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PubMed1999

Modified milk fat reduces plasma triacylglycerol concentrations in normolipidemic men compared with regular milk fat and nonhydrogenated margarine.

BACKGROUND: A modified milk fat with reduced cholesterol was developed by fractionation technology. OBJECTIVE: The effect of this modified milk fat on the lipoprotein profile of 21 normolipidemic men was compared with that of regular milk fat and nonhydrogenated margarine. DESIGN: A crossover design was used for the administration of the 3 experimental diets, which provided 13240 kJ as 16% protein, 51% carbohydrates, 33-34% lipids, and 21 g fiber/d. The ratio of polyunsaturated to saturated fat was 1.3:1 for the margarine diet and 0.3:1 for the milk-fat diets. The cholesterol content of the modified milk-fat and margarine diets was similar (248 and 254 mg/d, respectively), but was significantly higher (428 mg/d) for the regular milk-fat diet. RESULTS: Modified and regular milk fats did not change plasma total and LDL cholesterol significantly, but margarine did (P < 0.01). Furthermore, modified milk fat maintained initial HDL(2)-cholesterol concentrations, but margarine reduced this variable significantly (P < 0.05). These results can be explained by the lower ratio of polyunsaturated to saturated fat in the modified and regular milk-fat diets than in the margarine diet. Men who ingested modified milk fat had significantly (P < 0.05) lower total and VLDL-triacylglycerol and VLDL-cholesterol concentrations than did those who ingested either regular milk fat or margarine. This may have been, in part, because of the lower intestinal fat absorption with modified milk fat than with regular milk fat and margarine arising from changes in the melting properties of milk fat with fractionation. CONCLUSION: A reduction in plasma triacylglycerol concentrations after the consumption of modified milk fat may prevent the onset of hypertriacylglycerolemia.

Adult↗
PubMed1995

Determination of stereospecificity of benzo[a]pyrene diolepoxide-DNA antisera with site-specifically modified oligonucleotides.

Antisera developed against benzo[a]pyrene diolepoxide (BPDE)-DNA adducts are sensitive tools for detection of DNA adducts in human samples. All antisera currently used for biomonitoring studies were produced against DNA or guanosine modified with racemic anti-BPDE. Using a non-competitive enzyme-linked immunosorbent assay (ELISA), Venkatachalam and Wani (Carcinogenesis, 15, 565-572, 1994) recently tested polyclonal and monoclonal (5D2) antisera for cross-reactivity against oligonucleotides containing (+)-and (-)-trans-anti-BPDE-N2-guanine or N6-adenine adducts and showed different stereospecificity for the two antisera. Because of the importance of antiserum specificity in human biomonitoring studies, we have tested several monoclonal (Mab 5D11 and 5D2) and polyclonal (Pab #29) antisera developed against racemic anti-BPDE-DNA adducts, and Mab 8E11 developed against anti-BPDE-guanosine adducts. Stereoisomeric anti-BPDE-modified oligonucleotide adducts in the sequence 5'-d(CC-AT-CG*CTACC)-3' where G* = anti-BPDE-N2-dG with (+)-trans, (-)-trans, (+)-cis and (-)-cis adduct stereochemistry at the C10 position of anti-BPDE were tested by competitive ELISA. Two structurally related 5-methylchrysene diolepoxide adducts with G* = (+)- and (-)-trans-anti-5-MeCDE-N2-dG in the same oligonucleotide were also tested. While Mab5D2 had the highest affinity for the (-)-trans-anti-BPDE-modified oligomer, Mab 5D11 and 8E11 and Pab #29 recognized the (+)-trans-anti-BPDE-modified oligomer better than the (-)-trans-anti-BPDE modified oligomer. Mab 5D11 and Pab #29 recognized racemic anti-BPDE-modified DNA adducts better than trans-anti-BPDE-modified oligonucleotides; however, Mab 8E11 showed similar sensitivity to racemic anti-BPDE-DNA adducts and (+)- and (-)-trans-anti-BPDE-modified oligomers. All antisera exhibited lower reactivities with both 5-MeCDE modified oligomers. Because of their sensitive detection of (+)-trans-anti-BPDE-dG adducts, the primary adduct produced in vivo, Mab 8E11 and 5D11 and Pab #29 are appropriate for measurement of most adducts formed in humans.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1972

Dominance modifiers in neurospora crassa: phenocopy selection and influence of certain ascus mutants.

