Biomedical subjects

M R Price

Publications and source records attributed to M R Price.

At least 55 records · Page 3Linked to original sources

PubMed1998

Summary report on the ISOBM TD-4 Workshop: analysis of 56 monoclonal antibodies against the MUC1 mucin. San Diego, Calif., November 17-23, 1996.

Sixteen research groups participated in the ISOBM TD-4 Workshop in which the reactivity and specificity of 56 monoclonal antibodies against the MUC1 mucin was investigated using a diverse panel of target antigens and MUC1 mucin-related synthetic peptides and glycopeptides. The majority of antibodies (34/56) defined epitopes located within the 20-amino acid tandem repeat sequence of the MUC1 mucin protein core. Of the remaining 22 antibodies, there was evidence for the involvement of carbohydrate residues in the epitopes for 16 antibodies. There was no obvious relationship between the type of immunogen and the specificity of each antibody. Synthetic peptides and glycopeptides were analyzed for their reactivity with each antibody either by assay of direct binding (e.g. by ELISA or BiaCore) or by determining the capacity of synthetic ligands to inhibit antibody binding interactions. There was good concordance between the research groups in identifying antibodies reactive with peptide epitopes within the MUC1 protein core. Epitope mapping tests were performed using the Pepscan analysis for antibody reactivity against overlapping synthetic peptides, and results were largely consistent between research groups. The dominant feature of epitopes within the MUC1 protein core was the presence, in full or part, of the hydrophilic sequence of PDTRAPAP. Carbohydrate epitopes were less easily characterized and the most useful reagents in this respect were defined oligosaccharides, rather than purified mucin preparations enriched in particular carbohydrate moieties. It was evident that carbohydrate residues were involved in many epitopes, by regulating epitope accessibility or masking determinants, or by stabilizing preferred conformations of peptide epitopes within the MUC1 protein core. Overall, the studies, highlight concordance between groups rather than exposing inconsistencies which gives added confidence to the results of analyses of the specificity of antimucin monoclonal antibodies.

Amino Acid Sequence↗

PubMed1998

Epitope mapping of anti-MUC1 mucin protein core monoclonal antibodies.

A panel of 56 murine monoclonal antibodies against the MUC1 mucin was analysed for reactivity against purified MUC1 mucin and synthetic MUC1 mucin protein core-related peptides. In an ELISA assay, with purified normal urinary mucin as the target antigen, 48/56 (86%) of antibodies showed positive reactivity. A smaller proportion of antibodies, 31/56 (55%), reacted with a bovine serum albumin conjugate containing the synthetic peptide, APDTRPAPG. This peptide represents the hydrophilic region of the tandem repeat sequence of the MUC1 mucin core. These 31 anti-mucin core antibodies were then evaluated for reactivity with a set of overlapping heptamers with sequences based upon that of the 20-amino acid tandem repeat of the MUC1 protein core. For this purpose, the 'Pepscan' procedure was employed to detect antibody binding to peptides tethered at their carboxy termini to the polypropylene pins. Synthetic peptides binding to these antibodies were identified for 29 of the samples provided and epitopes or 'minimum binding units' were deduced for these. Most antibodies bound to epitopes of 4 amino acid residues with the sequence RPAP occurring most frequently. The results confirm that the short hydrophilic region PDTRPAP in the MUC1 mucin core is immunodominant in the induction of antibodies to the MUC1 mucin since half of the antibodies submitted reacted with this peptide.

Amino Acid Sequence↗

PubMed1997

Purification of monoclonal antibodies by epitope and mimotope affinity chromatography.

Murine monoclonal antibodies raised against the carcinoma-associated MUC1 mucin have applications in the diagnosis and therapy of human cancer. Many of these antibodies define linear epitopes of three, four or five amino acids within an immunodominant region of the MUC1 protein core. Various synthetic peptides which incorporated this region were prepared and covalently linked to agarose beads for use as affinity matrices. An unrelated peptide was identified as a mimotope for one of the anti-MUC1 antibodies using phage display technologies and this was also evaluated as a potential ligand in an affinity matrix. Epitope affinity chromatographic purification of an anti-MUC1 antibody was performed using hybridoma tissue culture supernatants as sample. Following sample application and column washing, antibody was desorbed from the matrix by gradient elution with increasing concentrations of NaSCN. The procedure has proved efficient for the purification of anti-MUC1 antibodies and the concentration of NaSCN required for antibody desorption gives a measure of the relative binding affinity of the antibody for the peptide epitope matrix so that separation strategies may be optimised.

