Surface membrane proteins and glycoproteins of red blood cells from normal and anaemic mice

1. The surface membrane proteins of red blood cells from normal, hyperbled or acetylphenylhydrazine-treated BALB/c mice and NZB mice of different ages were labelled by lactoperoxidase-catalyzed radioiodination. Sialoglyoproteins were labelled by periodate/NaB3H4 or galactose oxidase +/- neuraminidase/Na3H4 treatments. 2. Anaemia produced several changes in radioiodinated proteins. 3. Sialoglycoprotein radiolabelling was unchanged, even with over 90% reticulocytosis. 4. Decreased periodate/NaB3H4-dependent labelling of red blood cells from Plasmodium berghei-infected BALB/c mice (Howard et al., 1980; Howard & Day, 1981) cannot therefore be due to anaemia per se, but must be related more specifically with infection.

Studies on malaria in Papua New Guinea: comparison of the surface glycoproteins on red blood cells from infected and uninfected individuals

The levels of erythrocyte membrane sialic acid from 17 patients with Plasmodium falciparum malaria and 1 with Plasmodium vivax malaria, in Papua New Guinea, have been compared with 9 uninfected controls. The amounts of radioactivity incorporated into the major erythrocyte glycoproteins by the periodate/NaB3H4 or galactose oxidase plus neuraminidase/NaB3H4 methods were unchanged by malaria infection. The electrophoretic mobilities of these proteins also were unaffected. Several new glycoprotein bands with molecular weights (mol. wt) of 160,000, 89,000, 46,000, 42,000 and 33,000 Daltons were labelled on the surface of erythrocytes from infected individuals; however, none of these bands appeared in all malarious samples. Sialic acid levels on the erythrocyte membrane were also measured by exhaustive neuraminidase treatment and quantitative assay of released sialic acid. The amount of sialic acid was raised in 1 infected individual, within the normal range for Europeans in 4 others, and below this range with 3 patients. Apparently, extensive removal or modification of sialic acid on the surface of uninfected erythrocytes does not occur in human malaria, in contrast to the results obtained in earlier studies with the lethal murine malarias.

Conservative management of benign oesophageal strictures

Over a four year period, 66 patients have undergone fibreoptic endoscopy and Eder Puestow dilatation for a presumed benign oesophageal stricture. Ten patients were subsequently shown to have carcinoma of the oesophagus. There were 121 dilatations with only one perforation, which healed with conservative treatment. Twenty eight of the 56 patients with a benign stricture have required only one dilatation with relief of dysphagia during follow-up periods ranging from 11 months to 61 months (mean 29 months). In those requiring repeat dilatations, relief has been obtained for periods ranging from two weeks to 35 months (mean 6 months). Mean time to restricture in the carcinoma group was two weeks. We conclude that the Eder Puestow method is safe, well tolerated, and less than 5% will require surgery. Strictures which recur rapidly should arouse suspicion of malignancy.

Endoscopic insertion of palliative oesophageal tubes in oesophagogastric neoplasms

Fifty-five patients have undergone fibreoptic endoscopy under diazepam sedation with attempted insertion of a Celestin tube by the Nottingham introducer for an unresectable oesophagogastric malignant stricture. There were 4 perforations in 48 successful intubations (8.3 per cent), 3 patients subsequently dying and the fourth healing spontaneously. There were 4 proximal tube displacements; 3 patients later returned with bolus obstruction. Thirty-five (73 per cent) of the 48 patients who were successfully intubated left hospital with relief of dysphagia for periods ranging from 10 days to 18 months until death (mean 5.5 months). Of the 13 deaths in hospital, 6 occurred as a result of the procedure (mortality rate 12.5 per cent). We conclude that endoscopic insertion of palliative oesophagogastric tubes is relatively safe, simple to perform and could replace surgical introduction. It is technically more difficult in cases of gastric neoplasm involving the cardia.

Hepatic and serum ferritin concentrations in patients with idiopathic hemochromatosis

Hepatic iron and ferritin concentrations have been measured in needle biopsy specimens from patients with idiopathic hemochromatosis and from patients with other liver diseases. There was an excellent correlation between liver iron and ferritin concentrations in patients with miscellaneous liver diseases, but this was not found for the patients with hemochromatosis either before or after treatment. The proportion of liver iron bound to ferritin was lower in treated and untreated hemochromatosis than in the other patients. This probably reflects the formation of increasing amounts of hemosiderin with increasing iron deposition. Three patients in the early stage of idiopathic hemochromatosis were studied. These patients had high concentrations of hepatic iron and ferritin, but had serum ferritin concentrations within, or just above, the normal stage. These results suggest that, in the early stage of hemochromatosis, there is no failure of ferritin synthesis in the liver and that normal levels of serum ferritin are present either because the total body iron content is within the normal range or because the liver parenchymal cells are not, in the absence of liver damage, an important source of plasma ferritin.