When homozygous in zygotes, mutant alleles at the peak locus in linkage group V of Neurospora crassa initiate aberrant asci that are nonlinear, in contrast to the linear asci characteristic of wild type. Most mutant alleles are recessive, inasmuch as crosses of the mutant strains with wild type give linear asci. However, five different mutant alleles, when heterozygous with the wild-type allele, act in varying degrees as zygote dominants, initiating both linear and nonlinear asci, the relative proportions depending on the allele. Five modifiers that act on the dominance relationships of at least one of the five possible heterozygotes of a dominant peak and its wild-type allele have been characterized, four of them having been obtained by selection directed against a phenocopy of these mutants induced by treatment of wild type with l-sorbose. The pattern of modifier specificity observed among the various dominant peak heterozygotes indicates that the phenotypic effects are produced by a complex relationship between the modifiers and the dominant peak alleles in relation to their wild-type allele. In all but two cases the direction of modification, where present, is towards decreasing the dominance of the mutant allele in the heterozygote, evidenced by an increase in the percentage of linear asci when compared with control data. The modifiers exert their maximum modification when they themselves are heterozygous with their wild-type alleles and when the dominant peak allele is heterozygous with its wild-type allele. No modification occurs when heterozygous modifiers are included in zygotes homozygous for a dominant peak allele, reinforcing the notion that the modifiers act on the dominance relationship existent between a dominant peak allele and its wild-type allele, rather than influencing some activity of the mutant allele itself. The modifiers have no detectable effect of their own on ascus morphology, since homozygous modifier zygotes initiate entirely linear asci when only wild-type alleles of peak are present in the zygotes. Their only detectable effect, other than dominance modification, appears to be in conferring sorbose resistance to the mycelium. The modifiers are unlinked to the peak locus, and, except for two of them, they are nonallelic.

Crosses, Genetic↗
PubMed2004

A modified vitamin regimen for vitamin B2, A, and E administration in very-low-birth-weight infants.

INTRODUCTION: Very-low-birth-weight (VLBW; birth weight, <1,500 g) infants receive preterm infant formulas and parenteral multivitamin preparations that provide more riboflavin (vitamin B2) than does human milk and more than that recommended by the American Society of Clinical Nutrition. VLBW infants who are not breast-fed may have plasma riboflavin concentrations up to 50 times higher than those in cord blood. The authors examined a vitamin regimen designed to reduce daily riboflavin intake, with the hypothesis that this new regimen would result in lower plasma riboflavin concentrations while maintaining lipid-soluble vitamin levels. METHODS: Preterm infants with birth weight < or =1,000 g received either standard preterm infant nutrition providing 0.42 to 0.75 mg riboflavin/kg/day (standard group), or a modified regimen providing 0.19 to 0.35 mg/kg/day (modified group). The modified group parenteral vitamin infusion was premixed in Intralipid. Enteral feedings were selected to meet daily riboflavin administration guidelines. Plasma riboflavin, vitamin A, and vitamin E concentrations were measured weekly by high-performance liquid chromatography. Data were analyzed with the independent t test, chi, and analysis of variance. RESULTS: The 36 infants (17 standard group, 19 modified group) had birth weight and gestational age of 779 +/- 29 g and 25.5 +/- 0.3 weeks (mean +/- SEM) with no differences between groups. Modified group infants received 38% less riboflavin (0.281 +/- 0.009 mg/kg/day), 35% more vitamin A (318.3 +/- 11.4 microg/kg/day), and 14% more vitamin E (3.17 +/- 0.14 mg/kg/day) than standard group infants. Plasma riboflavin rose from baseline in both groups but was 37% lower in the modified group during the first postnatal month (133.3 +/- 9.9 ng/mL). Riboflavin intake and plasma riboflavin concentrations were directly correlated. Plasma vitamin A (0.222 +/- 0.022 microg/mL) and vitamin E (22.26 +/- 1.61 /mL) concentrations were greater in the modified group. CONCLUSIONS: The modified vitamin regimen resulted in reduced riboflavin intake and plasma riboflavin concentration, suggesting plasma riboflavin concentration is partially dose dependent during the first postnatal month in VLBW infants. Modified group plasma vitamin A and vitamin E concentrations were greater during the first month, possibly because the vitamins were premixed with parenteral lipid emulsion. Because of the complexity of this protocol, the authors suggest that a parenteral multivitamin product designed for VLBW infants which uses weight-based dosing should be developed.

