Naturally occurring antibodies reacting with lipoic acid: screening method, characterization and biochemical interest

The development of a covalent enzyme-linked immunoassay (CELIA) using lipoic acid covalently bound to modified polystyrene microplates has permitted the detection, in the sera of normal BALB/c mice, of natural antibodies reacting with lipoic acid (LA). Hybridomas producing monoclonal anti-LA antibodies were obtained from splenocytes of non-immune BALB/c mice. Two of them, of IgM isotype, recognized LA but failed to react with dihydrolipoic acid (DHLA, the reduced form of LA), suggesting that the integrity of the dithiolane ring was of importance for antibody recognition. They did not give positive reactions with other disulfide linked biological molecules such as oxidized glutathione or cystine. Anti-LA antibodies, coated on polystyrene microplates, were used for the detection of free LA in a competitive assay based on peroxidase-LA conjugate.

Stelazine-induced pigmentation

A case of a West Indian patient is reported who developed abnormal blue-grey pigmentation on exposed areas of skin following treatment with low dose stelazine. Oculocutaneous melanosis is a well-recognized side-effect of prolonged phenothiazine treatment. In this condition the areas of skin exposed to sunlight develop a violaceous, blue-grey or slate-grey colour in more severe cases. These characteristic changes are rarely seen now. We describe the case of a patient who developed pigmentation while taking a low dose of stelazine for 5 years.

Inhibition of type 5 adenovirus infectivity by periodate oxidation

Periodate oxidation of purified type 5 Adenovirus (Ad5) led to a mean loss of infectivity of 6.84 logs. There were no significant differences in adsorption and penetration between oxidized and mock-oxidized virus. However, after infection with oxidized virus, no synthesis of viral structural proteins could be detected and a 78.5% inhibition of viral DNA synthesis was observed. Labelling experiments performed by treating oxidized and mock-oxidized virus with tritiated sodium borohydride revealed that the fiber glycoprotein was one of the proteins labelled in oxidized virus whereas no labelled proteins were detected in non oxidized virus. In addition, it was found that one mol of formaldehyde generated during oxidation of sugar residues was bound per 500 base pairs in oxidized virus. One consequence of this in situ generation of formaldehyde is the formation of DNA-protein crosslinks. The DNA so crosslinked showed different patterns of restriction fragments with endonucleases such as Hpa I, Hind III and Kpn I but not with Xho I.

Rectal varices in extrahepatic portal hypertension

Rectal varices, as distinct from haemorrhoids, occur due to high pressure in the inferior mesenteric venous system in patients with portal hypertension. The exact prevalence of rectal varices in extrahepatic portal hypertension is unknown. To determine this, 116 patients with extrahepatic portal hypertension were studied for the presence of rectal varices. These lesions were found in 103 (88.8%) patients. Bleeding from rectal varices occurred in 14.6% of patients. Massive bleeding requiring hospitalization and blood transfusion was not encountered. It is concluded that rectal varices are common in extrahepatic portal hypertension. Bleeding from them is uncommon, and often mild and self-limiting. The available literature is reviewed and the importance of recognizing the condition stressed.

Covalent linking of haptens, proteins and nucleic acids to a modified polystyrene support

Biological molecules of various molecular weights were successfully linked to polystyrene microtitration plates bearing carbonyl and hydroxyl reactive groups. Cross-linking of proteins, nucleic acids and haptens was carried out with water soluble carbodiimide. The covalent nature of the binding reaction was demonstrated by the immunodetection of a hapten linked to the surface through a disulphide spacer arm and its subsequent release by cleavage of the bridge. The amount of protein fixed per surface unit could be correlated to molecular weight. Nanograms of biotinylated nucleic acids and synthetic polynucleotides could also be retained on the solid support.

An open evening for stroke patients and relatives

A cerebral vascular accident (CVA) can cause fear and anxiety about the future for both sufferer and carers. Returning to the community after having been in the security of a hospital ward for many weeks can be traumatic. Nurses should enhance their health education programmes to prepare stroke patients and relatives for life at home.