Characterization of surface proteins and glycoproteins on red blood cells from mice infected with haemosporidia: Plasmodium yoelii infections of BALB/c mice

Lactoperoxidase-catalysed radio-iodination was used to compare the surface proteins on red cells from Plasmodium yoelii-infected with normal BALB/c mice. The profile of radio-iodinated proteins separated by SDS-polyacrylamide gel electrophoresis was different for infected blood of similar parasitaemia from mice inoculated with different doses of the parasite. Inoculation with different doses of the parasite. Inoculation with the lower dose resulted in the appearance of a major radio-iodinated protein of apparent molecular weight (Mr) 76 000 which was labelled to a similar extent on uninfected red cells from infected blood and purified multinucleate infected cells. Several minor radio-iodinated bands, with identical mobilities to the minor bands on normal BALB/c erythrocytes, were also present on red cells from this infected blood. In contrast, the higher inoculation dose produced changes in the minor labelled bands, and the band with Mr of 76 000 was absent. In this case, the minor radio-iodinated proteins of the normal BALB/c erythrocyte (with Mr of 65 000, 57 000, 48 000, 38 000 and 32 000) were replaced by a series of bands with Mr of 60 000, 50 000, 43 000 and 28 000 on both uninfected and infected red cells. These differences with inoculation dose may be related to the different duration of these infections, the development of anaemia and the extent of pathological changes at the erythrocyte surface. P. yoelii infection caused a marked loss in periodate-dependent labelling of sialoglycoproteins on most, if not all, red cells in infected blood. There was also a large decrease in galactose oxidase-dependent glycoprotein labelling with or without neuraminidase treatment. These changes in the carbohydrate groups on red cell membrane glycoproteins may be linked to the excessive loss of both uninfected and infected red cells during some malaria infections.

Characterization of surface proteins and glycoproteins on red blood cells from mice infected with haemosporidia: Plasmodium berghei infections of BALB/c mice

The surface proteins and glycoproteins of red cells from Plasmodium berghei-infected blood have been radio-isotope labelled and compared with those of normal mouse erythrocytes using the following protein labelling probes: lactoperoxidase-catalysed radio-iodination of tyrosyl residues, periodate oxidation and NaB3H4 reduction of sialic acid and oxidation of galactosyl/N-acetylgalactosaminyl residues by galactose oxidase with subsequent NaB3H4 reduction. During P. berghei infection, new tyrosyl-labelled proteins with apparent molecular weights (Mr) of 60 000, 54 000, 40 000 and 27 500 appeared on the surface of most, if not all, red cells in the blood. Purified multinucleate cells (mostly reticulocytes) differed only in that they also had a surface protein with Mr of 83 000. However, this molecule is thought to be specific to mouse reticulocytes rather than derived from parasites. In contrast to the relatively minor changes detected with radio-iodination, striking changes in glycoprotein radio-isotope labelling resulted from infection. All of the red cells in infected blood of greater than 20% parasitaemia lost their periodate-sensitive glycoprotein sialic acid. With some samples there was little change in glycoprotein labelling by the galactose oxidase method, provided neuraminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infected cells which has been inferred in many haemosporidial infections, including malaria.

Characterization of surface proteins and glycoproteins on red blood cells from mice infected with haemosporidia: Babesia rodhaini infections of BALB/c mice