Analysis of Variance↗
PubMed1995

A modified directional atherectomy catheter for resection of calcified atherosclerotic plaques.

BACKGROUND: The purpose of this study was to determine the feasibility of resecting calcified atherosclerotic plaques in human cadaveric vessels by using a modified directional coronary atherectomy catheter and to correlate these results with bench tests using an in-vitro sea coral model. METHODS: The conventional directional coronary atherectomy catheter was modified by changing the cutter blade to a tungsten carbide material and by increasing the torsional strength of the drive cable. The performance of the modified directional coronary atherectomy (DCA) catheter was compared with the conventional catheter using a sea coral model to simulate calcified material. Then, 10 human ex-vivo arteries (eight with calcification) were treated with both conventional and modified catheters, and the results studied with intravascular ultrasound and confirmed by histologic examination. RESULTS: Using the modified directional coronary atherectomy catheter it was possible to perform effective and consistent longitudinal cutting, and to resect a significantly larger amount of coral (1.0 +/- 0.1 mm2 versus 0.2 +/- 0.1 mm2 with conventional cutter, P < 0.0001). In heavily calcified ex-vivo arteries, the modified catheter was more effective in removing calcified plaques (13 +/- 11 mg versus 3.7 +/- 1.4 mg with conventional cutter, P = 0.07). Intravascular ultrasound confirmed the effective atherectomy (residual area stenosis 28 +/- 16% versus 47 +/- 10% with the conventional device, P < 0.05), and histologic examination showed calcified nodules in the atherectomy samples obtained with the modified cutter (area of calcium 1.43 +/- 0.89 mm2 versus 0.93 +/- 0.83 mm2 with the conventional cutter). CONCLUSIONS: The modified directional coronary atherectomy catheter effectively removed both non-calcified and calcified plaques in the ex-vivo human cadaveric arteries, thus demonstrating the feasibility of directional coronary atherectomy of calcified plaques. This modified device shows promise for treating calcified coronary lesions, especially in larger vessels.

Animals↗
PubMed1978

Studies on delayed hypersensitivity to protein antigen. Induction of delayed hypersensitivity by chemically modified antigen.

it was shown in our previous paper that mice primed with chemically modified bacterial alpha-amylase (BaA), which was neither cross-reactive with anti-BaA antibody nor able to induce a humoral anti-BaA response, developed enhanced responses to a subsequent challenge with native BaA and that the magnitude of the immunological memory was closely related to the priming dose of modified BaA. This paper describes the experimental conditions for induction of delayed hypersensitivity (DH) by modified BaA in relation to the development of immunological memory for antibody response to native BaA. Mice primed with either an intraperitoneal (i.p.) or subcutaneous (s.c.) injection of modified BaA in complete Freunds adjuvant (CFA) developed enhanced anti-BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to a subsequent challenge with BaA. In contrast, when mice were immunized with an s.c. injection of the modified BaA only, a significant level of DH to native BaA could be induced, as measured by the footpad reaction (FPR). The highest degree of DH was observed in mice given 50 micrograms of modified BaA. DH was detectable within 5 days and persisted for 25 days after immunization. In the reciprocal combination of native BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to DH was examined. The primary anti-BaA responses induced by an i.p. injection of large doses of BaA was markedly higher than those induced by an s.c. injection, while DH was exhibited only in mice given s.c. injection of BaA in CFA. With respect to DH to native BaA induced by the modified BaA, it was shown that C3H/He mice were high and C57BL/6 mice were low responders.

