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Biomedical subjects

R J Thompson

Publications and source records attributed to R J Thompson.

At least 127 records · Page 7Linked to original sources

Cefonicid vs. cefoxitin for cesarean section prophylaxis.

A randomized, prospective study compared a long-acting, second-generation cephalosporin, cefonicid (Monocid), with a short-acting, second-generation cephalosporin, cefoxitin (Mefoxin), for cesarean section prophylaxis. One hundred thirty-nine patients were enrolled, with 81 receiving a 1-g intravenous dose of cefonicid after cord clamping and 58 receiving a 2-g dose of intravenous cefoxitin after cord clamping and at 6, 12 and 18 hours postpartum. In those patients receiving cefonicid prophylaxis, endometritis incidence was 17.3% (14 of 81). This finding was not statistically significant (P less than .397) when compared to the 12.1% incidence of endometritis (7 of 58) with cefoxitin. In addition, the febrile morbidity incidence for cefonicid prophylaxis was 23.5% (19 of 81) as compared to 15.5% (9 of 58) for cefoxitin (P less than .25). Because the two drugs appear to be equally efficacious, cefonicid may be the better choice because of its markedly lower cost.

Adult↗

Detection of cerebral injury after total circulatory arrest and profound hypothermia by estimation of specific creatine kinase isoenzyme levels using monoclonal antibody techniques.

New 2-site labeled monoclonal antibody techniques were used to measure serially plasma levels of brain-type creatine kinase (CK-BB), heart-type creatine kinase (CK-MB) and muscle-type creatine kinase (CK-MM) during a 20-hour postoperative period in 24 infants after deep hypothermia and total circulatory arrest used in pediatric cardiac surgery. A control group of 7 children undergoing cardiovascular procedures without extracorporeal circulation or circulatory arrest also were studied. There were marked increases in CK-MB and CK-BB levels in the circulatory arrest group but not in the closed group. CK-BB increased from 3.2 +/- 0.5 to 27 +/- 10 ng/ml and CK-MB from 5.9 +/- 2.1 to 137 +/- 12 ng/ml. The CK-MM concentrations increased from 299 +/- 91 and 194 +/- 49 ng/ml to 1,220 +/- 274 and 1,322 +/- 142 ng/ml in the closed and circulatory arrest groups, respectively. Peak levels of CK-MB and CK-BB occurred an average of 133 and 127 minutes, respectively, after reperfusion. The half-time of CK-BB differed significantly from that of CK-MB (149 +/- 15 vs 359 +/- 20 minutes). The arrest time had a more marked effect on CK-BB concentration than on CK-MB and CK-MM concentrations. Arteriointernal jugular venous concentration differences were consistently negative for CK-BB in the circulatory arrest group, but not for CK-MM and CK-MB.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

Serial measurement of arterial and internal jugular venous creatine kinase isoenzyme BB (CK-BB) after deep hypothermic total circulatory arrest in pediatric cardiac surgery.

Profound hypothermia and circulatory arrest in infants and children undergoing cardiac surgery were followed by abnormally high plasma levels of creatine kinase isoenzyme BB (CK-BB). Differences in the levels of enzymes in the femoral arterial and jugular venous blood indicated that the origin of the additional enzyme was the brain. The extent of the rise in enzyme levels was related to the duration of circulatory arrest. These data suggest that measurements of the CK-BB enzyme in plasma provide quantitative information about cerebral damage during cardiac surgery.

Brain↗

Mental retardation: a controversial indication for hysterectomy.

Some mentally retarded women, particularly those severely affected, may benefit from hysterectomy. Although the contraceptive effect of hysterectomy frequently may be useful, this procedure should be performed only in those women for whom menstrual hygeine is (or is anticipated to be) a major problem. A recommendation from a pediatrician or other physician who has an established relationship with the patient is a prerequisite to surgery. Likewise, informed written consent from the women's legal guardian must include a review of the risks and benefits of and alternatives to the proposed surgery. Our experience suggests that, for selected women with severe mental retardation, hysterectomy, albeit controversial, may improve the quality of life.

Adolescent↗

Anaesthesia and the subclavian steal syndrome.