Amino Acid Sequence↗

PubMed1997

Preclinical evaluation of copper-67 labelled anti-MUC1 mucin antibody C595 for therapeutic use in bladder cancer.

Transitional cell carcinoma of the bladder is the fifth commonest cause of death from cancer in men in the United Kingdom. Most patients present early with superficial disease, though with current treatment up to 20% progress to invasive disease, which has a poor prognosis. Better local treatments are required to limit this tumour progression. The ease of access to the bladder via a catheter provides the ideal opportunity for antibody (Ab) targeted therapy. We have previously shown that indium-111 labelled anti-MUC1 mucin Ab C595 selectively localises to bladder tumours after intravesical administration. We have selected copper-67 as an alternative radiolabel with suitable physical characteristics for radioimmunotherapy. This communication demonstrates that C595 can be reproducibly labelled with 67Cu and that the radioimmunoconjugate is both stable and maintains high immunoreactivity. Pilot studies on cystectomy specimens in a novel ex vivo system and in one patient confirmed the ability of this conjugate to localise to tumour after intravesical administration. On the basis of these studies we are now in a position to study the intravesical administration of 67Cu-labelled C595 in patients with bladder cancer with a view to a therapeutic trial.

Administration, Intravesical↗

PubMed1997

Modified Nissen fundoplication for reduction of fundoplication failure.

Failure of the Nissen fundoplication can be secondary to disruption of the wrap or slippage of the stomach upward within the wrap. A modification of the Nissen fundoplication was devised and implemented between 1982 and 1995 to eliminate these complications. This report describes the modification and the results. Commonly, the Nissen fundoplication uses a single anterior row of sutures securing the wrapped stomach to the esophagus. This modification reinforces the wrap with two additional rows of suture, one right lateral and one left lateral, each further anchoring the wrapped stomach to the esophagus. This retrospective analysis compares the Nissen and modified Nissen fundoplications performed at our institution. Fundoplication operations were considered a failure if they required a reoperation secondary to wrap disruption or stomach slippage. Data were analyzed using the chi 2 method. A total of 948 fundoplication procedures were performed; 326 Nissen and 622 modified Nissen. Follow-up ranged from 0.5 to 13 years (mean, 6 years). Thirteen wrap disruptions and six stomach slippages occurred in the Nissen group (5.8%); 10 wrap failures and no stomach slippages occurred in the modified Nissen group (1.6%), P < .05. The authors conclude that this modification of the Nissen fundoplication significantly reduces wrap disruptions and stomach slippages.

Chi-Square Distribution↗

PubMed1997

Ileal atresia with total colonic aganglionosis.

This is the 17th report of the case of an infant who had ileal atresia associated with Hirschsprung's disease, and the second with ganglion cells distal to the atresia. Experience suggests that Hirschsprung's disease should be suspected in all forms of bowel atresia.

Hirschsprung Disease↗

PubMed1997

Production and characterization of a recombinant anti-MUC1 scFv reactive with human carcinomas.

Recombinant single-chain fragments (scFv) of the murine anti-MUC1 monoclonal antibody C595 have been produced using the original hybridoma cells as a source of variable heavy (V(H))- and variable light (V(L))-chain-encoding antibody genes. The use of the polymerase chain reaction (PCR), bacteriophage (phage) display technology and gene expression systems in E. coli has led to the production of soluble C595 scFv. The scFv has been purified from the bacterial supernatant by peptide epitope affinity chromatography, leading to the recovery of immunoreactive C595 scFv, which was similar in activity to the C595 parent antibody. Analysis by DNA sequencing, SDS-PAGE and Western blotting has demonstrated the integrity of the scFv, while ELISA, FACScan analysis, fluorescence quenching, quantitative immunoreactivity experiments and immunohistochemistry confirm that the activity of the scFv compares favourably with that of the parent antibody. The retention of binding activity to MUC1 antigen on human bladder and breast carcinoma tissue specimens illustrates the potential application of this novel product as an immunodiagnostic and immunotherapeutic reagent.

Amino Acid Sequence↗

PubMed1997

Computerized education in a multi hospital university medical center.

The advantages of using authoring, instructional, and informational computer applications in a university-based multi-hospital medical teaching center are vast. Software applications are used by the staff development educators at The Presbyterian Hospital, Columbia University Medical Center (CPMC) for test construction and administration, information processing, instruction, assessment, and evaluation. The media formats include Windows and DOS based CAI programs, CD ROM, IVD, INTERNET sites, and other on-line resources. This presentation will focus on how nurse educators use the various types of software applications available on the CPMC network and in the multimedia center, and on the benefits experienced by learners, educators, and nursing management and administration.