Infection of intact (nu/+) or hypothymic (nu/nu) BALB/c mice with the lethal intra-erythrocytic parasite, Babesia rodhaini, induced several changes in the surface proteins of red cells from infected blood. Lactoperoxidase-catalysed radio-iodination was used to compare the surface proteins on normal mouse erythrocytes and the total red cells from infected blood at different levels of parasitaemia. At very low parasitaemia, when only 2.5% of the red cells contained parasites, we observed significant changes in the profile of radio-iodinated proteins separated by SDS-polyacrylamide gel electrophoresis. These changes included the appearance of a group of high molecular weight proteins, and a protein with an apparent molecular weight (Mr) of 60 000, both of which were absent from normal erythrocytes. The major labelled band on the erythrocyte surface (Mr 92 000) also appeared to be less heavily labelled during infection. The magnitude of these differences in surface proteins increased as the parasitaemia rose, until the new bands dominated the radioactivity profile with blood of greater than 50% parasitaemia. Several control experiments established that the radio-iodinated proteins were surface molecules on intact cells and that artifactual proteolysis did not contribute to the observed differences. The results suggest that changes in the surface proteins occur on all red cells in the blood of infected mice. The results of labelling the surface glycoproteins by oxidation with periodate or galactose oxidase, followed by NaB3H4 reduction, have varied with the isolate of B. rodhaini. With the isolate currently in use, no significant differences were observed in the labelled surface glycoproteins of normal erythrocytes and red cells from infected blood of high parasitaemia, whereas an earlier isolate exhibited a marked decrease of glycoprotein labelling of both infected and uninfected red cells.

Jaundice following warfarin therapy

A case of intrahepatic cholestatic jaundice following warfarin therapy is described. The patient made a complete recovery on withdrawal on the drug.

Controlled trial of cimetidine in upper gastrointestinal haemorrhage

One hundred and one patients were studied in a double-blind controlled trial to assess the role of oral cimetidine in preventing the continuation or recurrence of acute upper gastrointestinal haemorrhage from various sources, chiefly peptic ulcer. The dose of cimetidine was 800 mg on entering the study followed by 400 mg six hourly. The source of bleeding was identified endoscopically in 96% of patients, peptic ulcer comprising 70%. Bleeding continued or recurred in 11 of 51 (21.5%) of patients on cimetidine and in 12 of 50 (24%) of patients on placebo. Analysis of the effect of cimetidine according to age or severity of bleeding showed no significant advantage for the drug.

Identification of differences between the surface proteins and glycoproteins of normal mouse (Balb/c) and human erythrocytes

The topography of the external surface of the Balb/c mouse erythrocyte has been investigated and compared to the human erythrocyte by using a series of protein radiolabeling probes. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the pattern of Coomassie Blue stained proteins was very similar for mouse and human erythrocyte ghosts, as was the distribution of radioactivity in protein bands after lactoperoxidase catalyzed radioiodination. The mouse erythrocyte glycoproteins identified by periodic-acid-Schiff and 'Stains-All' reagents, sialic acid analysis of gel slices, binding of 125I-wheat germ agglutinin and 125I-concanavalin A to the gels, and glycoprotein radiolabeling techniques, differed markedly from the sets of proteins labeled by radioiodination, and also differed from the human erythrocyte glycoproteins. Instead of the PAS I to PAS IV series of sialoglycoproteins characteristic of human erythrocytes, the mouse erythrocyte possesses a broad band of sialoglycoproteins with several peaks ranging in mol wt from 65,000 to 32,000. The same group of sialoglycoproteins were labeled by the periodate/B3H4-technique specific for terminal sialic acid, and the galactose oxidase/B3H4-method (plus neuraminidase) specific for galactosyl/N-acetylgalactosaminyl residues penultimate to sialic acid. These results emphasize the necessity to employ a variety of protein radiolabeling probes based on different labeling specificities, to study the membrane topography of cells which are poorly understood compared to the human erythrocyte membrane.

Optimal conditions for lactoperoxidase catalyzed radioiodination of external proteins on mouse erythrocytes

Optimal conditions were established for specific labelling of the surface proteins of mouse erythrocytes using lactoperoxidase-catalyzed radioiodination. The levels of H2O2 and I-, and cell concentrations required for restriction of haemoglobin labelling to less than 5% of the total 125I-protein, were different for radioiodination employing direct H2O2 addition or generation of H2O2 with glucose oxidase plus glucose. Preparation of mouse erythrocyte ghosts by hypotonic lysis caused loss of some minor labelled proteins present on intact cells and shifts to lower molecular weights of others. It is therefore important to solubilize labelled cells directly in electrophoresis buffer to avoid artifactual degradation of labelled proteins. The extent of labelling internal cell proteins was measured by a procedure suitable for the comparison of a large number of samples: solubilized radioiodinated erythrocytes were electrophoresed on 14% acrylamide gels and the radioactivity determined in the haemoglobin band which migrates separately from other proteins. The major labelled protein on the mouse erythrocytes had an apparent molecular weight of 92,000, and may be analogous to Band 3 of the human erythrocyte.

