Biomedical subjects

Z Ali-Khan

Publications and source records attributed to Z Ali-Khan.

At least 37 records · Page 2Linked to original sources

PubMed1989

Phlogistic and chemotactic activities of alveolar hydatid cyst antigen.

Alveolar hydatid cyst antigen (AHCA) absorbed with Sepharose-coupled anti-mouse Ig or its Sephacryl S-300 fractions was assayed for phlogistic/chemotactic and amyloidogenic properties in C57BL/6J mice. The in vivo and in vitro biological properties of the antigen were assessed by intradermal or intraperitoneal routes in mice or in Boyden chambers, respectively. In both these assays the chemotactic activity of the antigen was found to be dose dependent. A single intradermal injection of the antigen, containing 35 or 70 micrograms protein, showed a peak inflammatory cell response in the dermal layers at 6 hr. Neutrophils were the dominant cellular infiltrates and the number of monocytoid cells, except at 24 hr, remained relatively low. Antigen concentrations ranging from 1 to 200 micrograms protein per Boyden chamber showed peak neutrophilic and monocytoid cell responses with 100 micrograms of the antigen. We therefore conclude that intense inflammatory response and amyloidogenesis in alveolar hydatid cyst-infected murine hosts are directly attributable to the parasite antigen.

Animals↗

PubMed1989

Echinococcus multilocularis: characterization of an alveolar hydatid cyst-induced amyloid enhancing factor.

Alveolar hydatid cysts, the larvae of Echinococcus multilocularis, were shown to induce the formation of an amyloid enhancing-like factor (AEF) called alveolar hydatid cyst-AEF (AHC-AEF) in the spleens of infected animals, 5 to 6 weeks post-infection. The adoptive transfer of AHC-AEF results in rapid induction and deposition of amyloid fibrils in the spleens following AgNO3 injection within 24 h. When injected concomitantly with alveolar hydatid cysts, it shortens the induction phase from 5 or 12 weeks to 1 week in C57BL/6J and A/JAX mice respectively. Preliminary characterization of this factor indicates that its bioactivity may be detected in the non-lipid moiety of spleen cell extracts and the sediment of ultracentrifugation. The factor is resistant to trypsin, pepsin, DNA-ase and RNA-ase treatments. It is sensitive to low or high pH (pH 3.0 and 9.5) and boiling. It resists freeze drying, dialysis, and storage at 4 degrees C for 2 weeks or -70 degrees C for more than a year. It may be fractionated using borate buffered saline, pH 7.4, on Sephacryl S-300 gel column. The active moiety eluted mainly in the first peak.

Amyloid↗

PubMed1988

Evidence for increased amyloid enhancing factor activity in Alzheimer brain extract.

Soluble brain extracts containing 0.1 to 16 mg of protein from 3 normal human brain and 11 patients with Alzheimer's disease, Down's syndrome and other neurological disorders were assayed for amyloid enhancing factor (AEF) activity in the mouse bioassay. At the 0.1 mg dosage, five of seven brain extracts from amyloid-positive samples and only one of four amyloid-negative samples demonstrated AEF activity. Marginal AEF activity was detected in the normal brain extracts at 8 or 16 mg protein dosage. Alzheimer-AEF was aggregated by exhaustive dialysis against 0.01 M phosphate buffer, pH 6 or distilled water and the solubilized aggregate was fractionated on a BioGel P-60 column. Of the two protein peaks, AEF activity was present only in the low mol.wt second fraction, which on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining showed two discrete and three minor peptide bands between 60 and 66 kDa and one of these was periodic acid-Schiff positive, and three fuzzy bands near 14 kDa. Pretreatment of the crude and second fraction with 10 mM phenylmethylsulfonyl fluoride (PMSF) nearly completely abolished the in vivo AEF bioactivity. It is suggested that (a) a higher AEF concentration is present in amyloid-positive brain samples than those negative for amyloid or normal brain tissues, (b) AEF-positive fraction contains at least five dominant peptides ranging between 14 to 66 kDa, and (c) abolition of PMSF-treated Alzheimer-AEF activity, similar to that of murine AEF, might be due to its serine/thiol proteinase nature. To our knowledge, this is the first time that AEF activity has been demonstrated in Alzheimer brain samples.

