Influence of polymer structure on protein partitioning in two-phase aqueous systems

Copolymers of acrylamide and styrene with two distinct structures were synthesized to study the effect of polymer structure on protein partitioning in two-phase aqueous systems. Micellar copolymerization was used to prepare a multiblock copolymer, while homogeneous copolymerization was used to prepare a random copolymer, both with the same composition and molecular weight. Phase behavior studies of the copolymers with poly(ethylene glycol) in water showed little difference in the phase boundaries. However, the partitioning of bovine serum albumin between the two aqueous phases was sensitive to the polymer structure. A molecular picture is proposed for the interactions between the protein and block copolymers. The effect of pH on the protein partition is analyzed in terms of the hydrophobic interactions, and the polymer and protein partitioning was correlated using a model based on the Flory-Huggins theory.

Mediastinal scintigraphy for parathyroid localization in hyperparathyroidism

Two cases are reported demonstrating that mediastinal scintigraphy for hyperparathyroidism should be routinely performed along with scintigraphy of the neck region. Because of the relative cost-benefit ratio, consideration should also be given to performing the procedure before the initial surgery. For the most accurate diagnosis and favorable outcome, our cases suggest that scintigraphic physiologic results should be correlated with anatomic results of conventional radiography.

Oxygen transport proteins: I. Structure and organization of hemocyanin from scorpion (Buthus sindicus)

Scorpions are regarded as the oldest terrestrial arthropods. Scorpion Buthus sindicus (Buthidae) is commonly found in Pakistan and the Mediterranean region. The hemolymph of most arthropods contains large multisubunit, extracellular metalloprotein commonly known as hemocyanin which performs the important function of oxygen transport. The literature available to date shows that no attempt has been made to study hemocyanins or hemolymph proteins from this species. This communication presents the isolation, characterization and partial structural studies on hemocyanin from scorpion Buthus sindicus. (1) The hemolymph was collected by cardiac puncture, centrifuged and subjected to polyacrylamide gel electrophoresis and isoelectric focussing. (2) Crude hemolymph was subjected to gel filtration and high performance ion-exchange chromatography. (3) Purified hemocyanin subunits Bsin 1, 2 and 3 have been analysed for their amino acid composition and N-terminal sequence. The sequence homology was determined by comparison with other arthropod hemocyanin. The results are discussed.

The VEX-test for myocardial scintigraphy with thallium-201 and sestamibi: effect on abdominal background activity

High abdominal background activity of 99mTc-sestamibi may interfere with the diagnosis in studies in which a coronary vasodilator is used; supplemental dynamic exercise might reduce this problem.

METHODS

Clinical and angiographic determinants of subdiaphragmatic-to-myocardial activity ratios were measured on immediate poststress left anterior oblique images and on corresponding tomographic studies 1 hr after injection in 600 sestamibi studies. Similar measurements were made in 550 historic controls with planar 201Tl imaging. Patients performed symptom-limited ergometry when there were no limiting factors, dipyridamole-handgrip in which ergometry was not possible and VEX (vasodilator followed by symptom-limited ergometry) in which exercise capacity was reduced.

RESULTS

Abdominal activity was higher with sestamibi than with 201Tl, in women versus men, and with dipyridamole-based tests compared to exercise alone. Compared to the dipyridamole-handgrip, 3 min of ergometry as part of VEX decreased abdominal background (p < or = 0.02) by 18% on immediate 201Tl images, by 13% on immediate sestamibi images and by 12% on 1-hr delayed sestamibi tomoacquisitions.

CONCLUSIONS

Poststress abdominal background activity is influenced by similar factors with both agents. Supplemental exercise following dipyridamole reduces potentially interfering abdominal activity but perhaps not as efficiently with sestamibi as with 201Tl.

Molecular biointeractions of biomedical polymers with extracellular exudate and inflammatory cells and their effects on the biocompatibility, in vivo

The stability of biomedical polymers in physiological environments is crucial for the normal operation of devices, as well as determining their effect on the tissue response. Degradation is an important factor in polymer biocompatibility, since the environment of the human body can be aggressive to polymers. Most implanted polymers suffer degradation to some extent, and the kinetics and mechanisms of the processes can be affected significantly by various biologically active species, especially enzymes, lipids, peroxides, free radicals and phagocytic cells. The degradation of poly(caprolactone) and poly(DL-lactic acid) under controlled in vivo conditions was studied using a poly(methyl methacrylate) chamber designed to control the exposure of polymers to physiological environments. In particular they may be designed to allow access of extracellular exudate only or access to cells as well as the fluid. The chambers, sealed with filters of pore size either 0.45 micron (impervious to cells) or 3.0 microns (allowing cells to enter the chamber), were implanted subcutaneously into experimental animals for 10, 20 and 30 wk periods. Degradation and molecular interactions of the polymers were characterized by gel permeation chromatography and scanning electron microscopy. The extracellular exudate formed within the implanted chamber is active in promoting the degradation of some biomedical polymers. Inflammatory cells are involved in the biodegradation of implanted polymers by releasing biologically active species such as free radicals into the area surrounding the implant. The data have demonstrated that the hydroxyl radical is likely to be one of the main causes of polymer degradation.