Naturally occurring antibodies to liposomes. I. Rabbit antibodies to sphingomyelin-containing liposomes before and after immunization with unrelated antigens

Liposomes were prepared from a mixture of sphingomyelin, cholesterol, and dicetylphosphate or L-alpha-dimyristoyl phosphatidylcholine, cholesterol, and dicetylphosphate, in the presence of glucose. The amount of trapped glucose released from these liposomes was monitored after incubation with a variety of normal and immune sera in the presence of guinea pig complement. All normal rabbit sera tested were found to release, in the presence of complement, detectable amounts of trapped glucose from sphingomyelin-containing liposomes. After immunization with a variety of unrelated antigens, the anti-sphingomyelin liposome activity increased signficantly and in direct proportion to the number of injections, despite the fact that the liposomes used in the assay did not contain the relevant antigen used for immunization. Liposomes prepared from dimyristoyl phosphatidylcholine showed only marginal release of their trapped marker when assayed with the same rabbit sera and complement. These liposomes, however, were fully reactive when the appropriate antigen was inserted in their bilayer structure. The antiliposome activity was associated mainly with the IgM antibody class. These results raise the interesting possibility that antigenic stimulation may trigger the activation of lymphocyte clones directed against autologous cell-membrane components that cross-react with artificial model membranes containing sphingomyelin.

Abnormal blood vessels in the gastric antrum: a cause of upper-gastrointestinal bleeding

Three patients who bled from curious vascular lesions of the gastric antrum are described. Each presented with an iron-deficiency anemia. Histological examination in two of the patients demonstrated numerous ectatic submucosal vessels in the antrum, the appearances being somewhat similar to angiodysplasia of the colon. The gastric lesions were not shown by barium meal examination or angiography but gave characteristic appearances on endoscopy. We believe that Billroth I partial gastrectomy is the treatment of choice for this condition.

Double-blind comparison of cimetidine and placebo in the maintenance of healing of chronic duodenal ulceration

Patients suffering from chronic duodenal ulceration were allocated at random to treatment with either cimetidine (400 mg twice daily) or matching placebo for six months. Before entry to the trial all patients were shown to have healed ulcers on endoscopy. Most of the patients had participated in a one-month trial of cimetidine during which their ulcers healed. The trial showed that four of 29 patients relapsed on maintenance treatment with cimetidine, which therefore did not confer complete immunity from relapse. However, cimetidine treatment was very much better than placebo treatment, on which 18 of 31 patients relapsed. Of the 22 patients who relapsed clinically, 20 were submitted to endoscopy and 19 of these were shown to have ulcerated again. Endoscopy at the end of the trial showed that ulcers had also redeveloped in five of 28 asymptomatic patients. Length of previous dyspeptic history had no bearing on the results of the trial but there was evidence that relapse on placebo was less likely if the ulcer had originally healed on a high dose of cimetidine. Clinical relapse was associated with worsening duodenitis. Symptoms, clinical observation, and laboratory tests showed no important abnormalities in the patients.

Portal hypertension in vinyl chloride monomer workers. A hemodynamic study

Hemodynamic studies were performed in 5 vinyl chloride monomer workers in whom splenomegaly or thrombocytopenia was detected during a screening program at major chemical plant. Three patients had portal hypertension and collateral venous circulations, with intrasplenic pressures between 20 and 29 mm Hg and normal wedged hepatic venous pressures, but the gradient between the wedged and free hepatic vein pressures was also increased. Splenic blood flows were increased in both hypertensive and normotensive patients. There was no correlation between the splenic blood flow and the portal pressure or the presence of portal fibrosis. The portal hypertension associated with vinyl chloride exposure is mainly presinusoidal in type, and may be attributed to an abnormality of the portal vein radicles, or hepatic sinusoids.

Congenital hepatic fibrosis and choledochus cyst

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Percutaneous cholangiography with the Okuda needle

Percutaneous cholangiography with the Okuda needle was performed in 42 consecutive patients with a clinical diagnosis of obstructive jaundice. Six had intrahepatic cholestasis. The technique demonstrated the biliary anatomy in 41 patients and the radiological diagnosis was confirmed by laparotomy, necropsy, or liver biopsy. There were no significant complications. Laparotomy, when indicated, was performed earlier in the course of the jaundice and it was avoided in seven patients. Precise knowledge of the site of the obstruction was of great help to the surgeon. We believe that this technique represents an important advance in the management of the jaundiced patient.

Lymphosarcoma in Crohn's disease: report of a case

In a patient who had a family history of ulcerative colitis and colonic carcinoma, a jejunal lymphosarcoma developed four years after resection for Crohn's disease of the small intestine. It is suggested that the association of lymphosarcoma with Crohn's disease is more than a chance association.