Adult↗

PubMed1988

Echinococcus multilocularis: relationship between persistent inflammation, serum amyloid A protein response and amyloidosis in four mouse strains.

LPS-hyporesponsive (C3H/HeJ) and LPS-sensitive (C57BL/6, CBA/J, C3H/HeSn) strains of mice were infected intraperitoneally with 50 alveolar hydatid cysts (AHC) to assess the effect of protracted severe inflammation on serum amyloid A protein (SAA) concentrations, splenic amyloid deposition, and pre- and postamyloidotic alterations in the splenic architecture. In general, the SAA concentrations in all the four mouse strains showed a moderate but steady increase throughout the course of infection. Splenic amyloid deposition commenced between 6 to 8 weeks postinfection (p.i.) when the SAA concentrations were relatively low and increased progressively until 12 weeks p.i. when 52 to 78% of the splenic parenchyma was obliterated. CBA mice which harbored the largest AHC throughout the 12-week course of infection showed the poorest SAA and amyloid responses; the situation was reversed in the C3H/HeSn strain. Histologically, most of the splenic follicles, during the stage of maximum amyloid deposition, appeared hypocellular. Their T-cell-dependent periarterial sinuses were either totally depleted of cells or contained plasma cells or myeloid cells. These results show that (a) there is no direct correlation between the intensity of inflammation, SAA concentrations, or amounts of amyloid deposition in either of the four mouse strains and (b) amyloidosis secondary to AHC infection differs from other experimental mouse models of amyloidosis in the magnitude of SAA elevation during the preamyloid phase.

Acute Disease↗

PubMed1988

Biochemical nature and cellular origin of amyloid enhancing factor (AEF) as determined by anti-AEF antibody.

Low ionic strength acidic buffer, Sephadex G-200 and Benzamidine-Sepharose (BZ) gel chromatography, have been used for the partial purification of alveolar hydatid cyst (AHC) induced amyloid enhancing factor (AEF). BZ-gel bound AEF (AEF-BZ) demonstrated AEF activity in the mouse bioassay, proteolytic activity against Hide powder azure showed two major and three minor peptides on SDS-PAGE. Pretreatment of AEF-BZ with 10 mM phenylmethylsulphonyl fluoride or 20 mM p-chloromercuribenzoic acid completely abolished its bioactivity in vivo and proteolytic activity in vitro. Polyclonal anti-AEF antibody (AAA) was generated which on passive transfer into mice completely abolished the bioactivity of both casein-induced, or AHC-induced AEF. The AAA absorbed on Sepharose gel conjugated to normal mouse serum developed one common precipitin band between AE and AEF-positive sera from AHC-infected and old retired mice and in immunostaining it bound to the cytoplasmic granular components of a majority of splenic and peritoneal leucocytes from AHC-infected mice. In contrast, only a few normal mouse leucocytes showed positive staining. We suggest that AEF, in all probability, is a serine/thiol protease of leucocyte origin whose intracellular and humoral concentrations increase significantly during amyloidosis. The role of lysosomal proteases and anti-AEF antibody which has been successfully generated for the first time is discussed with reference to the origin of AEF and its presumed biological function in amyloidogenesis.

Amyloid↗

PubMed1988

Alveolar hydatid cyst induced amyloid enhancing factor (AEF): physicochemical properties and abolition of AEF activity by serine protease inhibitors.