Academic Medical Centers↗

PubMed1996

Respiratory mucins: identification of core proteins and glycoforms.

At least eight mucin apoproteins are expressed by the tracheobronchial epithelium, but it is not known which, if any, of these are major constituents of the respiratory secretions responsible for the formation of the mucus gel. To address this we have isolated mucins from normal, asthmatic and chronic bronchitic secretions. The asthmatic mucin reduced subunits were fractionated into four populations (I-IV) by anion-exchange HPLC. Amino acid and monosaccharide compositional analysis, as well as M(r) and size measurements, indicate that two of these populations (I and II) are glycoforms of the same or related apoprotein(s) and that the other populations contain two different apoproteins. A panel of antibodies and antisera recognizing the variable number tandem repeat (VNTR) of specific mucin apoproteins did not, as predicted, react with the glycosylated molecules, but after deglycosylation the majority of these probes (with the exception of those to MUC2, which were negative) reacted at a low level with each of the subunit populations. In contrast, an antiserum against a non-VNTR sequence of MUC5AC identified one of the populations (III) as the MUC5AC mucin. The MUC5AC reduced subunit had an M(r) of 2.2 x 10(6) and an RG (radius of gyration) of 57 nm. The genetic identities of the major mucin (populations I and II) and a minor component (population IV) were not established. The MUC5AC mucin was also identified as a major component in the pooled normal secretions from 20 individuals, whereas in a chronic bronchitic sample it was only a minor constituent. Furthermore, in all these different respiratory secretions the MUC5AC mucin appears as a similar biochemical entity, as assessed by Mono Q chromatography and agarose electrophoresis, suggesting that it may have a well-defined pattern of glycosylation in the respiratory tract.

Amino Acid Sequence↗

PubMed1996

Effect of glycosylation of a synthetic MUC1 mucin-core-related peptide on recognition by anti-mucin antibodies.

Human epithelial mucins are heterogeneously glycosylated proteins associated with breast and ovarian cancer. Several peptide-reactive anti-mucin MUC1 monoclonal antibodies are used in experimental and diagnostic assays but it is not known how glycosylation of the mucin influences antibody recognition. In this report we show that increasing glycosylation of a synthetic 25-amino acid fragment of the MUC1 core protein with N-acetylgalactosamine (GalNAc) elicits different responses in its recognition by two anti-MUC1 antibodies, C595 and HMFG1. We propose that increasing glycosylation of the synthetic mucin fragment produces an alteration in the structure of the epitope which enhances binding in C595, but not in HMFG1.

Acetylgalactosamine↗

PubMed1996

Long-term results with the Kasai operation for biliary atresia.

OBJECTIVE: To evaluate long-term outcome in a series of children with biliary results atresia treated by portoenterostomy. DESIGN: Case series of consecutive infants with biliary atresia with 10-year follow-up. Data were obtained by retrospective chart review or phone interview. SETTING: A tertiary academic medical center and regional children's hospital. PATIENTS: A consecutive series of 104 infants diagnosed with biliary atresia more than 10 years ago were evaluated. Eighty-nine had totally obliterated extrahepatic ducts, 4 had proximal hilar cysts (correctable type), and 11 had patency of the gallbladder and distal common duct. INTERVENTIONS: Ninety-eight patients underwent biliary reconstruction and 6 had exploration only. Seventy-four infants underwent reconstruction using a Rouxen-Y with exteriorization. The 11 infants with distal patency underwent a portocholecystostomy ("gallbladder Kasai"). The remainder had various modifications of the Kasai operation. MAIN OUTCOME MEASURES: Survival, liver function, complications, growth, and development. RESULTS: The 6 patients who did not have a portoenterostomy died. Of the 98 who had a reconstruction, 63 died (mean age at death, 27 months; median, 13.4 months), 10 following liver transplantation. Twelve of the 35 survivors ultimately required liver transplants. Twenty-three children are alive more than 10 years after portoenterostomy without the need for transplantation. Two thirds have experienced some manifestation of portal hypertension (ie, variceal bleeding, hypersplenism, ascites). Nineteen patients (79%) are anicteric with normal liver synthetic function and are in an age-appropriate school grade or working and living independently. CONCLUSIONS: We found that surgical correction of biliary atresia offers long-term survival for about one quarter of patients, provides palliation until liver transplantation becomes necessary, and if surgical correction is not feasible, biliary atresia is uniformly fatal. The outlook is good for those children who survived more than 10 years and justifies continued attempts to establish bile flow in infants with biliary atresia.

