Comparison of endoscopy, radiology and scintigraphy with Tc-99m-exametazine labeled leukocytes and In-111 labeled human polyclonal immunoglobulin G in the diagnosis of inflammatory bowel disease

BACKGROUND: To assess the prognostic value of dipyridamole stress echocardiography in survivors of a first uncomplicated acute myocardial infarction. PATIENTS AND METHODS: A total of 75 patients (68 men, 7 women) aged 58 years (range, 37-77) were studied 3-5 days after a first acute myocardial infarction and followed up for a mean of 10 months. Dipyridamole infusion was administered at high doses: 0.56 mg/kg, adding 0.28 mg/kg if the test was still negative. Two-dimensional echocardiography was continuously recorded during infusion and the test was considered positive if a decrease in regional contractile function appeared and negative if no assynergy was observed up to 15 min after the beginning of dipyridamole administration. A wall motion score index of regional function was derived by summation of individual segment scores divided by the number of interpreted segments. This was calculated for rest and peak dipyridamole echocardiograms. Fifty of 75 patients underwent coronary angiography based on clinical criteria. RESULTS: There were 31 coronary events: 4 deaths, one reinfarction, 13 angina. Thirteen patients underwent coronary revascularization (9 bypass and 4 angioplasty). Dipyridamole echocardiography was positive in 29 patients (39%) and negative in 46 patients (61%). Twenty patients (69%) presented coronary events in the group of positive test versus only 11 (24%) of negatives (p = 0.0001). Four patients died in the positive group while none in the negative group. Sensitivity, specificity and accuracy for all cardiac events were 65, 80 and 73%, respectively. Significant variables from univariate analysis were dipyridamole stress echocardiography response, wall motion score index at peak dipyridamole, ischemic changes in ECG and treatment with two or more antianginal drugs. Multivariate analysis showed positive dipyridamole echocardiography as the only independent prognostic factor to predict cardiac events in postmyocardial infarction patients (RR = 2.56; 95% CI = 1.12-5.84). Four of 19 patients with one vessel disease and 17 of 22 patients with 2-3 vessel disease presented a positive dipyridamole test; whereas the test was negative in the remaining nine patients with normal coronary angiography. CONCLUSION: Dipyridamole stress echocardiography is a safe and feasible pharmacologic stress imaging method to stratify postmyocardial infarction patients at risk of cardiovascular events.     

111In octreotide scintigraphy in the evaluation of head and neck lesions

PURPOSE: To evaluate indium 111 octreotide scintigraphy for the detection of suspected neuroendocrine lesions of the head and neck. METHODS: After receiving 6 mCi of 111In octreotide, 22 patients with suspected lesions of the head and neck were examined with both planar and single-photon emission CT (SPECT). Static images, obtained at 4 hours, included the head/neck, chest, abdomen, and pelvis. Additional SPECT images were obtained at 4 or 24 hours. Studies were compared with available conventional radiologic examinations (12 CT, 11 MR, and three angiographic studies) as well as with clinical and pathologic findings. RESULTS: Eighteen of the 22 patients had abnormal findings at scintigraphy. Eleven paragangliomas were seen in 10 patients, metastatic medullary thyroid carcinoma in three patients, thyroid adenoma in two patients, and Merkel cell tumor, carcinoid, and plasmacytoma in one patient each. Surgical confirmation was available in 13 patients. The smallest lesion detected was 1.5 cm. There was one false-positive and one false-negative examination. CONCLUSION: 111In octreotide scintigraphy is a useful imaging tool for the detection of primary and metastatic neuroendocrine tumors of the head and neck that are larger than 1.5 cm. This technique enables distinction of glomus tumors from other masses (such as neuromas) and can be used in the postoperative setting to distinguish scar from recurrent paraganglioma. Since it is an examination of the entire body, it has great utility for detecting multicentric paraganglioma and for screening patients with familial paraganglioma.     