Cell free supernatants prepared from amyloidotic liver, unfractionated and fractionated peritoneal and spleen cells from casein stimulated (16 h post-injection) or alveolar hydatid cyst-infected (7 or 12 weeks post-infection, p. i.) C57BL/6J mice were used to assess amyloid enhancing factor (AEF) activity and to determine its cell-source and physicochemical properties. Of the various supernatants used, the plastic adherent spleen cell lysate (95% macrophages) from 7 weeks p.i mice showed greater AEF activity, on a cell to cell basis, than the lysates prepared from whole spleen cells, peritoneal exudate cells or nonadherent (96% lymphocytes) spleen cells. Culture supernatants obtained from Con A, LPS or the parasite antigen stimulated amyloidotic spleen cells but not the normal mouse spleen cells contained AEF activity; the supernatant from unstimulated amyloidotic spleen cells was negative for AEF activity. AEF was precipitated with 25% and 50% saturation with (NH4)2SO4 and after gel-filtration the low molecular weight fraction contained the AEF activity which on SDS-PAGE resolved into three peptides ranging between mol. wts 15,000 and 31,000. Of the various specific and nonspecific protease inhibitors tested, AEF activity was completely abolished by 30 min preincubation with 10 mM phenylmethylsulphonyl fluoride. Taken together, these results indicate that AEF may be a small molecular weight lysosomal neutral protease of neutrophil/macrophage origin.

Amyloid↗

PubMed1988

Induction of amyloid enhancing factor and its biological properties in murine alveolar hydatidosis.

The biological activity and time of appearance of alveolar hydatid cyst induced splenic amyloid enhancing factor (AEF) with respect to amyloid deposition in the spleens were determined in C57BL/6J mice. Mice were infected intraperitoneally with 100 alveolar hydatid cysts (AHC) and killed bi-weekly between 2 and 14 weeks postinfection (p.i.). AHCs and spleens were excised, weighed and a portion of each spleen was sectioned and stained for quantitation of amyloid deposits and histological studies. The remaining spleen pieces were sonicated separately in cold phosphate buffered saline, pH 7.4 (I g/10 ml), centrifuged (27,000 g, 60 min, 4 degrees C) and the supernatant tested for AEF activity. Splenomegaly followed the progressive increase in the AHC biomass and AEF activity coincided with the appearance of amyloid deposits at 6 weeks p.i. A 2.5 mg intraperitoneal protein dosage of AEF in conjunction with a subcutaneous injection of 0.5 ml of a 0.11 M AgNO3 solution in mice, induced the maximum amount of splenic amyloid deposition at 48 h; the amount of splenic amyloid deposits decreased by either increasing or decreasing the AEF dosage. In vivo, 70% of the AEF activity was abolished by day 4 post-injection of AEF and completely by 3 weeks. These findings indicate that AHC-induced AEF is functionally analogous to casein-induced AEF and its appearance in the spleen coincides with neutrophilia, histiocytosis and amyloid deposition.

Amyloid↗

PubMed1987

Demonstration of amyloid and immune complex deposits in renal and hepatic parenchyma of Alaskan alveolar hydatid disease patients.

Histopathological changes and the incidence of amyloid and immune complex (IC) deposits were examined in six liver (autopsy or biopsy) and two kidney (autopsy) samples from seven Alaskan alveolar hydatid disease (AHD) patients. Both the kidney samples showed evidence of severe nephropathy and glomerular IC deposits. Two of the six liver samples had typical amyloid deposits. All the liver samples examined showed variable amounts of parenchymal atrophy adjacent to the locus of larval Echinococcus multilocularis, periportal and portal fibrosis. Thus secondary amyloidosis and IC-mediated pathological changes should be included as possible complications of AHD.

Adult↗

PubMed1986

Characterization of amyloid protein from mice infected with alveolar hydatid cyst: isolation, purification, and amino acid composition.

The physicochemical properties of alveolar hydatid cyst-induced amyloid (AHCA) were investigated. The AHCA was extracted from spleens, livers, and kidneys of C57BL/6J mice at 12 weeks postinfection and purified on Sephadex G-100 and G-50 gel columns. By using SDS-PAGE and isoelectric focusing techniques the purified AHCA protein showed a molecular weight (MW) of approximately 8,700 and a pI value of 5.3, respectively. The azocasein-induced AA amyloid from C57BL/6J mice had a similar MW but a pI value of 5.8. Unlike mouse AA amyloid, the AHCA was resistant to KMnO4-trypsin treatment, and was shown to cross-react with antisera raised against mouse AA amyloid. The immunologic cross-reactivity between mouse AA, serum amyloid A protein, and AHCA as determined by immunoperoxidase, indirect immunofluorescence, and gel diffusion tests indicated antigenic similarity between AHCA and mouse AA. The amino acid composition of purified AHCA presented both similarities and differences when compared with published data from mouse AA and spontaneously developed mouse amyloid proteins. We report here for the first time the presence of small amounts of methylated basic amino acids and amino sugars in AHCA protein.

