects on the lymphocyte proliferation induced by Mycobacterium leprae antigens in healthy responders. The percent decreases in the mean values of delta cpm in the presence of PEG precipitates from the BL/LL and ENL groups were found to be 46.8 +/- 22.4 and 65.0 +/- 24.3, respectively. However, no significant suppressive effects (except for ENL PEG precipitates) of these PEG precipitates were observed on the lymphocyte proliferation induced by tuberculin (PPD). Further, PEG precipitates alone (in the absence of M. leprae antigen) from the BL/LL and ENL groups were found to have no effect on the lymphocyte proliferation.

Synthesis and biological evaluation of a fluorescent analogue of folic acid

A fluorescein derivative of the lysine analogue of folic acid, N alpha-pteroyl-N epilson-(4'-fluoresceinthiocarbamoyl)-L-lysine (PLF), was synthesized as a probe for dihydrofolate reductase (DHFR) and a membrane folate binding protein (m-FBP). Excitation of PLF at 282 nm and at 497 nm gave a fluorescence emission maximum at 518 nm. Binding of PLF to human DHFR or human placental m-FBP results in approximately a 20-fold enhancement in the magnitude of the fluorescence emission, suggesting that the ligand interacts with a hydrophobic region on these proteins. Additional evidence suggests that an energy transfer may occur between the pteridine and the fluorescein moieties. PLF binds to the active site of human DHFR since methotrexate (MTX) competes stoichiometrically and the denatured enzyme in the presence of PLF did not exhibit fluorescent enhancement. The dissociation constant for the fluorescein derivative with respect to human DHFR is 115 nM as compared to 111 nM for folic acid. The Ki value for the competitive inhibition of human DHFR by the fluorescent analogue of folic acid is 2.0 microM compared to 0.48 microM for folic acid. PLF was reduced to N alpha-(7,8-dihydropteroyl)-N epilson-(4'-fluoresceinthiocarbamoyl)-L-lysine (H2PLF) and assayed by the enzymatic conversion to the tetrahydro derivative. The Km value for human DHFR for the dihydrofolate analogue is 2.0 microM. The KD value for H2PLF to human DHFR is 47 nM as compared to 44 nM for dihydrofolate. The KD values for both H2PLF and PLF indicate that the fluorescein moiety does not significantly affect folate binding in enzyme binary complexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens of Mycobacterium leprae in the cerebrospinal fluid of leprosy patients: detection by monoclonal-antibody-based sandwich immunoradiometric assay and avidin/biotin immunoblotting

Mycobacterium leprae antigens could be detected in the cerebrospinal fluid (CSF) of patients with leprosy, using a monoclonal-antibody-based sandwich immunoradiometric assay (SIRMA). Antigens of 12 kD, 35 kD and 30-40 kD were detected using ML06, ML04, and ML34 monoclonal antibodies, respectively. The 30-40-kD polysaccharide antigen, although present in larger amounts in M. leprae than the 12-kD and 35-kD protein antigens, was found in the CSF of comparatively fewer subjects. The antigen capture assay has been found sensitive to the level of nanograms. Avidin-biotin-based immunoblotting using pooled leprosy sera detected a larger number of antigens than using anti-M. leprae antisera raised in rabbits. The immunoblotting of CSF samples revealed about three antigens in the region of 100-160 kD and three more in the region of 45-60 kD as probed by leprosy sera. This study has for the first time revealed the presence of M. leprae antigens in the CSF of leprosy patients and the probable involvement of the central nervous system in leprosy.