Relative distribution of plasma cells expressing immunoglobulin G subclass mRNA in human dental periapical lesions using in situ hybridization

Mutation of the BRCA1 gene in well-defined breast cancer families has been associated with an 87% lifetime risk for breast cancer and a 44% risk for ovarian cancer. Recent data indicate that the risk associated with these mutations is considerably lower, although still far greater than the risk for disease in the rest of the population. Approximately 81% of the mutations that have been identified have been frameshift (71%) or nonsense (10%) mutations, and either may result in a truncated protein. The protein truncation test (PTT) is often used to screen patients at high risk, because sequencing of this large (100 kb) gene with its 22 coding exons is an arduous task. The PTT was used to analyze genomic DNA and RNA from the peripheral blood of a 31-year-old Filipino woman with a poorly differentiated, stage 2A breast carcinoma and a family history of breast-ovarian cancer. PTT identified the wild-type protein fragment and an additional truncated protein fragment in the patient's sample. Subsequent direct sequencing of the appropriate coding region revealed a point mutation in exon 11 at nucleotide 2178, resulting in a C > T transition that caused a termination (stop codon) in amino acid 687. To our knowledge, this is the first report of mutation of the BRCA1 gene in a Filipino family, and this in-frame stop-codon mutation has not been reported previously.     

Significance of concentrations and ratio of immunoglobulin G and M in the evaluation of anti-Toxoplasma IGM

The Authors have tested the significance of the correlation of the mean total IgM concentration, the IgG: IgM ratio and the presence of specific anti-Toxoplasma gondii IgM, determined with different serological reactions. The piece of research has been carried out on 72 samples of subjects with active toxoplasmic infections.     

Studies on pharmacological activation of human immunoglobulin G by chemical modification and active subfragments. X. Effect of carboxamidemethylated Fc fragment (CM-Fc) from human immunoglobulin G on delayed type hypersensitivity

The anti-allergic activity of the carboxyamidemethylated Fc fragment (CM-Fc) from human serum immunoglobulin G (IgG) was studied using sheep red blood cell-induced delayed type hypersensitivity in mice (SRBC-DTH). CM-Fc suppressed the DTH response when administered 30 min before, or 4 h after the SRBC challenge, but not when administered 8 h or more after the challenge. The Fc fragment showed no activity. CM-Fc administration 30 min before the challenge was unable to suppress the DTH response in the cyclophosphamide (CY)-treated mice. However, adoptive transfer of splenocytes from mice treated with CM-Fc to CY-pretreated mice caused suppression of the SRBC-DTH response. These results suggest that CM-Fc suppressed the DTH response by mediating the function of CY-susceptible cells.     

Bivariate evaluation of laboratory findings: immunoglobulin G and albumin in cerebrospinal fluid (author's transl)

Using radial immunodiffusion, albumin and immunoglobulin G were determined in non-preconcentrated cerebrospinal fluid from 127 controls and from 239 patients. In controls the concentrations of albumin and immunoglobulin G followed normal distribution. The two variables were correlated linearly (r = 0.60). The elliptic bivariate normal range was calculated, and was found to contain 95% of the paired values. As a clinical limit, this range discriminated more effectively between normal and altered pairs than the two one-dimensional normal ranges X+/-2 s, thus improving the evaluation of laboratory findings in the single case. Likewise in clinically defined groups of patients, bivariate evaluation of results provided additional evidence. In many distinct clinical syndromes, e.g. bacterial encephalomeningitis, polyneuropathy, amyotrophic lateral sclerosis, albumin and immunoglobulin G concentrations exhibited an especially close correlation, probably resulting from damage to the blood-cerebrospinal fluid barrier. However, no correlation of these two variables was detected in acute encephalomeningitis due to virus infection, and in multiple sclerosis: in these groups, immunoglobulin G concentrations were elevated independently of albumin. Since evidence is lacking as to the pathogenesis of multiple sclerosis, it seems noteworthy that the same phenomenon was observed in a well-defined group of viral infections.     