Anaesthesia in two patients with subclavian steal syndrome is described. Both patients showed an interesting response to hyperventilation. The mechanism of this response and its implications for the anaesthetist are discussed.

Anesthesia, General↗

Rat and mouse monoclonal antibodies to human myelin basic protein.

BALB/c mice and Lewis rats were immunized with human myelin basic protein and its N- and C-terminal fragments. Mouse X mouse fusions produced seven monoclonal antibodies, all of the IgG class and directed against the N-terminal fragment. Five of the antibodies seemed to be against the same epitope, between amino acid residues 92 and 118. One antibody bound between residues 45 and 91, and the remaining antibody reacted with both peptides 1-44 and 45-91. Three monoclonal antibodies, all of the IgM class, were obtained by rat X rat hybridization. Two monoclonal antibodies, raised against whole myelin basic protein and the C-terminal fragment, respectively, each bound to peptide 118-178. The remaining antibody, raised against the N-terminal fragment, bound to peptide 45-91. These monoclonal antibodies are of interest for use in clinical radioimmunoassays and for immunohistochemical investigation of the structural relationships of the myelin sheath.

Animals↗

Pernicious anaemia and mucosal endocrine cell proliferation of the non-antral stomach.

There is a recognised association between pernicious anaemia and the development of gastric carcinoma, endocrine cell hyperplasia, and carcinoid tumour. Multiple endoscopic biopsies from the body mucosa of seven patients with pernicious anaemia showed small intestinal metaplasia with varying degrees of inflammation, fibrosis, and expansion of the lamina propria. Using conventional silver and lead stains, endocrine cells were inconspicuous. Staining for the general neural and neuroendocrine markers NSE and PGP 9.5 revealed a proliferation of endocrine cells in the epithelium and isolated clumps of endocrine cells in the lamina propria. The clumps were composed of two cell types, either small or large. Some of these endocrine cells showed gastrin, 5HT, VIP and substance P immunoreactivity of varying intensity. Ultrastructurally nine morphologically distinct types of granules were found some of which correlated with the immunohistochemistry. Some separate islands were composed solely of endocrine cells while others had a definite neural component, suggesting that the former arise from 'budding off' of enteroendocrine cells and the latter originate from the neuroendocrine cells of the lamina propria plexus. Thus there may be a dual origin of carcinoid tumours. Carcinoid tumours associated with pernicious anaemia tend to be multifocal and are infrequent. Less than 50 such cases have hitherto been reported. Our findings of endocrine cells proliferations in seven cases of pernicious anaemia indicate that this may be an adaptive change that occurs frequently and provides the basis on which carcinoids, less frequently, develop.

Adult↗

Circulating antibodies to mouse monoclonal immunoglobulins in normal subjects--incidence, species specificity, and effects on a two-site assay for creatine kinase-MB isoenzyme.

With a two-site CK-MB assay, we screened serum samples from 1008 blood donors for the presence of antibodies to mouse monoclonal immunoglobulin. These antibodies were capable of cross-linking the labeled antibody with the solid-phase antibody in the two-site assay, thus generating a falsely high apparent CK-MB concentration. In 92 (9.12%) of the blood donors tested, apparent CK-MB concentrations of 10-1000 micrograms/L decreased to less than 3 micrograms/L when re-assayed with non-immune mouse serum (10 mL/L) included in the assay reagent. We tested the ability of non-immune sera from other animal species to lower the concentration of apparent CK-MB in 58 of the 92 samples. Bovine and ovine serum were almost as effective as mouse serum; feline, canine, and rabbit serum were less effective. Of the samples tested, 12% (1.1% of the original population screened) showed apparent CK-MB values that either were not depressed by bovine serum or were only partly depressed. We discuss the possible etiology of these antibodies in normal subjects and recommend that all mouse monoclonal two-site assays should contain non-immune mouse serum (or a suitable "irrelevant" mouse monoclonal antibody) to prevent false-positive results.

Adult↗

An ATP-dependent supercoiling topoisomerase of Chlamydomonas reinhardtii affects accumulation of specific chloroplast transcripts.