Mechanisms of polymer degradation in implantable devices. 2. Poly(DL-lactic acid)

The hydrolytic degradation of poly(DL-lactic acid) in an aqueous environment in which hydroxyl radicals have been generated has been investigated. Different methods (gel permeation chromatography, differential scanning calorimetry, and scanning electron microscopy) were employed to study the mechanisms of degradation of this amorphous physiologically absorbable polymer. The data indicated that the hydroxyl radical is likely to be a significant factor in the degradation of this polymer.

Mechanisms of polymer degradation in implantable devices. I. Poly(caprolactone)

Poly(caprolactone) is a biodegradable aliphatic (poly(alpha-hydroxy acid), with important applications in the field of human therapy, due to its biocompatibility and bioresorbability. The degradation of poly(alpha-hydroxy acids) depends on chemical hydrolysis, but there is much interest in the precise mechanisms, including the role of free radicals, especially oxygen free radicals and their role in human disease. The hydrolytic degradation of poly(caprolactone) in aqueous environments was used as the control in a study of the effects of hydroxyl radicals in aqueous solutions. Different methods (GPC, DSC, SEM) were employed to investigate the mechanism of degradation of this semicrystalline physiologically absorbable polymer. The data indicate that hydroxyl radical is likely to be a major factor in the degradation of this polymer.

Sexual aggression and love styles: an exploratory study

The relationship between sexual aggression and theoretical love styles was studied. Based on self-reported sexual history, 63 college men were grouped as having either consensual sexual experience only (n = 33) or having verbally coercive sexual experience (n = 30). Analyses were conducted using six love style scales, likelihood to rape, likelihood to use sexual force, masculinity, and sociopathy to predict sexual coercive group membership. Logistic regression indicated that the Ludus love style, a manipulative, game-playing orientation towards intimate relationships, was the best predictor of sexual coercion among the six love styles. Additionally, logistic regression indicated that the Ludus love style was as effective in classifying men as coercive or noncoercive as other dispositions related to sexual aggression. These results suggest that the Ludus love style may serve as a unifying construct for dispositions related to sexual aggression. This study constitutes an initial attempt to link sexually coercive behaviors to a theoretical model of intimate relationships. Results are discussed in the context of a situational model of sexual coercion.

Effect of histaminergic drugs on tail melanophores of tadpole, Bufo melanostictus

The H1 and H2 receptor agonist histamine caused a powerful aggregation of B. melanostictus tail melanophores, which was completely blocked by metiamide, a specific H2 receptor antagonist, while mepyramine an H1 receptor blocker partially blocked the aggregating response. The strong melanin aggregating effect of 4-methyl histamine a specific H2 receptor agonist and its complete blockade by metiamide further supports the conclusion that there exists a dominant population of H2 type of histamine receptors along with sparse population of H1 receptor on the tail melanophores of the toad, which mediate centripetal movement of melanin granules within the pigment cells leading to blanching of the animal.

Topical anesthesia with 50 mg of lidocaine spray facilitates upper gastrointestinal endoscopy

To investigate the value of 50 mg of topical lidocaine spray in upper gastrointestinal endoscopy, a randomized double-blind placebo-controlled study was undertaken with 50 mg of lidocaine spray as the active treatment. All patients were sedated with diazepam after administration of the spray. Included in the study were 158 consecutive patients aged 18 years or older being treated at the endoscopy unit of Scunthorpe district general hospital. Tolerance to upper gastrointestinal endoscopy as assessed by endoscopists and patients was evaluated. Of the 158 patients, 85 received the placebo spray and 73 the lidocaine spray. Patient acceptability for upper gastrointestinal endoscopy was significantly greater in the lidocaine group than in the placebo group (p = 0.001), and tolerance to the procedure as assessed by the endoscopist was also significantly greater in the lidocaine group than in the placebo group (p = 0.008). We conclude that topical anesthesia with 50 mg of lidocaine spray facilitates upper gastrointestinal endoscopy for the endoscopist and increases patient tolerance for the procedure.