Development and comparison of assays for measuring immunospecific antibody response in serum of chickens and rabbits immunized with human immunoglobulin G

The antibody response development during polyclonal antibody production is a relevant parameter to monitor during the immunization period to be able to optimize the immunization protocol and to determine the optimal antibody harvest time. Although rabbits and other mammals are most often used for polyclonal antibody production, the chicken is a relevant alternative. There are both scientific reasons, economic reasons, and animal welfare reasons to consider when choosing the chicken instead of a mammal for this purpose, because antibodies in generous quantities can be harvested from the egg yolk. This study compared different assays for measuring antibody response in rabbit and chicken serum. An inhibition liquid phase absorption assay (ILPAA), a rocket immunoelectrophoresis (RIE) assay, and a line immunoelectrophoresis (LIE) assay were compared to ELISAs. The ELISA proved to be the most useful assay for routine use, as it was less time-consuming and because the assay could easily be adapted to both serum antibody types. However, electrophoretic assays were the most useful as combined analytical and quantitative tools and must be considered essential when analyzing specificities of polyclonal antibody preparations.     

Relationship between ABO blood group and levels of Gal alpha,3Galactose-reactive human immunoglobulin G

BACKGROUND: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine glycoproteins and glycolipids, but is not expressed by human cells. Consequently human sera contain anti-alphaGal natural antibodies. The human blood group B antigen [Gal alpha1,3(Fuc1,2)Galactose] is differentiated from the alphaGal epitope by the presence of a fucosyl group. METHODS: To determine whether the expression of the B antigen has any effect on the level of alphaGal-reactive natural antibodies, equal numbers (n=12) of A, B, AB, and O serum samples were evaluated by ELISA and flow cytometry. RESULTS: A significant reduction in IgG alphaGal reactivity was observed with serum samples from B antigen-expressing donors (B, AB) relative to non-B antigen-expressing donors (A, O). CONCLUSIONS: These results are consistent with the possibility that anti-alphaGal antibodies in non-B antigen-expressing individuals include a subset that is reactive with the structurally related B antigen and that this subset is absent in B and AB individuals.     

Evaluation of the efficacy of human antimeningococcal immunoglobulin G in infant rats experimentally infected with Neisseria meningitidis group B

Infants rats, a well known model for the experimental reproduction of bacterial meningitis, were used by us to test the protective potential of antibodies developed in humans who had been vaccinated with the Cuban antimeningitis vaccine (VA-MENGOCBC). Newborn rats were inoculated by the intraperitoneal and intranasal routes with suspensions of Neisseria meningitidis group B bacteria. Bacteremia kinetics were evaluated from blood and brain-spinal fluid cultures. Samples of the central nervous system were taken and smears of backbone fluids prepared for histopathologic evaluations. Characterization of bacteremia evolution, as well as the mean lethal dose of germs and histopathologic features, were determined. After standardization of the model, therapeutic schemes were applied using passive immunization pre- and post-infection with N. meningitidis. A significant level of protection was obtained in relation to control animals that received the same challenge doses.     

Dimers and trimers of immunoglobulin G covalently cross-linked with a bivalent affinity label

A bivalent affinity label, bis(alpha-bromoacetyl-epsilon-2,4-dinitrophenyllysylproline)ethylenediamine, has been synthesized. Treatment of anti-2,4-dinitrophenyl antibodies with this compound produces a mixture of covalently and noncovalently cross-linked material. Only specific antibodies are covalently cross-linked, suggesting that covalent attachment occurs in the variable regions. Covalently cross-linked dimers and trimers have been isolated from the reaction mixture in a high state of purity, in yields of about 12 and 4%, respectively. The complexes are stable in solutions containing 10(-4) M hapten and can therefore be used as sensitive probes of immune effector functions.     