Amino Acids↗

PubMed1985

Trypanosoma cruzi: regulation of mitogenic responses during infection in genetically resistant and susceptible inbred mouse strains.

The outcome of Trypanosoma cruzi infection in inbred strains of mice is under genetic control. The lymphocyte responses to T-cell mitogens and their regulation were investigated in strains of mice resistant or susceptible to T. cruzi. Six to eight days after the inoculation of T. cruzi, resistant and susceptible mice had depressed responses to T-cell mitogens. In resistant B6 mice, suppression was maximal 18 days after infection and it persisted for at least 320 days. The duration of immunosuppression correlated with the persistence of a subpatent parasitemia. In cell mixing experiments, it was determined that the concanavalin A (Con A) responses in the resistant B6 and B6C3F1 mouse strains were suppressed by highly active T-suppressor cells. In the susceptible C3H mice, intense suppression of the Con A responses was detected 14 days after inoculation of T. cruzi. Nevertheless, only weak suppressor cell activity was detected in the infected C3H mice, and suppression was not abrogated by passage through a nylon wool column nor by treatment with antitheta antibodies and complement. Thus, it was suggested that, during the course of infection with T. cruzi, splenic T cells from C3H mice acquired a block in the metabolic pathway for cellular activation by Con A. The influences of T. cruzi epimastigotes on the Con A responses of spleen cells from uninfected mice were then studied. The Con A responses of spleen cells from C3H mice were depressed in the presence of epimastigotes, whereas they were either unaffected or enhanced in spleen cells from B6 mice. Hence, the immunoregulatory events provoked by T. cruzi infection differed in genetically resistant and susceptible mice, and lymphocytes from C3H mice were predisposed to a parasite-induced block in the responses to Con A. Thus, the gene(s) determining the outcome of infection with T. cruzi may be phenotypically expressed through an influence on immunoregulatory events.

Animals↗

PubMed1984

Characterization of the inflammatory cells in progressing tumor-like alveolar hydatid cyst. 2. Cell surface receptors, endocytosed immune complexes and lysosomal enzyme content.

Alveolar hydatid cysts (LCM) grow progressively and contribute significantly to the morbidity of hydatid-hosts. To examine whether modifications in immune effector parameters correlate with the pattern of LCM growth, in vivo experiments were carried out in C57BL/6J mice infected intraperitoneally with LCM. Immigrant peritoneal and intra-LCM leukocytes were tested for the loss of cell surface receptors, membrane-bound and internalized immune complexes (ICs) and lysosomal enzyme contents during the restrictive and progressive growth phases of the LCM. The proportion of Fc and C3b receptor-bearing intra-LCM leukocytes decreased 2-fold and 31 to 72% of the leukocytes contained ICs during the progressive phase of the LCM. Acid phosphatase and beta-glucuronidase activities of macrophages declined sharply during the restrictive phase but they gradually increased as the infection progressed. IC-mediated dysfunction of effector leukocytes and modulation of antibody dependent cell cystolysis mechanism are discussed in murine hydatidosis.

Acid Phosphatase↗

PubMed1984

Characterization of the inflammatory cells in progressing tumor-like alveolar hydatid cysts: 1. Kinetics and composition of inflammatory infiltrates.