Amylases↗
PubMed1982

Induction of cell-mediated cytotoxic self responses by epidermal cells modified with a haptenic sulphydryl reagent.

Murine epidermal cells (EC) act as stimulator cells in the generation of allogeneic cytotoxic T lymphocytes (CTL) in cell-mediated lympholysis (CML) and are suitable targets for allogeneic and hapten-self CTL. To analyse the role of EC in the generation of and recognition by anti-self CTL, syngeneic hapten-modified murine EC were used as in vivo and in vitro stimulating populations and as target cells in a hapten-self CML system. Epidermal cells were modified with the sulphydryl-reactive haptenic reagent N-iodoacetyl-N'-(5-sulphonic-1-naphthyl)ethylenediamine (I-AED). C3H.SW (H-2b) AED-self CTL responses were generated by stimulation with syngeneic AED-modified EC and were readily demonstrated when tested on syngeneic hapten-modified EC. These CML responses were hapten-specific and H-2 restricted. No substantial difference was detected in the ability of AED-modified EC and spleen cells (SC) to stimulate the generation of secondary AED-self CTL. Cold target inhibition experiments with hapten-modified EC and SC blockers did not reveal tissue-specific recognition of hapten-modified EC or SC targets by AED-self CTL. These findings demonstrate that hapten-modified EC, when used for priming in vivo and subsequently for in vitro sensitization, can induce hapten-specific self CTL that are reactive against syngeneic hapten-modified EC.

Animals↗
PubMed1997

Evaluation of residual neuromuscular blockade using modified double burst stimulation.

BACKGROUND: To assess the degree of residual neuromuscular blockade, double burst stimulation (DBS) is commonly applied in the clinical setting. However, fades in response to DBS3,3 can rarely be identified manually when train-of-four (TOF) ratios are > or = 0.70, and, in contrast, fades in response to DBS3,2 are felt manually in an undesirably high proportion of cases, even at TOF ratios greater than 0.7. We investigated whether a new monitoring method, modified DBS, would be useful to determine an adequate degree of recovery from neuromuscular blockade. For modified DBS, two burst stimuli were applied at an interval of 750 ms. The first stimulation in the modified DBS consisted of two stimuli of 0.3 ms duration at 50 Hz and the second of two stimuli of 0.2 ms duration at 50 Hz. METHODS: Forty-five adult patients undergoing elective nitrous oxide-oxygen-isoflurane anesthesia were randomly divided into one of three groups: DBS3,3 group (n = 15), DBS3,2 group (n = 15), or modified DBS group (n = 15). During recovery from vecuronium-induced neuromuscular blockade, on both forearms, DBS3,3, DBS3,2, and modified DBS were delivered in the DBS3,3 group, DBS3,2 group, and modified DBS group, respectively. One hand and forearm (fixed arm) were immobilized to quantify the degree of neuromuscular blockade mechanically, and the contralateral arm (free arm) was unrestrained. An observer determined tactiley on the free arm the presence or absence of fade in response to the three DBS patterns. RESULTS: Probabilities of detection of fade in response to the DBS3,3 were 67% (TOF ratio of 0.51-0.60), 40% (0.61-0.70), 19% (0.71-0.80), 5% (0.81-0.90), and 0% (0.91-1.00). Those to the DBS3,2 were 95% (0.51-0.60), 93% (0.61-0.70), 83% (0.71-0.80), 65% (0.81-0.90), and 38% (0.91-1.00). Those to modified DBS were 90% (0.51-0.60), 86% (0.61-0.70), 65% (0.71-0.80), 25% (0.81-0.90), and 3% (0.91-1.00). Those modified DBS was more sensitive in diagnosing residual neuromuscular blockade than DBS3,3 at the TOF ratio of 0.51-0.90, but was less sensitive than DBS3,2 at the TOF ratio of 0.81-1.00 (P < 0.05). CONCLUSION: Our results indicate that the modified DBS may be a useful stimulation pattern to diagnose the adequacy of recovery from neuromuscular blockade.