Percutaneous transhipatic cholangiography

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Portal hypertension in vinyl-chloride production workers

Portal hypertension was seen in seven patients who had been involved in the production of vinyl-chloride monomer for 4-15 years. Four presented with bleeding oesophageal varices. In liver biopsy specimens non-cirrhotic portal fibrosis was inconspicuous and was seen more clearly on wedge rather than needle biopsy specimens. The intrahepatic venous pattern was hardly distrubed. Three patients have done well following shunt surgery. In one patient an angiosarcoma developed, but fibrosis was a more common lesion and was probably not pre-malignant.

A double blind trial of gefarnate and placebo in the treatment of gastric ulcer

Forty-five patients with chronic gastric ulcers were treated as out-patients in a double-blind comparison of gefarnate (geranyl farnesylacetate), 50 mg four times daily, with the same number of dummy capsules daily for five weeks. The mean percentage reduction in ulcer size assessed by radiography was 70-4 per cent in the gefarnate patients compared with 27-8 per cent in those receiving placebo capsules. This difference is statistically significant (p less than 0-05, with a two-tailed test). No change in the electrolyte balance occurred in any of the patients and no side-effects were reported. These results suggest that gefarnate promotes the healing of gastric ulcers in ambulant patients. Its apparent absence of side-effects makes it a safe ans useful drug.

Monitoring liver disorders in vinyl chloride monomer workers using greyscale ultrasonography

Recognition that vinyl chloride could be hepatotoxic led to a survey of workers to determine whether changes had been induced by past exposure, and to evaluate standard liver function tests as monitors of early liver abnormalities. Standard liver function tests were found to be unsuitable for the detection of such abnormalities in the population at risk. Of 487 workers examined, 102 (20-9%) had abnormalities on initial testing but only two were finally shown to have portal hypertension; in both cases, thrombocytopaenia provided the first diagnostic evidence since liver function tests were normal. Furthermore, 40 (35-7%) of 112 control subjects had initial test abnormalities. A sample of 19 workers with various exposures to vinyl chloride monomer were examined blind by greyscale ultrasonography. Five with minimal or no exposure were confirmed as normal but 12 of the remainder had abnormalities. These consisted of an enlarged portal vein (seven instances), splenomegaly (eight), and changes in hepatic texture (seven). Five of these 12 cases had previously been considered normal. It was concluded that greyscale ultrasonography had many advantages over standard methods for screening workers exposed to hepatotoxic chemicals, and should be the subject of a large scale evaluation.

Hepatic angiosarcoma in a vinyl chloride worker

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Preliminary results of grey-scale ultrasonography in the detection of vinyl chloride related liver and spleen disease

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Grey-scale ultrasonography for monitoring industrial exposure to hepatotoxic agents

Industrial exposure to several potentially hepatotoxic agents, such as vinyl-chloride monomer may occur, and there is a need for non-vasive, diagnostic techniques to detect and monitor progressive pathological processes in liver or spleen. Grey-scale ultrasonography permits display of detailed anatomy and pathology in the liver, portal veins, and spleen. The combination of fine resolution, non-invasiveness, absence of ionising radiation hazard, and portable equipment makes the technique ideal for screening populations at risk.

Lipodystrophy, pancreatitis, and eosinophilia

Two patients suffering from partial lipodystrophy, pancreatitis, and recurrent eosinophilia are described. In one patient the duodenum and the terminal ileum were narrowed, the appearances suggesting eosinophilic gastroenteritis: bilateral hydronephrosis was also present without ureteric obstruction. An association between lipodystrophy and renal disease is recognized; it is possible that there is also an association between lipodystrophy and pancreatitis, and eosinophilia with or without an intestinal lesion may be a further association.

A double blind trial of carbenoxolone and geranyl farnesyl acetate in gastric ulcer

57 patients with a chronic gastric ulcer were treated as outpatients in a double blind comparison of carbenozolone 100 mg three times daily with the same dose of geranyl farnesyl acetate (Gefarnate). Healing rates for carbenoxolone were better than for gefarnate, but not significantly so. Nearly half the carbenoxolone-treated patients developed hypokalaemia or oedema, whereas no similar side-effects were found with gefarnate. Gefarnate, while not as effective as carbenoxolone, does appear to promote gastric ulcer healing. Its virtual absence of side-effects makes it a safe and useful drug.