Analysis of hepatocyte distribution and survival in vascular beds with cells marked by 99mTC or endogenous dipeptidyl peptidase IV activity

The present study was designed to clarify the effects of TJ-8117 on apoptosis in the glomeruli of 5/6 nephrectomized rats. TJ-8117 (400 mg/kg/day), captopril (50 mg/kg/day) and nicardipine (50 mg/kg/day) were administered as drinking water from the 56th day after renal ablation, and continued throughout the experiment. All rats were sacrificed at 13 weeks and renal tissues were removed to quantify histopathological and apoptotic parameters in glomeruli. TJ-8117 inhibited proteinuria, matrix index and decrease in the number of total cells in glomeruli of nephrectomized rats. In addition, the increase in apoptotic body and DNA fragmentation was significantly inhibited in the TJ-8117-treated group. Captopril and nicardipine failed to inhibit both parameters. In 400 mg/kg of the TJ-8117 treated group, the number of Bcl -2 positive cells in the glomeruli was elevated compared with the 5/6 nephrectomized control group. In addition, the number of Bax positive cells in the TJ-8117 group was significantly suppressed in a dose-dependent manner. These results suggest that TJ-8117 may inhibit apoptosis in the late stage of this model by suppressing matrix accumulation and progression of glomerulosclerosis. The apoptosis-preventing effect may be mediated by decreased expression of Bax in the glomerular cells.     

Aggregation of the human high affinity immunoglobulin G receptor (FcgammaRI) activates both tyrosine kinase and G protein-coupled phosphoinositide 3-kinase isoforms

Phosphoinositide 3-kinases (PI3-kinases) play an important role in the generation of lipid second messengers and the transduction of a myriad of biological responses. Distinct isoforms have been shown to be exclusively activated either by tyrosine kinase-coupled or G protein-coupled receptors. We show here, however, that certain nonclassical receptors can couple to both tyrosine kinase- and G protein-dependent isoforms of PI3-kinase: thus, aggregation of FcgammaRI, the human high affinity IgG receptor, on monocytes unusually leads to activation of both of these types of PI3-kinase. After aggregation of FcgammaRI, phosphatidylinositol 3,4, 5-triphosphate (PIP3) levels rise rapidly in interferon gamma-primed cells, reaching a peak within 30 sec. Moreover, and in contrast to the situation observed after stimulation of these cells with either insulin or ATP, which exclusively activate the tyrosine kinase- and G protein-coupled forms of PI3-kinase, respectively, PIP3 levels remain elevated up to 15 min after receptor aggregation. We show here that although the initial peak results from transient activation of the p85-dependent p110 isoform of PI-3kinase, presumably through recruitment of tyrosine kinases by the gamma chain, the later sustained rise of PIP3 results from activation of the G protein betagamma subunit-sensitive isoform, p110gamma. This finding indicates that receptors lacking an intrinsic signaling motif, such as FcgammaRI, can recruit both tyrosine kinase and G protein-coupled intracellular signaling molecules and thereby initiate cellular responses.     

Electrophoretic studies of the cystic fibrosis ciliary inhibitor and its interaction with immunoglobulin G

The cystic fibrosis ciliary inhibitor (CFCI) has been partially purified from serum and plasma of cystic fibrosis (CF) homozygotes and heterozygotes, and from media of cultured fibroblasts derived from cystic fibrosis genotypes. Characterization and comparison of fractions containing the CFCI were carried out by polyacrylamide gel electrophoresis. Gel electrophoresis confirmed previous molecular weight estimations of 4,500 to 11,000 for the CFCI and provided an estimate of the number of proteins present in the fractions. Low molecular weight proteins from serum and media were combined with IgG preparations. No specific binding to IgG by the media fraction containing the CFCI could be demonstrated by the techniques employed. There was decreased binding of the low molecular weight serum fraction containing CFCI to native IgG molecules from cystic fibrosis patients as compared to IgG from normal individuals. However, IgG from CF individuals demonstrated increased binding of the cfci-containing low molecular weight serum fraction after gel filtration in the presence of guanidinium chloride. This suggests: 1) that very low concentrations of CFCI are present in media fractions; and 2) that native CF IgG cannot bind the low molecular weight CFCI fractions to the same degree as native IgG from normals or CF IgG that has been dissociated from non-covalently bound components.     