Colonoscopic study of 50 patients with colonic tuberculosis

Fifty patients with colonic tuberculosis are reported in whom a colonoscopic diagnosis confirmed by histological examination was possible in 40. Bacteriological studies did not increase the diagnostic yield. Abdominal pain was the most common symptom (90%) and an abdominal mass the most common abnormal physical finding (58%). A nodular mucosa with areas of ulceration was the usual colonoscopic finding. Ileocaecal disease was found in 16, ileocaecal and contiguous ascending colon disease in 14, segmental colonic tuberculosis in 13, ileocaecal disease and non-confluent involvement of another part of the colon in five, and pancolitis in two patients. This report emphasises that colonoscopy is a useful procedure for diagnosing colonic tuberculosis and that segmental colonic tuberculosis is not uncommon.

Cancer family syndrome associated with multiple malignant melanomas and a malignant fibrous histiocytoma

A 64-year-old female with the cancer family syndrome suffered from multiple malignant melanomas and a malignant fibrous histiocytoma. She has shown unusually long survival which is a feature of these patients.

Antifungal effects of the nonlinear pharmacokinetics of cilofungin, a 1,3-beta-glucan synthetase inhibitor, during continuous and intermittent intravenous infusions in treatment of experimental disseminated candidiasis

Cilofungin (LY-121019) is a fungicidal cell wall-active 1,3-beta-glucan synthetase inhibitor with a short plasma half-life and saturable nonlinear plasma pharmacokinetics. To optimize the in vivo efficacy of this compound, we studied the effects of its linear and nonlinear pharmacokinetics during continuous versus intermittent intravenous infusion of cilofungin in the treatment of experimental disseminated candidiasis in persistently granulocytopenic rabbits. Six groups of rabbits were studied, untreated controls (n = 32) and five cilofungin dosage regimen groups consisting of the following: 25 mg/kg of body weight intravenously twice daily (VLoINT) (n = 9); 50 mg/kg twice daily (LoINT) (n = 9); 90 mg/kg twice daily (HiINT) (n = 11); 5 mg/kg/h for 18 h/day (LoCI) (n = 7); and 10 mg/kg/h for 18 h/day (HiCI) (n = 7). All regimens achieved plasma concentrations exceeding the MIC for Candida albicans (0.25 microgram/ml). In vitro timed kill assays found that the fungicidal activity and rate of kill by cilofungin above the MIC for C. albicans was concentration dependent. At the lower dosage regimens (VLoINT, LoINT, and LoCI), cilofungin followed linear plasma pharmacokinetics, whereas at higher doses (HiCI and HiINT), nonlinear kinetics consistent with a saturated elimination pathway(s) were observed. Only HiCI and HiINT produced a 10(3)- to 10(4)-fold reduction in CFU per gram in candidiasis of the brain (P less than or equal to 0.001). HiCI and HiINT also significantly reduced infection in the choroid (P less than or equal to 0.05). All regimens, except VLoInt, significantly (P less than or equal to 0.01) reduced tissue infections in lung, liver, spleen, and kidney. However, only the regimens with nonlinear saturation kinetics (HiCI and HiINT) produced a 10(6) reduction in the spleen and a > 10(5) reduction of C. albicans in the kidney and liver. A simple doubling of the dosage from LoCI to HiCI resulted in tissue concentrations that were 10 times higher and a 10(2)- to 10(4)-fold-greater antifungal effect. There was a direct correlation (r2 = 0.83) between tissue concentrations of cilofungin and antifungal activity. Thus, continuous and intermittent infusion dosage regimens that elicit nonlinear saturation plasma pharmacokinetics of cilofungin were associated with increased antifungal activity against experimental disseminated candidiasis.

A novel covalent enzyme-linked immunoassay (CELIA) for simultaneously measuring free and immune complex bound antibodies of defined specificity. I. Application to naturally occurring antipolyamine antibodies in human sera

A simple covalent enzyme-linked immunoassay procedure (CELIA) is described for the routine determination of free and immune complex-bound antibodies in sera. Assays for the latter could not have been performed by adsorption ELISA due to the high ionic strength of the reassociating buffer. For the measurement in human sera of free naturally occurring IgG and IgM antibody directed against the hapten spermine, polycarboxystyrene microtiter plates with covalently coupled spermine were used. For the determination of immune complex-bound antipolyamine IgG and IgM antibody titers, serum was first dissociated at pH 2.3 in tubes and then reassociated at pH 8.1 in the wells of a microtiter plate containing covalently bound spermine. The reactivity of anti-spermine antibodies was increased from 2- to 13-fold after dissociation and reassociation compared to that of non-dissociated area. The apparent reaction constant (Rapp.) of free IgG antibodies to spermine in the sera of 19 bronchopulmonary patients with cancer differed significantly from Rapp. values of IgG antibodies having this specificity in ten other patients with non-malignant disease.