Adolescent↗

PubMed1996

A CD66a-specific, activation-dependent epitope detected by recombinant human single chain fragments (scFvs) on CHO transfectants and activated granulocytes.

Antibodies to CD66 recognize at least five members (CD66a-e) of the carcinoembryonic antigen (CEA) family. Recombinant human single-chain Fv fragments (scFvs) that bind specifically to CD66a (biliary glycoprotein) were obtained from a naive human scFv library. The scFvs bound to the N-domain of CD66a on Chinese hamster ovary (CHO) transfectants but did not bind to freshly isolated peripheral granulocytes or to dimethylsulfoxide-treated HL-60 cells. In contrast, scFvs bound well to granulocytes that were short-term activated with N-formyl-Met-Leu-Phe or phorbol 12-myristate 13-acetate and to human HL-60 cells that were treated with all-trans-retinoic acid to induce granulocytic differentiation. Quantification of antigenic sites showed that the activation-dependent CD66a epitopes were expressed on nearly all of the CD66a molecules on CHO-biliary glycoprotein transfectants, but they were detected only on a portion of the molecules on activated polymorphonuclear neutrophils and differentiated HL-60 cells. Binding of CD66a scFvs to their neoepitopes on prestimulated PMNs induced respiratory burst, suggesting that CD66a is capable of delivering transmembrane signals in these cells.

Animals↗

PubMed1996

Recurrent appendicitis after initial conservative management of appendiceal abscess.

Therapy for children with appendiceal abscess remains controversial. The authors present two such cases initially treated conservatively, without interval appendectomy, that later had recurrent appendicitis. An 8-year-old boy presented with fever, abdominal pain, and a right-lower-quadrant abscess (noted by ultrasonography). During laparotomy, the abscess was drained and the appendix was not found. He was lost to follow-up but returned 2 1/2 years later with perforated appendicitis. An appendectomy was performed, and image-guided drainage of a postoperative abscess was required. A 10-year-old girl presented with fever and right-lower-quadrant pain. Computed tomography showed a multiloculated mass. During laparotomy, the cecum was found to be densely adherent to the pelvic organs and bowel, so the surrounding abscess was drained. Interval appendectomy was refused. The patient returned 8 months later with recurrent acute appendicitis and an appendiceal abscess requiring appendectomy and drainage. Although initial drainage alone of appendiceal abscess is efficacious, the authors strongly advocate interval appendectomy as a critical component of the complete management of this entity.

Abscess↗

PubMed1996

Management of esophageal varices in children by endoscopic variceal ligation.

Endoscopic variceal sclerotherapy (EVS) has been considered the mainstay of therapy for bleeding esophageal varices in adults. However, recent data have shown that endoscopic variceal ligation (EVL) is just as efficacious and has fewer complications than EVS. Although there are many reports concerning EVL in adults, only a few studies have been done in children. This report describes experience with EVL in 22 children with esophageal variceal hemorrhage. Eighty-seven EVL procedures were performed during a 9-year period in 22 children. The causes of portal hypertension were biliary atresia (10), portal vein thrombosis (8), chronic active hepatitis (1), cirrhosis secondary to cystic fibrosis (2), and primary sclerosing cholangitis (1). The age range at the onset of variceal bleeding was 8 months to 19 years. Twelve patients had EVS before EVL treatment was begun. Distal esophageal varices (one to four per session) were mechanically ligated using an elastic band ligature device attached to a flexible endoscope. The aim of therapy was obliteration of distal esophageal varices by EVL, every 2 to 4 weeks, until eradication. Subsequent EVL was dictated by the status of the varices. Outcome was assessed with respect to survival, rebleeding, status of varices, and complications. The patients underwent a mean of four sessions of EVL (range, one to eight). Four patients subsequently underwent liver transplantation. Of the 18 patients remaining (average follow-up period, 5.3 years), 12 had their varices eradicated (average of four EVL sessions), four are still in treatment, one has not been evaluated in the past 4 years, and one died of liver failure. Complications included bleeding between sessions (6 patients), cervical esophageal perforation (1 patient), and transient fever (2 patients). No child has experienced symptoms of esophageal stenosis or gastroesophageal reflux. Two patients died of liver disease, unrelated to bleeding from portal hypertension. EVL is effective in controlling variceal hemorrhage in children with portal hypertension, regardless of etiology. The complication rate is low, and EVL is an acceptable and perhaps preferable alternative to EVS in children with esophageal varices.