Adult↗
PubMed1992

Modified latex agglutination test for antibodies to Toxoplasma gondii in eluates from Guthrie cards.

AIMS: To determine whether the Eiken particle agglutination test could be modified to make it sufficiently sensitive to screen blood samples collected on Guthrie cards for the presence of antibodies to Toxoplasma gondii; to evaluate the specificity of the modified system; and to compare seroepidemiological data on the prevalence of T gondii in pregnant women. METHODS: Simulated dried blood spots were prepared from sera from pregnant women booking for antenatal care. Eluates from the simulated dried blood spot cards and sera were tested in parallel using the modified test (1 in 5 dilution of latex) and the standard assay (neat latex particles) and endpoints determined. Guthrie card eluates, from neonates in three Thames regions, were then tested using the modified test. RESULTS: The modified test produced a 4.21-fold increase in antibody titre in 85 sera when tested in parallel with the standard test. Eluates of 168/170 from simulated dried blood spots derived from seropositive patients gave a positive result in the modified test. The two eluates which gave a negative result were derived from patients with an equivocal titre of 1/16 in the standard serum test. Of the eluates derived from serum negative patients all 103 were negative at a dilution of 1 in 4 in the modified test. The seroprevalence of antibodies to T gondii in pregnancy was 21.8% using the standard test. A similar value of 20.5% was obtained when dried blood spots from neonates in a similar region of London were tested by the modified test. CONCLUSIONS: The modified Eiken Toxo-reagent test is sensitive, simple, and economic for screening large numbers of dried blood spots. The procedure could be easily semiautomated and the technique applied to the mass screening of neonatal blood samples collected on Guthrie cards to determine the seroprevalence of T gondii in pregnant women.

Animals↗
PubMed1996

Blockade of lysophosphatidylcholine-modified cardiac Na channels by a lidocaine derivative QX-222.

Single Na channels from rat and rabbit ventricular cells were studied with use of the excised inside-out patch-clamp technique. To investigate local anesthetic interactions with Na channels modified by the ischemic metabolite lysophosphatidylcholine (LPC), the quaternary ammonium lidocaine derivative QX-222 [2-(trimethylamino)-N-(2,6-dimethylphenyl)acetamide] was applied to the cytoplasmic side of patches from untreated cells and from those treated with LPC for approximately 1 h. Single-channel amplitudes and kinetics for unmodified channels were similar to those reported previously for cardiac cells with a single-component, mean-channel open time. LPC-modified channels showed prolonged open channel bursting with a two-component, mean open time, suggesting two open states. Conductance sublevels to the 60-70% level of the main conductance were found in both unmodified and LPC-modified channels and also with and without QX-222 present. QX-222 reversibly shortened the open time of the unmodified channel and for both open times of the LPC-modified channel without decreasing single-channel amplitude. Calculated association rates for QX-222 with the channel were found to be greater for the open states of the modified channel than those for the unmodified channel. Thus the lidocaine analogue QX-222 interacts with and blocks the open state of both unmodified and LPC-modified, cardiac Na channels. The blocking effect on LPC-modified channels would be predicted to be greater both because of the longer dwell time in the high-affinity open states for modified channels and also because of an intrinsically greater association rate in the modified channels.

Animals↗
PubMed2004

Definition of the immunogenic forms of modified human LDL recognized by human autoantibodies and by rabbit hyperimmune antibodies.