A novel covalent enzyme-linked immunoassay (CELIA) for simultaneously measuring free and immune complex bound antibodies with a defined specificity. II. Application to immune complexes containing viral antigens in human sera

The coupling of viral antigens from parainfluenza virus (PIV-1), cytomegalovirus (CMV) and human immunodeficiency virus (HIV-1) to chemically functionalized polystyrene plates has permitted us to develop a covalent enzyme-linked immunoassay (CELIA) for measuring the titers of free antibody (Ab) and immune complex (IC) bound Ab directed against each of these viruses. The method was first validated for experimentally produced IC (PIV-anti-PIV) and then applied to the analysis of IC in human sera. In the case of a renal transplant patient with CMV viremia whose free Ab titers were less than 100, the method unambiguously permitted the IC bound anti-CMV titers to be determined. In the case of a survey for HIV-1 Ab, it also allowed us to identify a sub-group of seropositives with IC anti-HIV. In view of the ease and rapidity with which CELIA can be performed, this technology should enable determinations of IC bound Ab of defined specificity to be undertaken routinely in seroepidemiological surveys.

SCH-39304 in prevention and treatment of disseminated candidiasis in persistently granulocytopenic rabbits

To investigate the potential use of SCH-39304 for the prevention and treatment of disseminated candidiasis in granulocytopenic patients, we studied its in vivo antifungal activity as preventive, early, and late treatments in three models (acute, subacute, and chronic) of disseminated candidiasis in persistently granulocytopenic rabbits. SCH-39304 was an effective as amphotericin B alone and fluconazole alone for the prevention of disseminated candidiasis. SCH-39304 alone and fluconazole alone were as effective as amphotericin B plus flucytosine for early treatment of subacute disseminated candidiasis. When treatment was delayed for 5 days to establish chronic disseminated candidiasis, SCH-39304 was less effective than amphotericin B plus flucytosine. In comparison with different treatment regimens, SCH-39304 was more effective in early and preventive treatment. Thus, SCH-39304 was comparable to treatment control regimens in prevention and early treatment of subacute disseminated candidiasis. SCH-39304 also was most effective in granulocytopenic rabbits with disseminated candidiasis when used for prevention or early treatment.

Experimental basis for use of fluconazole for preventive or early treatment of disseminated candidiasis in granulocytopenic hosts

To determine the potential for the use of fluconazole for prevention and treatment of disseminated candidiasis in granulocytopenic patients, we investigated its activity and pharmacokinetics in models of acute, subacute, and chronic forms of disseminated candidiasis in persistently granulocytopenic rabbits. Fluconazole was administered for systemic prophylaxis, early treatment, and delayed treatment. Single-dose and steady-state plasma pharmacokinetics, tissue penetration, and dose-response studies of the investigational compound were studied in subacutely infected granulocytopenic rabbits. Fluconazole was more effective when used for systemic prophylaxis or early treatment of disseminated candidiasis than for delayed treatment. Fluconazole was as effective as amphotericin B plus flucytosine in preventive and early treatment of disseminated candidiasis but was significantly less effective than amphotericin plus flucytosine in the treatment of chronic candidiasis. Dose-response studies demonstrated that the antifungal effect of fluconazole was dose- and time-dependent. Studies of the pharmacokinetics of fluconazole in rabbits demonstrated a long half-life in plasma and a large volume of distribution, properties that correspond to the attainment of high levels of penetration into tissues at multiple organ sites. We conclude that fluconazole is effective for prevention and early treatment of disseminated candidiasis in persistently granulocytopenic rabbits and that the evaluation of its use in preventive or early treatment of disseminated candidiasis in carefully designed clinical trials is warranted.

Randomised double blind placebo controlled clinical trial of sucralfate and ranitidine in chronic duodenal ulcer

A double blind, randomised, placebo controlled clinical trial was carried out in endoscopically proved chronic duodenal ulcer patients to compare the efficacy of sucralfate and ranitidine. Sucralfate 1 g four times daily and ranitidine 150 mg twice daily were found to be equally effective in inducing ulcer healing (73.1% and 82.1% respectively) during the 6-week treatment period. The rate of recurrence of the ulcer within six months after the initial treatment (84.2% and 82.6%) was also comparable in the sucralfate and ranitidine groups. Sucralfate and ranitidine are equally effective in ulcer healing and prevention of ulcer relapse.