Adolescent↗

PubMed1996

Expression of a peptide epitope of the colonic mucin MUC2 in precursor lesions to gastric carcinoma.

Previous histochemical studies have shown that changes occur in the composition of mucins both in preneoplastic and neoplastic lesions of the gastric mucosa. Since monoclonal antibodies are now available which recognize the protein product of distinct mucin genes, they are likely to provide useful tools for evaluating these changes. Thus, a monoclonal antibody 996/1 raised against a peptide epitope of the colonic mucin MUC2 was examined for its potential as a prognostic indicator in gastric cancer. 996/1 works well on formalin-fixed paraffin sections and shows good staining of the colonic goblet cells in the region of the golgi, while there is no staining of normal control gastric mucosa. The epitope was detected in all cases of intestinal metaplasia (44 samples) and some but not all cases of dysplasia (26 samples) and gastric carcinoma (74 samples). There was no significant difference between the positivity of the tumours according to their classification, stage and lymph node status. These results unfortunately gave little indication that this antibody would be a useful prognostic tool in gastric cancer. However, the pattern of 996/1 staining provides useful information about the molecular changes in mucin expression that occur in gastric carcinogenesis.

Antibodies, Monoclonal↗

PubMed1995

Expression of monoclonal-antibody-defined antigens in fractions isolated from human breast carcinomas and patients' serum.

The aim of this study was to examine tissue from patients with breast carcinoma or benign breast disease for the presence of monoclonal-antibody-defined antigens, including the MUC1 mucin and carcinoembryonic antigen CEA. The tests were performed by sodium dodecyl sulphate/polyacrylamide gel electrophoretic separation of proteins, electrophoretic transfer to nitrocellulose membranes and immunostaining with the monoclonal antibodies. Some of the antigens identified are known to circulate at high levels in some but not necessarily all, breast carcinoma patients. Serum from a panel of ten breast cancer patients was subjected to a fractionation procedure designed to release antigen from immune complexes, and again these samples were analysed for the presence of monoclonal-antibody-defined antigens. A high frequency of positive reactions was detected by the anti-MUC1 monoclonal antibody C595 with both breast carcinoma subcellular membrane fractions as well as antigen fractions eluted from circulating immune complexes. No reactions were observed with equivalent materials from benign breast disease samples. The findings illustrate the variability in antigen expression between breast tumours. The data also indicate that a proportion of patients respond to their tumour by the production of antibodies that recognise the MUC1 antigen in their circulation.

Antibodies, Monoclonal↗

PubMed1995

Primary sequence determination and molecular modelling of the variable region of an antiMUC1 mucin monoclonal antibody.

Polymerase chain reaction (PCR) products representative of the DNA sequence coding for the variable heavy (VH) and the variable light (VL) chains of an antiMUC1 mucin monoclonal antibody, C595, have been produced. These products were cloned, sequenced, and the primary amino acid sequences of the VH and VL regions deduced. The hypervariable complementarity determining regions (CDRs) and framework regions in the heavy and light chains were located, and homologies with canonical forms for the CDR loops L1, L2, L3, H1 and H2 were identified by database searching. The structure for the H3 loop was calculated directly. Computational molecular modelling was accomplished using the fully automated AbM package (Oxford Molecular, Oxford, U.K.). Energy minimisation was performed using the program InsightII (Biosym, San Diego, California, U.S.A.). The investigation provides a basis for the molecular analysis of the antigen binding site of the C595 antibody with the aim to identify key residues and interactions involved in the immune recognition of the C595 antibody defined epitope, which is expressed in the majority of breast and ovarian carcinomas.

Amino Acid Sequence↗

PubMed1995

Pre-treatment serum levels of tumour markers in metastatic breast cancer: a prospective assessment of their role in predicting response to therapy and survival.

The value of pre-treatment serum tumour marker levels in 85 consecutive patients of newly diagnosed metastatic breast cancer was prospectively assessed for predicting response to therapy and survival. The markers studied were carcinoembryonic antigen (CEA), orosomucoid (ORO), erythrocyte sedimentation rate (ESR), C reactive protein (CRP), ferritin (FERR), human milk fat globule membrane 1 and 2 (HMFG1 and 2), CA 15-3 and NCRC-11. There was no correlation between serum marker levels and response to therapy. Only serum concentrations of CRP (P = 0.02), FERR (P = 0.001), HMFG1 (P = 0.004) and HMFG2 (P = 0.04) were predictive for survival. The prognostic significance of HMFG1 was restricted to a minority of patients (7%) with extreme values of these serum markers.

Aged↗