Psychiatric morbidity: prevalence, associated factors and significance

A cross-sectional observational systematic study was carried out on ambulatory patients at a tertiary care hospital to determine the probable prevalence, associated factors and significance of psychiatric morbidity by using an Urdu translation of the hospital anxiety and depression (HAD) scale over a period of 6 days in a week. Results showed a prevalence of 38.4% which is slightly higher than what has been generally reported (30%). Two variables, i.e., female sex and being a housewife were significantly related with the outcome. An attempt has been made to identify the probable reasons for this and some suggestions laid down for further work.

The characteristics and performance of dentine bonding agents

Several attempts have been made to synthesise dentine bonding systems, but low bonding strength, increased variance, toxicity and poor hydrolytic stability were some of the disadvantages excluding them from being widely approved. However, many dentine bonding systems are considered to be biocompatible and have become commercially available. These adhesives are thought to have one or two bifunctional agents where one part of the molecule is intended to bond to the inorganic part of the dentine (calcium ions of the apatite), or to the organic part of the dentine (amino and hydroxy groups of the collagen), and the methacrylate part of the molecule is intended to copolymerise with the restorative resin. This review demonstrates that further work is needed to achieve the synthesis of novel dentine bonding agents which bond chemically to dentine by strong covalent bonds, and which are hydrolytically durable and non-toxic to the oral environment.

Onset and regulation of anti-lamin B autoantibody production is independent of the level of polyclonal activation

Anti-lamin B autoantibodies are associated with both systemic lupus erythematosus (SLE) and autoimmune liver disease. We examined the possibility that the underlying clinical feature in patients with anti-lamin B autoantibodies might be chronic autoimmune liver disease, and whether the hypergammaglobulinemia present in both disorders is involved in generating anti-lamin B autoantibodies. A lamin B fusion protein (MLB1), consisting of amino acids 77-533 of lamin B fused to TrpE, was used to screen sera from 84 patients with SLE for anti-lamin B autoantibodies. 3/4 prototype human lamin B antisera, 5/84 SLE sera (6%), and 0/30 sera from healthy individuals reacted with MLB1 on immunoblots at a 1:500 dilution. Of the 9 anti-lamin B autoantibody positive patients studied, all but 1 fulfilled at least four ARA criteria for SLE. None of the patients displayed evidence of chronic autoimmune liver disease, suggesting that autoimmune liver disease is not strongly associated with anti-lamin B antibodies in SLE. In SLE, as in "lupoid hepatitis", anti-lamin B autoantibodies are often produced transiently during periods of increased disease activity. Although polyclonal hypergammaglobulinemia is also associated with increased activity of both diseases, anti-lamin B autoantibody production in 2 patients was independent of total immunoglobulin levels, antibodies to irrelevant proteins, and production of some other autoantibodies. Thus, polyclonal activation is insufficient to explain either the initiation or regulation of anti-lamin B autoantibody production, supporting the hypothesis that antinuclear antibodies are antigen-selective.

Improving the tumor retention of radioiodinated antibody: aryl carbohydrate adducts

Improved methods for attaching radioiodine to monoclonal antibodies have been developed. Ten aryl carbohydrate adducts were synthesized by the reductive amination of a carbohydrate with an aryl amine, using sodium cyanoborohydride as a reducing agent. After purification by chromatography and characterization by nuclear magnetic resonance they were iodinated using the chloramine-T method. Iodinated adducts were activated with cyanuric chloride and incubated with protein at room temperature. The immunoreactivity and avidity of radioiodinated tyramine cellobiose (TCB) labeled antibody were fully preserved when compared to electrophilically radioiodinated antibody. Radioiodinated TCB-and tyramine glucose-labeled monoclonal antibodies showed much greater intracellular retention of radioiodine when compared to electrophilically radioiodinated monoclonal antibodies. Neither radioiodinated tyramine nor radioiodinated TCB had any specific tissue uptake or retention. In mice the retention of radioiodinated TCB labeled anti-Thy-1.1 antibody (1A14) by Thy-1.1-bearing lymphoma cells was 2 times greater than that of chloramine-T labeled 1A14 antibody, whereas the plasma clearance curve and uptake in normal tissues was not changed. This method of radioiodinating monoclonal antibodies increases the retention time of radioiodine in tumor and thus may obviate the problem of intracellular deiodination, a perceived disadvantage of electrophilically iodinated antibodies, with respect to tumor retention of radioactivity.