Humans and laboratory animals recognize human modified LDL as immunogenic. Immune complexes (ICs) isolated from human sera contain malondialdehyde-modified LDL (MDA-LDL) and N (epsilon)(carboxymethyl)lysine-modified LDL (CML-LDL) as well as antibodies reacting with MDA-LDL, copper-oxidized LDL (OxLDL), CML-LDL, and advanced glycosylation end product (AGE)-modified LDL. OxLDL and AGE-LDL antibodies isolated from human sera recognize the same LDL modifications and do not react with modified non-LDL proteins. Rabbit antibodies have different reactivity patterns: MDA-LDL antibodies react strongly with MDA-LDL and MDA-BSA but weakly with OxLDL; OxLDL antibodies react strongly with OxLDL and weakly with MDA-LDL; CML-LDL antibodies react with CML-LDL > CML-BSA > AGE-LDL > OxLDL; AGE-LDL antibodies react strongly with AGE-LDL, react weakly with OxLDL, and do not react with CML-LDL. Thus, human and rabbit antibodies seem to recognize different epitopes. Capture assays carried out with all rabbit antibodies showed binding of apolipoprotein B-rich lipoproteins isolated from ICs, suggesting that laboratory-generated epitopes are expressed by in vivo-modified LDL, although they are not necessarily recognized by the human immune system. Thus, the definition of immunogenic forms of modified LDL eliciting human autoimmune responses requires the isolation and characterization of autoantibodies and modified LDL from human samples, whereas rabbit antibodies can be used to detect in vivo-modified human LDL.

Animals↗
PubMed1989

Platelet-modified low density lipoprotein induces macrophage cholesterol accumulation and platelet activation.

Low density lipoprotein (LDL), modified by chemical or biological means, was shown to induce macrophage cholesterol accumulation. The cholesterol and protein contents of LDL were decreased (by 10 and 15%, respectively) by incubation of the LDL for 2 h at 37 degrees C with normal washed platelet suspension or with platelet-conditioned medium; these decreases were not affected by platelet activation. The platelet-modified LDL caused a greater increase (by up to 15%) in collagen-induced, in vitro platelet aggregation than control LDL. Incubation of mouse peritoneal macrophages with platelet-modified LDL for 18 h at 37 degrees C resulted in an elevation of the macrophage cholesterol ester content (by 35-50%) as well as an increase in the cholesterol esterification rate (by 40-70%), compared with the effect of control LDL. Macrophage cholesterol synthesis, however, was significantly decreased (by 40-50%), compared with the effect of control LDL. The effect of LDL treated by platelet-conditioned medium was similar to that of platelet-modified LDL. The effect of platelet-modified LDL on macrophage cholesterol esterification was maximal within 24 h of incubation, and it was not significantly affected by inhibition of cholesterol synthesis. The platelet-modified LDL was taken up by the macrophages in a saturable fashion and its uptake was competitively inhibited by LDL, but not by acetylated LDL. We conclude that platelet-modified LDL interacts with the LDL receptor and induces macrophage cholesterol accumulation. Since the modified lipoprotein induces in vitro foam cell formation and platelet activation, platelet-modified LDL could be considered to be pro-atherogenic.

Animals↗
PubMed2000

Increased uptake of alpha-hydroxy aldehyde-modified low density lipoprotein by macrophage scavenger receptors.

Reactive aldehydes can be formed during the oxidation of lipids, glucose, and amino acids and during the nonenzymatic glycation of proteins. Low density lipoprotein (LDL) modified with malondialdehyde are taken up by scavenger receptors on macrophages. In the current studies we determined whether alpha-hydroxy aldehydes also modify LDL to a form recognized by macrophage scavenger receptors. LDL modified by incubation with glycolaldehyde, glyceraldehyde, erythrose, arabinose, or glucose (alpha-hydroxy aldehydes that possess two, three, four, five, and six carbon atoms, respectively) exhibited decreased free amino groups and increased mobility on agarose gel electrophoresis. The lower the molecular weight of the aldehyde used for LDL modification, the more rapid and extensive was the derivatization of free amino groups. Approximately 50-75% of free lysine groups in LDL were modified after incubation with glyceraldehyde, glycolaldehyde, or erythrose for 24-48 h. Less extensive reductions in free amino groups were observed when LDL was incubated with arabinose or glucose, even at high concentration for up to 5 days. LDL modified with glycolaldehyde and glyceraldehyde labeled with (125)I was degraded more extensively by human monocyte-derived macrophages than was (125)I-labeled native LDL. Conversely, LDL modified with (125)I-labeled erythrose, arabinose, or glucose was degraded less rapidly than (125)I-labeled native LDL. Competition for the degradation of LDL modified with (125)I-labeled glyceraldehyde was nearly complete with acetyl-, glycolaldehyde-, and glyceraldehyde-modified LDL, fucoidin, and advanced glycation end product-modified bovine serum albumin, and absent with unlabeled native LDL. These results suggest that short-chain alpha-hydroxy aldehydes react with amino groups on LDL to yield moieties that are important determinants of recognition by macrophage scavenger receptors.