We have found that Chlamydomonas reinhardtii cells contain an ATP-dependent topoisomerase activity that supercoils circular DNA in vitro. Subsequent addition of a type I topoisomerase eliminates the supercoils. Like bacterial gyrase, this activity is inhibited by low concentrations of novobiocin (less than 0.1 microM) and by nalidixic acid (less than 0.1 microM). We have examined the effects of these topoisomerase inhibitors on accumulation of various chloroplast transcripts in vivo. Novobiocin differentially affected such transcripts; some transcripts became more abundant while many others were reduced in the presence of this drug. Nalidixic acid on the other hand caused many transcripts to become more abundant albeit to varying degrees. Inhibitors of this algal topoisomerase specifically stimulate a family of related transcripts which we have previously shown to be under light-dark control. We discuss how the inhibitors of this topoisomerase might exert their in vivo effects.

Chlamydomonas↗

Missouri Children's Behavior Checklist profiles with developmentally disabled children: construct validity.

The clinical utility and construct validity of seven new MCBC behavior profiles were evaluated and compared to the original four behavior profiles. The relationship between the seven new behavior profiles and the clinical findings and recommendations that stem from an interdisciplinary evaluation of children referred to a clinic for development disabilities was determined. The seven cluster solution classified equally as well as the four cluster solution, but with increased differentiation into more specific internalizing and externalizing behavior profile subgroups. Construct validity information was provided for several of the new profiles in terms of the association with clinical findings of behavior problems and recommendations for therapy.

Aggression↗

Neural markers in carcinoma of the lung.

Small cell carcinoma (SCC) is considered to be of neuroendocrine origin. Neurone specific enolase (NSE) and PGP 9.5 are markers of neural and neuroendocrine differentiation. S-100 protein is a marker of glial differentiation. The expression of these markers in endobronchial biopsy and lung tumour resection specimens was studied to see if any diagnostic, prognostic or therapeutic implications would emerge. Zamboni fixed endobronchial tumour biopsy specimens from 20 patients were examined. Twelve of these were cases of SCC and 8 were non-SCC. Of the 12 SCC, 7 were positive for NSE, 6 for PGP 9.5 and 5 for S-100 protein. Cases which showed a positive reaction for NSE had a mean survival of 9.1 months compared with 3.9 months for those with a negative reaction, but the number of cases is too small to assign any statistical significance. There was no difference in survival times between positive and negative reactors for PGP 9.5 and S-100 protein. All 8 cases of non-SCC showed positive reactions to all three markers. Of 32 formalin fixed lung tumour resection specimens 6 were cases of SCC, 25 non-SCC and 1 a chemodectoma. Three of the 6 cases of SCC showed positive staining for NSE, 3 for PGP 9.5 and 1 for S-100 protein. Of the 25 non-SCC, 10 were positive for NSE, 12 for PGP 9.5 and 6 for S-100 protein. The 1 chemodectoma stained positively for all three markers. Neuroendocrine markers are of little value in differentiating SCC from non-SCC. Positive staining for NSE in SCC may be an indicator of prolonged survival but further investigation is required.

Adenocarcinoma↗

;Dark-Lethality' of Certain Chlamydomonas reinhardtii Strains Is Prevented by Dim Blue Light.

Cells of certain Chlamydomonas reinhardtii strains dramatically swell and ultimately disintegrate when grown in the dark but not in the light. This effect of darkness is delayed: cells undergo about two divisions before swelling. Measurements on O(2) uptake and ATP content indicate that the cells grown in the dark are not deficient in energy supply. Dim blue light not effective in photosynthesis prevents ;dark-lethality'. Inhibition of protein synthesis during the latent period with cycloheximide also prevents dark-lethality. We propose that blue light stimulates synthesis of one or more proteins which are part of or are important in assembly of an osmoregulatory complex.

Journal Article↗

PGP 9.5, a new marker for human neuroendocrine tumours.