Detection of Mycobacterium leprae antigens in the sera of leprosy patients by sandwich immunoradiometric assay using monoclonal antibodies

An immunological technique for demonstration of Mycobacterium leprae antigen in sera was developed by using specific as well as cross-reactive monoclonal antibodies. The sandwich immunoradiometric assay which we developed is a simple, robust assay that is sensitive to the nanogram level. Sera from 72 leprosy patients were screened for the presence of antigen by this assay. A total of 69% of untreated tuberculoid leprosy patients showed 35-kDa antigen positivity, and 45% of these patients showed anti-35-kDa antibody positivity. Consistently higher antigen positivity rates for the 35-, 12-, and 30- to 40-kDa components of M. leprae were observed in lepromatous leprosy patients than in tuberculoid leprosy patients. During the course of therapy the antigen positivity rate gradually declined, and the antigen could not be detected in any of the 15 patients with subsided cases of leprosy. As antigen is presumably in excess before the antibody response is evoked, our experimental approach for antigen detection is likely to be useful by itself or along with antibody detection for diagnosis of early leprosy.

Inhibition of mammalian folylpolyglutamate synthetase and human dihydrofolate reductase by 5,8-dideaza analogues of folic acid and aminopterin bearing a terminal L-ornithine

Six new 5,8-dideaza analogues of folic acid and aminopterin containing a terminal L-ornithine residue were prepared by using multistep synthetic sequences. Each was evaluated as an inhibitor of hog liver folylpolyglutamate synthetase and human dihydrofolate reductase. Structural modifications at positions 2, 4, 5, and 10 were included to help define structure-activity relationships for compounds of this type. The compound N alpha-(4-amino-4-deoxy-5-chloro-5,8-dideazapteroyl)-L-ornithine (3f) was identified as the most potent inhibitor of mammalian folylpolyglutamate synthetase reported thus far (Ki congruent to 2 nM). Its 4-oxy counterpart, N alpha-(5-chloro-5,8-dideazapteroyl)-L-ornithine, was only 5-fold less inhibitory than 3f toward folylpolyglutamate synthetase but was found to be a much weaker inhibitor of dihydrofolate reductase than 3f.

Comparison of the biological effects of selected 5,8-dideazafolate analogues with their 2-desamino counterparts

Three new 5,8-dideaza analogues of folic acid devoid of an amino group at position 2 have been prepared by using synthetic routes patterned after earlier methodologies. They were 2-desamino-5,8-dideazaisofolic acid, 2b, 2-desamino-10-thia-5,8-dideazafolic acid, 2c, and 2-desamino-10-oxa-5,8-dideazafolic acid, 2d. These compounds were found to be 4-6-fold more cytoxic toward L1210 leukemia cells than their 2-NH2 counterparts and to be poor inhibitors of mammalian thymidylate synthase. However, they were only 1.5-3-fold less inhibitory toward dihydrofolate reductase than the analogous compounds containing a 2-NH2 group. The known thymidylate synthase inhibitors 2-desamino-10-propargyl-5,8-dideazafolic acid and 10-propargyl-5,8-dideazafolic acid were included in this study for purposes of comparison.

Antibodies to HIV-1 in sera from patients with mycobacterial infections

Sera from 478 persons (348 leprosy patients, 33 tuberculosis patients, 29 healthy contacts of leprosy patients, 38 normal healthy Indians, and 30 normal healthy Europeans) were screened for anti-HIV-1 IgG antibodies by ELISA. None was positive. In addition, 132 samples (from 43 leprosy patients, 21 tuberculosis patients, 5 healthy contacts of leprosy patients, 33 normal healthy Indians, and 30 normal healthy Europeans) were also tested by Western blot assay for anti-HIV-1 IgG antibodies. Only 1 of the 63 healthy subjects expressed a prominent p17 band. One or more bands were found in 44 (leprosy patients 33/43, tuberculosis patients 7/21, and leprosy contacts 4/5) of the remaining 69 sera. Antibody to the HIV-1-specific antigen p24 was expressed by 17 of these subjects (14/43 leprosy patients, 1/21 tuberculosis patients, and 2/5 leprosy contacts), either as a single band or in combination with other bands. This raises the possibility of a common antigenic pattern between HIV-1 and mycobacteria, especially Mycobacterium leprae.