Polyclonal anti-idiotypic antibodies exhibit antigenic mimicry of limited type 1 fimbrial proteins of Escherichia coli

Polyclonal anti-idiotypic antibodies (anti-Ids)(fim) developed against idiotypes on antibodies (Ab-1s) that specifically bind structural, organelle fimbrial proteins of Escherichia coli were able to modulate immune function in anti-Id(fim)-immunized mice. Proliferation or suppression of splenic lymphoid cell responses by polyclonal anti-Ids in tissue culture appeared to be dose dependent. Anti-Ids were able to induce a dose-dependent T-cell-mediated immunity specific for type 1 fimbrial antigen(s) in immunized animals when assessed in vitro, but they failed to elicit in vivo positive ear-swelling skin reactions. Anti-Ids were unable to induce protective immunity against an in vivo infectious challenge with E. coli in anti-Id-immunized adult animals, but they stimulated a specific, secondary antibody response in anti-Id-challenged mice. Anti-Ids stimulated the development of anti-anti-Ids (Ab-3s) specifically binding a fimbrial antigen(s) and revealed the presence of antibody idiotypes binding E. coli adhesin proteins in the 27- to 29-kilodalton range. Results suggest discrete, but subtle, immunomodulatory effects of the anti-Ids and potential vaccinoid properties capable of stimulating a specific humoral and cellular response in vivo.

Time-resolved fluorescence studies on protoporphyrin IX-apohorseradish peroxidase

The hemin moiety of horseradish peroxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7) was removed and the apoprotein reconstituted with the fluorescent protoporphyrin IX. Steady-state and time-resolved fluorescence properties of the HRP(desFe) adduct were examined; the multifrequency phase and modulation method was utilized for lifetime and dynamic polarization studies. The emission spectrum of HRP(desFe) had maxima at 633 and 696 nm. The lifetime of this emission was characterized by a single exponential decay of 16.87 ns at 22 degrees C. Debye rotational relaxation times for HRP(desFe) were determined using both static (Perrin plot) and dynamic (differential phase and modulation fluorometry) methods; these two approaches gave values of 96 and 86 ns, respectively. A spherical protein of HRP's molecular weight and partial specific volume would be expected to have a Debye rotational relaxation time, at 22 degrees C, in the range of 50 to 60 ns, depending upon the extent of hydration. Hence our results indicate that HRP(desFe) is asymmetric; the global rotational relaxation times observed are consistent with those of a prolate ellipsoid with an axial ratio of 3:1.

Time-resolved fluorescence studies on NADH bound to mitochondrial malate dehydrogenase

Time-resolved fluorescence studies on the emission of NADH bound to porcine heart mitochondrial malate dehydrogenase [S)-malate:NAD+ oxidoreductase, EC 1.1.1.37), in the presence and absence of saturating levels of hydroxymalonate, were carried out. The lifetime of NADH bound in the ternary complex was determined to be 9.5 ns compared to 1.74 ns as reported in the literature. Steady-state and dynamic polarization data indicated a Debye rotational relaxation time in the range of 106-109 ns for the dimeric enzyme. This value is significantly larger than that calculated for a spherical protein and is consistent with the asymmetric dimer found by crystallographic studies.

Cumulative dose-response curves for assessing combined effects of salbutamol and ipratropium bromide in chronic asthma

We investigated whether salbutamol (S) and ipratropium bromide (IB) exerted a true additive bronchodilator effect in asthma. In fifteen selected chronic asthmatics, individual cumulative dose-response curves to S and IB were performed on two separate days (linear regression of bronchodilator response (delta FEV1) between 20 and 80% of maximal response, versus log dose), and the dose of S equipotent to the IB dose giving the maximal bronchodilator effect (IBopt) was calculated by interpolation of each S curve. On two other days, each patient received IBopt or the equipotent S dose followed by an additional 400 micrograms S. On day 1 or 2, FEV1 reached 220 +/- 410 ml and 2410 +/- 380 ml (p less than 0.05) after the maximal dose of IB and S respectively. On day 3 or 4 after pretreatment by IB or S an additional 400 micrograms S gave a further increase, which was similar in both series (315 and 320 ml, respectively). FEV1 after combination treatment reached 238 +/- 350 ml and was not significantly different from the maximal effect of S (2440 +/- 290 ml). We conclude that S and IB exert a true pharmacological additive effect, since the combination effect is as great as the maximal effect of the most potent drug (S) and greater than the maximal effect of IB, and that the same additional dose of S gives the same increase after equipotent doses of S and IB.