Aldehydes↗
PubMed2002

Comparison of immunohistochemical and modified Giemsa stains for demonstration of Helicobacter pylori infection in an African population.

BACKGROUND: Modified Giemsa staining has been favoured by many researchers because it is easy to perform but, like many other stains, demonstration of the bacteria depends on its morphology. It has been arged in some research circles that some of the organisms in the gastric mucosa may not be true H.pylori. Immunohistochemical techniques have been developed and make use of anti H.pylori antibody, which reacts, with somatic antigens of the whole bacteria and have been found to correlate well with the presence of the bacteria. OBJECTIVE: To ascertain the efficacy of modified Giemsa stain in an African setting where H.Pylori seems quite prevalent. STUDY DESIGN: A laboratory-based study of two diagnostic tests in which modified Giema stain was compared with immunohistochemistry. METHODS: A total of 48 consecutive autopsy cases with no upper gastro intestinal diseases had their gastric mucosa stained for demonstration of H.pylori using both modified Giemsa and immunohisto chemical staining techniques. RESULTS: Twenty-seven cases of H.pylori were demonstrated by both techniques and 14 cases were not identified by the two staining methods. In 2 cases immunostain could not demonstrate the bacteria but they were identified with modified Giemsa stain while in 5 cases the bacteria were identified by immunostain but not with modified Giemsa stain. The sensitivity of modified Giemsa stain was 85% (CI 66.5-98.8) while the specificity was 89% (CI 60.4 - 97.8). The positive predictive value of modified Giemsa stain was 93% CI 75 - 98.8%) while the negative predictive value was 74% (CI 48.6 - 89.9). The kappa statistic comparing the 2 stains was 0.69 (p value 0.00001) giving a good agreement between the two tests. CONCLUSION: With the above results the modified Giemsa stain, which is readily available in most African laboratories, is recommenced for diagnosis of H.pylori, a prevalent infection in Africa.

Adolescent↗
PubMed1992

Immunization of colorectal cancer patients with modified ovine submaxillary gland mucin and adjuvants induces IgM and IgG antibodies to sialylated Tn.

Tn and sialylated Tn (sTn) are blood group-related epitopes expressed on mucins of colon carcinoma and other epithelial tumors and are, therefore, potential targets for immunological control. We have immunized 20 colorectal cancer patients at high risk for recurrence with a vaccine consisting of partially desialylated ovine submaxillary gland mucin (modified OSM) which contains both Tn and sTn determinants. Six patients were treated with modified OSM alone (group 1), eight patients were treated with modified OSM and the immunological adjuvant DETOX (group 2), and six patients were treated with modified OSM and Bacillus Calmette-Guérin (group 3). Pre- and postvaccination sera were tested by enzyme-linked immunosorbent assay and dot blot immune stains for antibodies reactive with modified OSM. Antibody titers increased in 4 of 8 patients immunized with modified OSM and DETOX, in 5 of 6 patients immunized with modified OSM and B. Calmette-Guérin, and in 0 of 6 patients receiving modified OSM without adjuvant. The specificity of induced IgM and IgG antibodies was confirmed by demonstrating reactivity with OSM, bovine submaxillary mucin, and synthetic glycoconjugates sTn-human serum albumin (HSA) and Tn-HSA in enzyme-linked immunosorbent assay and immune stains. Median IgM pre-postvaccination reciprocal titers were 20/80 for Tn-HSA and 10/320 for sTn-HSA. Low level IgG antibody titers against sTn-HSA were detected after vaccination in 7 patients. Toxicity was limited to inflammatory skin reactions at the site of vaccination resulting from the adjuvants. No inflammatory infiltrates were seen in the skin when the modified OSM vaccine was administered in the absence of an immunological adjuvant. These results demonstrate that sTn and Tn can be recognized by the human immune system and that vaccines containing these structures can be administered safely with immunological adjuvants. Attempts to augment the immunogenicity of these carbohydrate antigens by covalent attachment to immunogenic carrier proteins and the use of more potent immunological adjuvants are now being pursued.