Clinical evaluation of hepatic blood flow and liver function with 99mTc-DTPA-HSA

Clinical evaluation of hepatic blood flow and liver function of 30 patients with 99mTc-human serum albumin scintigraphy (99mTc-HSA) was done. In this study we evaluated the ratio of portal venous to total hepatic blood flow as the hepatic perfusion index (HPI), and 99mTc-HSA uptake ratio of the liver to the heart at 2 hrs after bolus injection as the hepatic uptake score (HUS). In clinical study, we estimated both HPI and HUS in patients with liver cirrhosis (LC) and non-liver-cirrhosis (non-LC), and in the same way estimated these two factors in the patients before and after distal splenorenal shunt operations (DSRS). We also estimated the correlation of both HPI and HUS with other liver functions. Finally we made 3 dimensional liver imagings using 99mTc-HSA. The mean HPI was 0.42 +/- 0.24 in the LC group and 0.66 +/- 0.19 in the non-LC group (p < 0.02). The mean HUS was 0.50 +/- 0.17 in the LC group and 0.67 +/- 0.13 in the non-LC group (p < 0.02). The mean HPI decreased to 32-54% after the DSRS operation, but there was no such change with HUS. Correlation between HPI and KICG was significant (r = 0.51, p < 0.02), and there was also a correlation between HUS and PT, HPT (p < 0.02), and ICGR15 (p < 0.02). We concluded that HPI and HUS were both useful factors in estimating hepatic blood flow and liver function.     

Kinetics of specific immunoglobulin A, M and G production in the duodenal and caecal mucosa of chickens infected with Eimeria acervulina or Eimeria tenella

The development and appearance of antibody was studied in the intestine and serum from histocompatible GB1 chickens orally infected with oocysts of Eimeria acervulina (restricted to the duodenum) or Eimeria tenella (restricted to the caeca). The local immune response was measured as the specific antibody levels in the supernatants of intestinal fragments (duodenum and caecum) maintained in culture for 16 h at 41 degrees C, 5% CO2, 95% air. Specific IgM was detected 1 week after E. acervulina infection, and the specific IgA and IgG contents of the duodenum and caecum were significantly elevated (P < 0.001) after 2 weeks. The intestinal specific IgG content was raised. E. tenella infection resulted in specific IgA only in the parasitized area during the second week post-infection (P < 0.05). Specific IgM and IgG were both detected in the duodenum and caecum, respectively, 1 and 2 weeks p.i. Production of parasite-specific immunoglobulins was always significantly higher in the parasitized than in the unparasitized areas (caeca for E. acervulina, duodenum for E. tenella). This ex vivo culture assay of intestinal fragments used to measure the mucosal immune response of intestinal areas showed a significant production of specific IgA and IgM. In addition, high levels of IgG were also measured. The role of this specific IgG in Eimeria infection remains to be determined.     

G2 repair and evaluation of the cytogenetic damage induced by low doses of X-irradiation during G0 in human lymphocytes

In the present study two cytogenetic parameters were used to evaluate the DNA damage induced by low doses (1 up to 40 rad) of X-ray irradiation in G0 human lymphocytes. These parameters were the frequency of chromosomal lesions in G2 and the length of this cell cycle phase. The frequency of chromosomal lesions in G2 was determined by scoring the number of chromosomal aberrations in G0 irradiated lymphocytes post treated with two inhibitors of G2 repair mechanisms: caffeine and 3-aminobenzamide. A dose-dependent increase in chromosomal aberrations yield was detected in G0 lymphocytes X-ray irradiated with or without post treatment with these two DNA repair inhibitors during G2. Nevertheless, the dose response in this latter condition was higher than the one detected in control cells, indicating that the increase of irradiation dose in G0 lymphocytes produces an increment in the number of DNA lesions arriving to be repaired in G2. The analysis of the dose-response relationships for G2 length showed an statistically significant X-ray dose-dependent increase (G2 delay) from 2.5 up to 40 rad and a positive correlation between G2 delay and the frequency of chromosomal lesions in G2. These results suggest that the DNA lesions induced by low doses of X-irradiation in G0 lymphocytes may be higher than that detected by the standard method (control conditions) and may be responsible for an increase in G2 length. We propose, therefore, that an analysis of these two cytogenetic parameters can improve the evaluation of the DNA damage induced by low doses of X-rays irradiation in G0 cells.