Cumulative dose-response curves for assessing combined effects of salbutamol and ipratropium bromide in chronic asthma

We investigated whether salbutamol (S) and ipratropium bromide (IB) exerted a true additive bronchodilator effect in asthma. In fifteen selected chronic asthmatics, individual cumulative dose-response curves to S and IB were performed on two separate days (linear regression of bronchodilator response (delta FEV1) between 20 and 80% of maximal response, versus log dose), and the dose of S equipotent to the IB dose giving the maximal bronchodilator effect (IBopt) was calculated by interpolation of each S curve. On two other days, each patient received IBopt or the equipotent S dose followed by an additional 400 micrograms S. On day 1 or 2, FEV1 reached 220 +/- 410 ml and 2410 +/- 380 ml (p less than 0.05) after the maximal dose of IB and S respectively. On day 3 or 4 after pretreatment by IB or S an additional 400 micrograms S gave a further increase, which was similar in both series (315 and 320 ml, respectively). FEV1 after combination treatment reached 238 +/- 350 ml and was not significantly different from the maximal effect of S (2440 +/- 290 ml). We conclude that S and IB exert a true pharmacological additive effect, since the combination effect is as great as the maximal effect of the most potent drug (S) and greater than the maximal effect of IB, and that the same additional dose of S gives the same increase after equipotent doses of S and IB.

Protein-bound polyamines in the plasma of mice grafted with the Lewis lung carcinoma

Protein-bound polyamines were isolated from the plasma of mice using antipolyamine antibodies covalently linked to magnetic latex spheres. Their subsequent separation by polyacrylamide gel electrophoresis (PAGE) showed that in plasma from normal mice, 3 proteins (27, 55 and 82 kDa) carrying polyamines could be visualized, whereas in mice bearing the Lewis lung carcinoma at least 8 other proteins of higher molecular mass (5 of 94, 110, 130, 145 and 160 kDa, and 3 of greater than 170 kDa) had bound polyamines. These protein-bound polyamines could be detected from the first week after tumour graft; they increased during the second and third week but decreased thereafter. These proteins were not bound by immunolatex spheres preincubated with spermine bound to a protein-carrier insulin. Moreover, the appearance of these protein-bound polyamines was not a consequence of the inflammatory process since in mice infected with heat-inactivated Brucella abortus, with the exception of a 65 kDa protein, polyamines were bound to the same proteins found in normal mice. In mice grafted with the Lewis lung carcinoma the concomitant decrease in transglutaminase-mediated polyamine (e.g. putrescine) binding capacity of plasma proteins provides additional evidence for the presence in vivo of polyamines already bound to plasma proteins.

Foreign body in the lung for 45 years without symptoms

Patients with foreign bodies in the bronchopulmonary tree seldom remain asymptomatic for long (Abdul Majid et al. 1976). We report here a patient who aspirated a 22 carat gold safety-pin at 10 years of age and who continues to be free of respiratory symptoms 45 years later.

Does exercise alter anaerobic threshold in coronary artery disease during beta blockade?