Preferential use of lambda L chain in lamin B autoantibodies

The generation of lamin B autoantibodies was examined in a patient with SLE. Lamin B autoantibodies in this individual's serum were almost entirely IgG1 lambda at the onset of the autoimmune response. There was no evidence of IgM to IgG class switching, and no apparent diversification of the autoantibody response over the next 2 yr. The kappa/lambda L chain ratio of the lamin B autoantibodies was 0.13 by ELISA, with a kappa/lambda ratio of 0.70 for the patient's total IgG. In contrast, anti-histone autoantibodies in the patient's serum contained primarily kappa L chain. The kappa/lambda L chain ratios of lamin B autoantibodies from sera of four other patients with SLE were also consistent with restricted heterogeneity of lamin autoantibodies. In two, lambda L chain predominated, and in two others, the lamin B autoantibodies contained predominantly kappa L chains. The restricted heterogeneity of lamin B autoantibodies could be related to targeting of a single immunodominant autoepitope, to the existence of a particular L chain gene or genes that preferentially undergo somatic mutation, leading to the production of lamin B reactive clones, or to a combination of both mechanisms.

Preferential use of lambda L chain in lamin B autoantibodies

The generation of lamin B autoantibodies was examined in a patient with SLE. Lamin B autoantibodies in this individual's serum were almost entirely IgG1 lambda at the onset of the autoimmune response. There was no evidence of IgM to IgG class switching, and no apparent diversification of the autoantibody response over the next 2 yr. The kappa/lambda L chain ratio of the lamin B autoantibodies was 0.13 by ELISA, with a kappa/lambda ratio of 0.70 for the patient's total IgG. In contrast, anti-histone autoantibodies in the patient's serum contained primarily kappa L chain. The kappa/lambda L chain ratios of lamin B autoantibodies from sera of four other patients with SLE were also consistent with restricted heterogeneity of lamin autoantibodies. In two, lambda L chain predominated, and in two others, the lamin B autoantibodies contained predominantly kappa L chains. The restricted heterogeneity of lamin B autoantibodies could be related to targeting of a single immunodominant autoepitope, to the existence of a particular L chain gene or genes that preferentially undergo somatic mutation, leading to the production of lamin B reactive clones, or to a combination of both mechanisms.

Bacterial infertility in camels (Camelus dromedarius): isolation of Campylobacter fetus

This study constitutes the first reported isolation of C. fetus subsp. venerealis from cervical swabs in breeding camels. 9 of 30 camels which were barren for a long period were found to be positive for C. fetus. The methods of isolation are described. Additionally, cervical flora of 30 camels were examined. 9 different bacterial species were isolated of which Staphylococcus aureus was most frequently found. All samples were negative for Trichomonas sp. and Streptococcus zooepidemicus.

Peptidic uraemic toxins

A systematic investigation concerning uraemic toxicology has been made using modern analytical methods. The interest is especially focused on substances which are present in uraemic subjects in high concentrations, the so called "uraemic toxins". The samples from biological fluids have been screened with special regards to the presence of peptides and low molecular proteins. These peptidic uraemic toxins are thought to be responsible for certain physiological disturbances when present in uraemic subjects.

[Non-invasive evaluation of cardiac output by Doppler echocardiography]

In order to evaluate Doppler echocardiography (DEC) used for cardiac output (CO) measurement, 22 patients (7 with coronary heart disease, 6 with dilatation cardiomyopathy, 5 with primary pulmonary hypertension and 4 with rheumatic heart disease) were studied. In all patients, invasive CO determination was performed by right heart catheterization, using thermodilution (T). In DEC, CO was calculated as CO = IV.S.HR, where IV was integral velocity, estimated on the basis of flow areas under planimetric curves, S was aortic root cross-section area, and HR was heart rate. A close correlation was demonstrated between DEC and T results (r-0.74). Only in one case with severe aortic atherosclerosis was there a significant difference between the data. This case excluded, the correlation becomes even closer (r-0.86). It is concluded that: 1) DEC is a valuable and precise method of CO assessment, 2) DEC may be used to monitor treatment efficacy, and 3) its limitation is aortic lesions.

Synthesis and radioiodination of tyramine cellobiose for labeling monoclonal antibodies

A tyramine cellobiose (TCB) adduct was synthesized by the reductive amination of cellobiose by tyramine with a product yield of 78%. The TCB adduct was purified by chromatography and then iodinated using the chloramine-T method. After iodination, the adduct was activated with cyanuric chloride and linked to protein by incubation at room temperature for 2 h. Immunoreactivity and avidity were well maintained compared to electrophilically radioiodinated 1A14 whole antibody. The tumor uptake and retention were strikingly greater with iodinated TCB-antibody compared to that of the conventionally iodinated antibody; whereas, the plasma clearance curve and uptake in other organs were not changed. This method of labeling increases the retention time of radioiodine in tumors and thus extends to iodinated antibodies one of the advantages of indium labels, namely that the isotope is not readily washed out of the tumor after it becomes localized.