Inhibition of murine thymidylate synthase and human dihydrofolate reductase by 5,8-dideaza analogues of folic acid and aminopterin

A series of 5,8-dideaza analogues of folic acid, isofolic acid, aminopterin, and isoaminopterin were evaluated for inhibition of thymidylate synthase, TS, from mouse L1210 leukemia cells with 10-propargyl-5,8-dideazafolic acid, CB3717, 4a, as the reference inhibitor. These compounds were also tested as inhibitors of human dihydrofolate reductase, DHFR, obtained from WIL2 cells. None of the analogues studied were as potent as 4a toward TS; however, 9-methyl-5,8-dideazaisoaminopterin, 6d, was only 2.5-fold less effective. Compound 4a was prepared by direct alkylation of the di-tert-butyl ester of 5,8-dideazafolic acid followed by hydrolysis of the resulting diethyl ester, which resulted from concomitant transesterification. It was found to be identical with a sample of 4a prepared by earlier methodology by using a variety of spectroscopic techniques. Its isomer, 9-propargyl-5,8-dideazaisofolic acid, 4b, which was synthesized by an analogous approach, was found to be dramatically less inhibitory toward TS than 4a. Each of the 2,4-diamino derivatives, including those possessing an allyl or propargyl group at N9, was an excellent inhibitor of DHFR, having a level of potency similar to that of methotrexate, MTX. However, many of these 5,8-dideazaaminopterin analogues were far more inhibitory toward TS than MTX.

Anticonvulsant evaluation of some 3-oxo and 3-thiosemicarbazono analogues of 1-aryl-1-ethylthio-nonanes and related compounds

A number of 3-oxo and 3-thiosemicarbazono analogues of 1-aryl-1-ethylthio-nonanes and related compounds were synthesized. Solutions of the thiosemicarbazones in deuterochloroform were shown by PMR spectroscopy to exist principally in the anti configuration at equilibria except when an ortho-methoxy group was present in the aryl ring. In this case intramolecular hydrogen bonding probably accounts principally for the presence of equal amounts of anti and syn isomers. Evaluation of these compounds for anti-convulsant properties revealed that 1-(2-aminoethylthio)-1-(2-chlorophenyl)nonan-3-one hydrochloride (6a) and sodium 2-(N-acetylamino)-3-[1-(2-chlorophenyl)-3-oxononylthio]propionate (6c) were active and thus they could serve as prototype molecules for future development.

Detection of mycobacterial antigens in leprosy serum immune complex

The antigens from immune complexes of sera from patients with mycobacterial diseases were released by sodium dodecyl sulfate. The antigenic activity of the released proteins was tested by agar gel diffusion and immunoelectrophoresis. This simple method provided direct evidence for the presence of mycobacterial antigens in the immune complexes of sera from patients with leprosy and tuberculosis.

Studies on serum proteins in leprosy by polyacrylamide gel electrophoresis (page)--I

Serum protein pattern was studied in the leprosy spectrum, their contacts and in normal individuals by employing polyacrylamide gel electrophoresis. Sera from 80% of untreated BL/LL, 70% of untreated TT/BT patients and 67% of contacts have shown dysproteinaemia either for 232 kD or for 175 kD or for both these proteins together. Tendency of these proteins to return to normal levels was observed after treatment. But both these proteins come back to normal levels only after subsidence of the disease.

Effect of leprosy sera and foetal calf serum (FCS) on the T cell number of peripheral blood of leprosy patients

Study was conducted in 24 cases of various types of leprosy and 10 healthy controls to find out the effect of various sera on the T cell count of peripheral blood lymphocytes by sheep erythrocyte rosetting method. The percentage of T lymphocytes in lepromatous and tuberculoid cases were significantly lower compared to that in normal healthy controls. All sera except FCS had a stimulatory effect on the number of T cells. The cells incubated for 24 hours in FCS did not show any stimulatory effect on the number of T cells, however, these FCS incubated cells showed a significant elevation in the number of T cells when further incubated in sera either from leprosy cases or from healthy subjects.