The effect of propranolol on cardiac patients undergoing exercise training is reported to increase exercise tolerance and maximum oxygen uptake (VO2 max) but its effect on anaerobic threshold (AT) is unknown. It was the purpose of this study to determine the role of exercise training with propranolol on AT in patients with coronary artery disease (CAD). Eight men and one woman with significant (CAD) were selected for this study. Each patient completed a maximum treadmill stress test (MTST) following the Bruce protocol on propranolol 40-160 mg/day as a control study. Cardiorespiratory variables were measured at rest and at each stage of the treadmill test. These patients underwent an exercise training programme for 12-16 weeks on the same dose of propranolol. Training sessions were for a minimum of 30-40 minutes, 3 times a week, with training heart rate of 75%-85% of the pretraining peak heart rate. Training heart rate ranged from 98 to 128 beats/min. They were retested with a MTST after the training programme, on the same dose of propranolol. AT was calculated noninvasively by measuring respiratory variables every 30 seconds in relation to work increment. AT was identified by measuring the time course of VE, VCO2, VE/VO2, etc. in relation to incremental work. The mean values of VO2, O2P and % VO2 max at AT before and after training on propanolol were as follows: VO2 = 1.43 L/min +/- .25 and 1.86 L/min +/- .44, O2P = 14.35 +/- 2.40 and 18.73 +/- 4.00 ml/beat, % of VO2 max = 68.20 +/- 6.31 and 73.59 +/- 5.84. The mean changes of VO2 O2P, and % of VO2 max were + 0.43 L/min +/- 0.20 (P < .003), + 4.38 +/- 2.55 (P < .003) and +/- 5.07% +/- 4.84 (P < .001). After exercise training on propanolol, the mean peak exercise tolerance time and absolute VO2 max increased by 2.8 min (from 9.0 to 11.8 min) (P < .001) and 22.7% (P < .007), respectively. We conclude that the increase in anaerobic threshold in patients with coronary artery disease may be due to improvement in VO2 max, increased stroke volume, and peripheral O2 extraction.

Responses of cultured cardiac myocytes to lysosomotropic compounds and methylated amino acids

Cardiac myocytes whose lysosomes had been pre-labelled with acridine orange were exposed to either L-amino acid methyl esters (L-leucine or methionine methyl ester) or to ‘lysosomotropic’ weak bases (chloroquine, methylamine, and NH4Cl) for 1 h. Both types of interventions dilated lysosomes equally and inhibited proteolysis to varying degrees. The weak bases produced no apparent alterations in the acridine orange staining, whereas the methylated amino acids induced a marked redistribution of the fluorescent dye from lysosomes into the myoplasm, suggesting that they may have provoked a change in lysosomal membrane permeability. A brief exposure to weak bases failed to enhance acid proteinase secretion into the culture medium but apparently inactivated cellular cathepsin B activity. In contrast, methylated amino acids induced no alterations in acid proteinase activity or the cellular distribution of the two proteolytic enzymes. Lastly, weak bases markedly elevated intralysosomal pH as measured with fluorescein dextran, while only modest rises were observed after amino acid methyl ester treatment. The present observations imply that amino acid methyl esters represent a new class of reagents with actions distinctly different from those of chloroquine and NH4Cl, and they may provide a unique and valuable means of studying secondary lysosomal function in cell culture.

The toxic effects of triorganotin(IV) compounds on the culicine mosquito, Aedes aegypti (L)

The structure-activity relationships of 25 triorganotin(IV) compounds were studied using the 4th instar A. aegypti larvae of the susceptible Liverpool Red-eye strain. The LC50 values of these compounds were compared with those of Malathion, DDT and Temephos. Maximal activities were obtained with tritolyltin chloride and its complexes with triphenyl-phosphine oxide and pyridine N-oxide, dimethyloctyltin- and diethyloctyltin acetates and tributyltin sucrose phthalate. A limited number of the triorganotin compounds was also tested with observed high activity against the 4th instar larvae of a local DDT-tolerant strain and against the 2nd instar larvae and adults of the susceptible strain. Delayed effect studies with both 2nd and 4th instar larvae showed high post-treatment mortality for the latter and, among the range of active compounds, the methyl- and aryltin compounds, in particular, were also found to exhibit high residual activities (100% kill) in laboratory tests conducted up to 10 weeks.

A quantitative and qualitative study of the transglutaminase-mediated insertion of polyamines into plasma proteins from patients with bronchopulmonary cancer

The transglutaminase-mediated incorporation of putrescine into proteins of plasma derived from 44 patients with histologically defined bronchopulmonary cancer was compared with that from an age-matched group of 18 patients hospitalized with non-malignant diseases. Two types of kinetic data were obtained over a range of putrescine concentrations 0.09 mM to 0.6 mM. Whereas the plasma from all the patients of the control group showed linear kinetics, that from only 24 patients of the cancer group showed linear kinetics. The remaining 20 showed kinetics typical of inhibition by excess substrate. PAGE analysis of [14C] putrescine-bound plasma proteins showed around 15 different bands. Among these putrescine-binding proteins, we identified, with the help of corresponding specific antisera, four protease inhibitors: alpha 2-macroglobulin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and antithrombin III.