PGP 9.5 is a soluble protein isolated from brain and is a general marker for neuronal and neuroendocrine tissue. Its function is not known. Until now neurone specific enolase (NSE) has been the only general marker for the paracrine system and tumours derived from it. Seventy-four neuroendocrine tumours, 17 melanocytic naevi, 51 melanomas and four granular tumours were stained immunohistochemically for PGP 9.5 and NSE. A variety of pulmonary and non-neuroendocrine tumours were also stained. Two so-called goblet cell carcinoids of the appendix were included in the series. Using NSE 59/74 neuroendocrine tumours were positive and 58/74 stained for PGP 9.5. In combination 63/74 of these tumours were positive for either NSE or PGP 9.5 or both. Staining for PGP 9.5 was better for demonstration of nerves in routinely processed material than was staining for NSE. Twenty-one out of 43 primary melanomas stained for PGP 9.5 and 36 showed staining for NSE. Only two of eight metastatic melanomas melanocytic stained for PGP 9.5 while seven of these eight stained for NSE. Six of 17 melanocytic naevi stained for PGP 9.5 and five stained for NSE. All four granular cell tumours stained for PGP 9.5 and NSE. Both "goblet cell carcinoids' of the appendix were negative for NSE and PGP 9.5. Fifteen out of 32 pulmonary cancers showed staining for either marker and no non endocrine tumour showed any specific staining. Staining for PGP 9.5 is a valuable additional probe in the exploration of the paracrine system and the diagnosis of tumours arising from it.

Humans↗

Immunoassay of the neuronal and neuroendocrine marker PGP 9.5 in human tissues.

An inhibitory, coated-well immunoassay for the neurone-specific protein PGP 9.5 has been devised and used to measure the concentrations of the protein in human tissues. Concentrations of PGP 9.5 between 40 ng/ml and 10 micrograms/ml could be measured using this assay. In brain PGP 9.5 was present at 100.58 +/- 16.18 micrograms/mg protein. Of the other organs examined only kidney and testis showed significant concentrations of PGP 9.5 (3.97 +/- 0.87 microgram/mg protein and 3.25 +/- 0.36 microgram/mg protein, respectively). All other organs contained less than 2% of the brain level. The tissue levels determined by coated-well immunoassay confirmed the tissue specificity of PGP 9.5 originally determined by high-resolution two-dimensional gel electrophoresis.

APUD Cells↗

A comparison of the evolutionary distribution of the two neuroendocrine markers, neurone-specific enolase and protein gene product 9.5.

One- and two-dimensional polyacrylamide gel electrophoresis followed by immunoblotting has been used to examine the phylogenetic distribution of the two neuronal and neuroendocrine proteins, neurone-specific enolase and protein gene product 9.5, in animal brains. A new immunoblotting procedure was used in which complex two-dimensional patterns of brain proteins were transferred to nitrocellulose paper simultaneously with the Coomassie Blue stain. This produced a copy of the blue spot pattern against which brown protein spots reacting in a specific antibody-immunoperoxidase procedure could be identified unequivocally. Extracts of human, bovine, sheep, rabbit, rat, guinea-pig, chicken, trout, and frog brains were examined. Proteins cross-reacting with antisera to the human forms of both proteins could be demonstrated in all species examined. This suggests that proteins corresponding to neurone-specific enolase and protein gene product 9.5 could have evolved at least 400 million years ago and have been highly conserved throughout evolution.

Animals↗

The stability of creatine kinase isoenzymes studied with two-site monoclonal antibody assays.

The stability of human creatine kinase isoenzymes was investigated under different storage conditions using specific two-site monoclonal antibody assays. In Tris-HCl buffer pH 7.5 or barbitone buffer pH 8.1 containing 5 g/L bovine serum albumin, the isoenzymes appeared to be stable for up to 3 weeks at 4 degrees C but suffered a partial subunit dissociation and random reassociation after freeze-thawing; this dissociation was more pronounced as a result of freezing at -20 degrees C rather than at -70 degrees C. In contrast, creatine kinase isoenzymes stored in serum were stable at both 4 degrees C and following freeze-thawing. High levels of heart type creatine kinase in serum showed only minor subunit hybridisation even after 12 h at room temperature. We conclude that in practical clinical situations, subunit hybridisation in serum samples is negligible. We recommend however, that isoenzyme standards for use in either two-site assays or radioimmunoassays should be stored frozen in normal serum from which endogenous creatine kinase isoenzymes have been previously removed.

Antibodies, Monoclonal↗