Adjuvants, Immunologic↗
PubMed2004

Gene modifiers in pediatrics: application to cystic fibrosis.

Human disease is a result of interactions between each person's genetic program and the environment. Individual genes responsible for many pediatric diseases have been discovered, but there is still considerable variability in phenotype within a given disorder. While some of the variability is undoubtedly caused by environmental factors, genes other than the primary disease gene likely modify phenotypes. These gene modifiers alter the effects of the primary disease gene and therefore result in phenotypic variability. Studying gene modifiers will therefore likely lead to a better understanding of pathophysiology and to development of new treatments. Statistical and genetic methods used to identify gene modifiers range from simple association studies to complex family studies, each with its own strengths. The search for gene modifiers in cystic fibrosis (CF), a common mendelian disorder, provides a good example of an application of the latest approaches. Potential modifiers of CF are chosen to reflect the known pathophysiology of CF, including genes involved in the host response to infection and CF complications such as intestinal obstruction, diabetes, and liver disease. A region on chromosome 19 that modifies intestinal obstruction in CF has been identified based on a region of synteny in the mouse; however, the specific gene has not been completely characterized. While a number of other putative gene modifiers have been investigated in CF, none are clearly substantiated. To date, only a few gene modifiers in pediatric disease have been conclusively identified, but we believe that future research will open the doors for new knowledge and treatment.

Animals↗
PubMed1997

A comparison of modified cytological and histological staining methods for the diagnosis of Pneumocystis carinii pneumonia.

The object of this study was to find a suitable staining method for P. carinii. This parasite is not easily stained and clinical signs are not specific for the diagnosis af P. carinii pneumonia and therefore optimal laboratory methods for observing the organism are extremely valuable. In all, 17 new, conventional and modified staining techniques were used on lung impression smears and tissue sections of Sprague-Dawley rats treated with cortisone (25% cortisone acetate, 1 ml injected twice weekly for 8 weeks). Of these methods modified methylene blue 1 & 2, modified cresyl violet 1, 2, 3, 4, modified Gram, modified Giemsa 2 and modified Griedley techniques have not previously been reported. After comparing readability of the slides, ease of performances, rapidity, availability and sensitivity of these 17 techniques for the diagnosis of P. carinii pneumonia, modified toluidine blue 0 1 & 2, modified methylene blue 1 & 2 and modified cresyl violet 3 & 4 are suggested as the methods of choice for the rapid diagnosis of P. carinii pneumonia.

Animals↗
PubMedDate not supplied

Potential adverse health effects of genetically modified crops.

Genetically modified crops have the potential to eliminate hunger and starvation in millions of people, especially in developing countries because the genetic modification can produce large amounts of foods that are more nutritious. Large quantities are produced because genetically modified crops are more resistant to pests and drought. They also contain greater amounts of nutrients, such as proteins and vitamins. However, there are concerns about the safety of genetically modified crops. The concerns are that they may contain allergenic substances due to introduction of new genes into crops. Another concern is that genetic engineering often involves the use of antibiotic-resistance genes as "selectable markers" and this could lead to production of antibiotic-resistant bacterial strains that are resistant to available antibiotics. This would create a serious public health problem. The genetically modified crops might contain other toxic substances (such as enhanced amounts of heavy metals) and the crops might not be "substantially equivalent" in genome, proteome, and metabolome compared with unmodified crops. Another concern is that genetically modified crops may be less nutritious; for example, they might contain lower amounts of phytoestrogens, which protect against heart disease and cancer. The review of available literature indicates that the genetically modified crops available in the market that are intended for human consumption are generally safe; their consumption is not associated with serious health problems. However, because of potential for exposure of a large segment of human population to genetically modified foods, more research is needed to ensure that the genetically modified foods are safe for human consumption.

Drug Resistance↗