The esophageal obturator airway. A review

The esophageal obturator airway (EOA) has been considered a beneficial ventilatory technique for use in cardiopulmonary resuscitation (CPR). At present, seven studies in the literature compare the EOA with other means of ventilation in humans; only one is an actual field study of its effectiveness. We reviewed the available literature dealing with the device to define clearly its role in the ventilatory treatment of patients who require CPR. There appears to be no current evidence of the EOA's effectiveness for ventilation in prehospital cardiac arrest, and fatal complications have been reported with its use. The use of the EOA to replace endotracheal intubation in airway management is not substantiated in the literature.

Further analysis of the effect of ultra-violet irradiation on the formation of the germ line in Xenopus laevis

Ultra-violet (u.v.) irradiation of the vegetal pole of newly fertilized eggs has three documented effects: reduction of primordial germ cells (PGCs), cytological damage to the vegetal hemisphere and disruption of the normal mechanism by which the vegetal yolk mass induces the formation of the dorsal axis of the embryo. In this study, we find that 90 degrees rotation of the egg for various periods after irradiation rescues the dorsal axial structures but does not restore the number of PGCs found in the dorsal mesentery of the gut; neither is there any correlation between reduced numbers of PGCs and disruption of cleavage at the vegetal pole. We therefore conclude that the effect on the germ line is separate from the other two phenomena. Secondly, 90 degrees rotation of non-irradiated eggs was found to significantly reduce germ cell numbers migrating in the dorsal mesentery of the gut.

Further analysis of the effect of ultra-violet irradiation on the formation of the germ line in Xenopus laevis

Ultra-violet (u.v.) irradiation of the vegetal pole of newly fertilized eggs has three documented effects: reduction of primordial germ cells (PGCs), cytological damage to the vegetal hemisphere and disruption of the normal mechanism by which the vegetal yolk mass induces the formation of the dorsal axis of the embryo.

In this study, we find that 90° rotation of the egg for various periods after irradiation rescues the dorsal axial structures but does not restore the number of PGCs found in the dorsal mesentery of the gut; neither is there any correlation between reduced numbers of PGCs and disruption of cleavage at the vegetal pole. We therefore conclude that the effect on the germ line is separate from the other two phenomena.

Secondly, 90° rotation of non-irradiated eggs was found to significantly reduce germ cell numbers migrating in the dorsal mesentery of the gut.

Primordial germ cells of Xenopus embryos: the role of fibronectin in their adhesion during migration

Primordial germ cells (PGCs) of Xenopus laevis are highly migratory. The last section of their migratory pathway is through the dorsal mesentery of the tadpole gut. This in vivo pathway is rich in fibronectin, a glycoprotein that promotes cell adhesion and migration in vitro. Isolated PGCs are associated with cells from the mesentery and with fibronectin. Treatment with trypsin removes both the mesentery cells and the fibronectin. The PGCs do not appear to resynthesize detectable fibronectin in vitro. In contrast, cultured adult mesentery epithelial cells synthesize large amounts of fibronectin and lay it down in subcellular fibrils that align with intracellular microfilament bundles. PGCs plated on cultured mesentery cell layers adhere to them, elongate and align with the microfilament bundles of the mesentery cells. PGCs adherent to mesentery cell layers are closely associated with fibronectin; moreover, F(ab)2 fragments of anti-Xenopus fibronectin IgG inhibit the adhesion and spreading of PGCs on the mesentery. These results indicate that PGCs can adhere to mesentery cells via fibronectin produced by the latter cells and suggest that fibronectin may be involved in the migration of PGCs in vivo.

Seroepidemiology of malaria: age-specific pattern of Plasmodium falciparum antibody, parasite and spleen rates among children in an endemic area in peninsular Malaysia

A seroepidemiological study was carried out on Orang Asli (Aborigines) children who lead a semi-nomadic life in the deep jungles of Ulu Kelantan, Malaysia. Out of a total of about 190 children below 14 years, 143 were studied. Blood was collected from finger pricks on standard "strip type" filter papers for indirect fluorescent antibody (IFA) tests with Plasmodium falciparum antigen. A positive reaction at 1:10 dilution in infants and young children was considered positive and the reasons are given. The P. falciparum antibody prevalence rate was 84.6% compared to 81.8% spleen and 43.4% parasite rates. Both P. Falciparum and P. vivax were present in children. The age-specific patterns of antibody, spleen and parasite rates were those of a hyperendemic community. There was a positive correlation between antibody and spleen rates up to the age of 9 years. In older children, the antibody rates increased while the spleen and the parasite rates dropped.