The kinetics and composition of leukocytic infiltrates from the biphasically growing parasite biomass and the peritonea of C57BL/6J mice infected intraperitoneally with Echinococcus multilocularis cysts were studied. During the first 6 to 8 weeks postinfection (p.i.) the larval cyst masses (LCM) grew slowly, weighted 1 g and contained 3 to 4 X 10(6) leukocytes/100 mg of LCM. Subsequently, (8 to 16 weeks p.i.) the growth of the LCM was rapid and was accompanied by 3 to 4-fold reduction in the absolute leukocyte count; monocytoid cells, neutrophils, eosinophils and T-lymphocyte significantly decreased during the progressive growth phase of the LCM. The cumulative data show a strong inverse relationship between the mean LCM weights and the absolute or relative counts of intra-LCM leukocytes. The data suggest that high concentrations of intra-LCM leukocytes, especially monocytoid cells and to a lesser degree eosinophils, regulate the growth of the LCM in C57BL/6J mice.

Animals↗

PubMed1984

Chronic alveolar hydatidosis and secondary amyloidosis: pathological aspects of the disease in four strains of mice.

Amyloidogenic potentials of alveolar hydatid cyst, the larval stage of Echinococcus multilocularis, were studied in BALB/c, C57BL/6J, CBA/J and A/JAX strains of mice. To determine strain susceptibility and sensitivity of various soft organs to amyloidosis, the intensity of inflammation and mean weights of the larval cyst masses from each host strain were correlated at various time intervals postinfection (p.i.) with the onset and amount of splenic, hepatic and kidney amyloid deposits. The onset and incidence of amyloidosis in these four host strains corresponded with the intensity of hepatic inflammation and not with the load of the parasite biomass. Hydatid mice spleens were more sensitive to amyloid deposition than livers or kidneys. Splenic amyloid deposits appeared at 6 weeks p.i. in BALB/c and C57BL/6J mice and at 8 and 12 weeks p.i. in CBA/J and A/JAX mice, respectively. The latter strain was relatively resistant to hydatid-induced amyloidosis. At 12 weeks p.i., amyloid-mediated changes in the spleens, livers and kidneys of the susceptible host strains were much more severe than in the A/JAX strain. In conclusion, alveolar hydatid cyst is highly amyloidogenic and provides a promising substitute for the study of induction and pathogenesis of secondary amyloidosis.

Amyloidosis↗

PubMed1983

Cystolytic events and the possible role of germinal cells in metastasis in chronic alveolar hydatidosis.

Two and six week old alveolar cysts of Echinococcus multilocularis were isolated from C57BL/6J and Balb/cJ mice and used to study the cystolytic events mediated by resident inflammatory cells. Ultramicroscopic degenerative changes in these cysts were compared with the ultrastructure of in vitro grown cysts (free of inflammatory cells). Macrophages, eosinophils and neutrophils were found to bind to the laminated layer of plasma membrane of the germinal layer of cysts. Hydrolytic enzymes and eosinophil granules released extracellularly from inflammatory cells at the cyst surface appear to dissolve the laminated layer and produce gaps in the plasma membrane. Macrophages actively phagocytose the granular ground substance of the disintegrated laminated layer. Cystolysis results in the release of germinal cells which measure 6-17 microns, possess nuclei with prominent nucleoli, sparse endoplasmic reticulum, Golgi complexes and oval mitochondria. Based on histologic evidence we believe that germinal cells may be the progenitors of cysts. The possibility that germinal cells may give rise to distant metastatic foci of alveolar cysts, in immunocompromised hosts, is discussed.

Animals↗

PubMed1983

Granular and globular acid alpha-naphthyl-acetate-esterase staining pattern of resting and mitogen-activated murine lymphocytes.

Available methods for the identification of T-lymphocytes in tissue sections and in single cell suspensions are often tedious and require a lot of manipulation. Here we confirm previous findings that nonspecific alpha-naphthyl-acetate esterase (ANAE) is a reliable method for the identification of resting thymus-derived lymphocytes but not for concanavalin-A-stimulated lymphocytes, as a small proportion of lipopolysaccharide-stimulated lymphoblasts exhibit ANAE activity as well. We have also shown that there is a relationship between the globular staining pattern and the degree of cell activation. Finally, we noted that prolonged incubation of lymphocytes at 37 degrees C reduces the number of ANAE-positive cells.

Animals↗

PubMed1983

Immune complexes in experimental alveolar hydatidosis.

Increasing amounts of immune complexes (IC) accumulated in the blood of C57BL/6J (H-2b) mice infected for 16 weeks with alveolar hydatid cysts. The circulating IC were detected both quantitatively (precipitation with 3.75% polyethylene glycol) and qualitatively (Raji cell binding assay) in the sera of hydatid-mice. The levels of serum IC roughly parallel the increase in weight of the larval cyst masses (LCM) and were inversely reacted to serum compliment activity; the latter was markedly reduced at 14 weeks postinfection. The solubilized serum IC was reacted with appropriate antisera in gel precipitation test; it consisted of E. multilocularis antigens, IgGl, IgG2b, IgM and C3. Mouse IgG, IgM, complement and hydatid antigens were also detected by the indirect immunofluorescent technique in kidney sections of hydatid-mice infected 14 weeks before. The role of IC is discussed with reference to immunodepression and growth of the LCM in hydatid mice.

Animals↗

PubMed1983

Murine alveolar hydatidosis: a potential experimental model for the study of AA-amyloidosis.

Histochemical and immunohistologic evidence has been presented to characterize the AA-type of amyloidosis in C57BL/6J (H-2b) mice infected i.p. with 50 cysts of Echinococcus multilocularis. Congo red-stained sections of kidneys and spleens from 4 weeks postinfected (p.i.) hydatid-mice were negative for the amyloid deposits. Heavy amyloid deposits, which in ultrathin sections of kidneys measured 8-12 nm in thickness, obliterated the perifollicular sinuses in spleens and glomerular capillaries in kidneys at 16 weeks p.i. Amyloid deposits were resistant to potassium permanganate treatment. They bind strongly to rabbit anti-mouse AA serum (RAA) as demonstrated by using peroxidase-anti-peroxidase technique. Preabsorption of RAA with azo-casein induced amyloid abolished completely the binding of RAA to mouse AA and hydatid-mouse deposits. Rabbit monospecific mouse antisera to heavy and light chains of Igs did not bind to amyloid deposits in hydatid-mice kidneys. Enumeration of spleen cells from the 16 weeks p.i. amyloidotic spleens showed a significant reduction in the total lymphocytes and T-cells. Overt accumulation of amyloid deposits in the spleen was associated with its disorganization, a significant reduction in T-cells and the depressed response of spleen cells to ConA and LPS mitogens. The relationship between proliferating alveolar hydatid cyst, intense inflammatory response, depressed cell mediated immunity and AA-type of amyloidosis is discussed in murine hydatidosis.

Amyloidosis↗

PubMed1983

Intraperitoneal murine alveolar hydatidosis: relationship between the size of the larval cyst mass, immigrant inflammatory cells, splenomegaly and thymus involution.

Both phagocytic and nonphagocytic inflammatory cells infiltrate the peritoneal cavity of mice infected intraperitoneally with Echinococcus multilocularis cysts. A longitudinal study on the kinetics of peritoneal leukocytosis at 3 days, 1, 2, 3, 4, 6, 8, 10 and 14 weeks postinfection revealed that the restrictive and progressive growth phases of the alveolar hydatid cyst correspond sharply with the increasing and decreasing levels of peritoneal cells, respectively. The restrictive phase is characterized by the progressive peritoneal accumulation of lymphocytes, monocytoid cells and eosinophils. Between 6 and 14 weeks p.i., the alveolar cyst increased in weight 30 fold. This phase was associated with peritoneal neutrophilia, splenomegaly, involution of the thymus and a significant decline in the extravasated lymphocytes, monocytoid cells and eosinophils. These results in conjunction with our previous studies indicate that host's hydatid immunosurveillance is compromised as a result of profound immunopathologic disorders during the progressive growth phase of the alveolar cyst. In order to understand the prolonged survival of alveolar cyst, further investigation of inflammatory cell-cyst interactions is indicated.

Animals↗