Prevalence of antibodies to parasitic infections in Nigerian children

Sixty-six sera from Nigerian children who attended a paediatric clinic at University College Hospital, Ibadan were tested with Plasmodium falciparum, P. brazilianum, Entamoeba histolytica, Toxoplasma gondii and Schistosoma mansoni antigens using indirect fluorescent antibody technique. These sera were tested using ELISA technique for Schistosoma antibodies. Sera from all proven cases of infections gave positive results. Highest antibody prevalence rate was for P. falciparum (69.6%), followed by P. malariae (63.6%) and E. histolytica (42.4%) infections. About 17% and 16% were reactive with Toxoplasma and Schistosoma antigens respectively. Only nine (13.6%) children were negative with all antigens. Forty-four (66.6%) children were positive to two or more parasitic antibodies indicating exposure to those diseases. The significance of these antibodies in children is discussed.

Assessment of the sensitivity, specificity, and reproducibility of the indirect immunofluorescent technique for the diagnosis of amebiasis

The indirect immunofluorescence (IIF) test was used to study antibody titers to Entamoeba histolytica in various manifestations of clinical amebiasis by comparing the results with parasitological and clinical data from confirmed cases. The sensitivity, specificity, and reproducibility of this test for diagnosis were also studied. A high degree of correlation was found between reactivity in the IIF test and confirmed cases of amebic liver abscess. A positivity rate of 96% in sera of confirmed cases of amebic liver abscess in the present study compares favorably with the results of other workers. The IIF test is very useful in the diagnosis of hepatic amebiasis but is less sensitive for amebic dysentery. The test could not be used to differentiate between hepatic amebiasis and amebic dysentery. The IIF test was insensitive for amebic colitis and of no diagnostic value. Specificity and reproducibility of the test were good, as shown by results obtained with sera from patients with parasitic infections other than amebiasis.

Experimental bacterial infection of the biliary tract

The bacterial species commonly found in the human obstructed biliary tract were studied in an animal model of acute hepato-cholangitis. A rank order of their virulence and persistence in the bile and liver was shown which corresponded well to the clinical effects in the animals and also to the prevalence of bile bacteria in the benign bile duct stricture of man. Anaerobic organisms were found to be of low pathogenicity.

Biochemical and electron microscopic studies of the replication and composition of milker's node virus

Replication of milker's node virus (MNV) DNA begins 4 to 8 h postinfection, continues to 30 to 36 h postinfection in the cytoplasm of infected, primary bovine embryonic kidney cells, and is accompanied by an inhibition of host nuclear DNA synthesis. Between 20 and 24 h postinfection, newly replicated genomes are incorporated into particles which cosediment with purified MNV. These biochemical measurements could be correlated with the development of MN virions as revealed by electron microscopic analysis of thin sections prepared from infected cells. Analysis of the DNA in purified MNV showed that the virions contained a double-stranded DNA molecule with a molecular weight of 85 x 10(6) to 87 x 10(6) and a guanine-plus-cytosine content of about 63%. After denaturation and sedimentation analysis of MNV DNA in alkaline sucrose gradients, three major DNA species were resolved. These species appeared to represent intact, terminally cross-linked genomes (approximately 75 to 80S); genomes bearing one nick (or with one cross-link removed) (60 to 65S); and complementary, denatured DNA strands released from cross-linked genomes bearing two nicks (or with both cross-links removed) (52 to 55S). Forty [35S]methionine-labeled polypeptides, ranging from approximately 200,000 daltons to 10,000 to 15,000 daltons, were detected by radioautography after polyacrylamide gel electrophoresis of the proteins present in detergent-solubilized MNV preparations. Treatment of MN virions with Nonidet P-40, beta-mercaptoethanol, and sonication released 10 polypeptides, which were apparently located on the surface of virions. Further fractionation of these released polypeptides, followed by electron microscopy and polyacrylamide gel electrophoresis, indicated that a 42,000- to 45,000-dalton polypeptide is a major component of the threadlike tubule structure present on the surface of MN virions.