The skin of the male African catfish, Clarias gariepinus: a source of steroid glucuronides

Steroid metabolism in the skin of mature male African catfish, Clarias gariepinus, reared in the laboratory, was studied in vitro by tissue incubations with [3H]pregnenolone, [3H]dehydroepiandrosterone, [3H]17 alpha-hydroxyprogesterone, [3H]androstenedione, [14C]11 beta-hydroxyandrostenedione, and [3H]testosterone as precursors. While pregnenolone was not converted to any other steroid, dehydroepiandrosterone was transformed mainly to 5-androstene-3 beta, 17 beta-diol. The products of 17 alpha-hydroxyprogesterone incubations were 5 beta-pregnane-3 alpha,17 alpha-diol-20-one, 5 beta-pregnane-3 alpha,17 alpha, 20 beta-triol, and 5 beta-pregnan-17 alpha-o1-3,20-dione. The major steroids of androstenedione incubations were etiocholanolone, testosterone, and androsterone. Testosterone was converted mainly to etiocholanolone and androstenedione, and only small quantities of 11 beta-hydroxytestosterone, 11-ketotestosterone, and 11-ketoandrostenedione were the metabolites found in 11 beta-hydroxyandrostenedione incubation. These results demonstrated the presence of the enzymes 5 alpha- and 5 beta-reductases and 3 alpha-, 11 beta-, 17 beta-, and 20 beta-hydroxysteroid dehydrogenases in the skin. From enzymehistochemical results it appeared that the steroid conversions take place in the epithelial cells. Moreover, the presence of UDP-glucose dehydrogenase, an enzyme involved in the synthesis of glucuronic acid, in these cells indicates the possibility of steroid glucuronide formation. Indeed significant amounts of water-soluble steroid conjugates, particularly 5 beta-dihydrotestosterone- and testosterone-glucuronide, were found in the incubations with androstenedione and testosterone, indicating the presence of the UDP-glucuronosyl transferase in the catfish skin. In the light of these results, a role of the skin of African catfish in the production of semiochemicals having pheromonal properties is discussed.

Hepatic phosphoribosyl pyrophosphate concentration. Regulation by the oxidative pentose phosphate pathway and cellular energy status

Measurements have been made of the tissue content of phosphoribosyl pyrophosphate (PPRibP) and of a range of metabolic intermediates involved in the energy charge of the cell, the glycolytic and pentose phosphate pathways, and of the activity of the enzymes of the pentose phosphate pathway and of PPRibP synthetase (EC 2.7.6.1) in the livers of normal, diabetic, insulin-treated diabetic and starved rats and in livers of rats previously starved and then re-fed with high-fat or high-carbohydrate diets. Diabetes, starvation and high-fat diet all caused a fall in the hepatic PPRibP content, whereas insulin treatment and high-carbohydrate diet raised the tissue content. A positive correlation was shown between the PPRibP content and ATP, energy charge and the cytosolic [NAD+]/[NADH] quotient. A positive association between the PPRibP content and the flux of glucose through the pentose phosphate pathway and the synthesis of ribose 5-phosphate via the oxidative enzymes of that pathway, including ribose-5-phosphate isomerase (EC 5.3.1.6), was also observed. A negative correlation was found between the ADP, AMP and Pi contents, and no correlation existed between PPRibP content and the enzymes of the non-oxidative branch of the pentose phosphate pathway. There was no correlation between hepatic PPRibP content and the activity of PPRibP synthetase measured in vitro. These results are considered in relation to the control of PPRibP synthetase in the liver in vivo.

Characterization of a transplantable adenocarcinoma of the mouse colon producing cachexia in recipient animals

MAC16 is a chemically induced, transplantable adenocarcinoma of the colon passaged in inbred NMRI mice. At small tumor burdens (less than 1% of the host weight), weight loss was observed without a reduction in food intake. As the tumor mass increased, weight loss also increased and reached 33% of host body weight in females and 20% in males when compared with the weight of age-matched controls. The reduction in host body weight was directly proportional to the tumor size and was reversible when the tumor was excised. There was a preferential loss of body fat in tumor-bearing animals with an increase in the plasma level of free fatty acids, although there was a minimal elevation of ketone bodies. Tumor growth was accompanied by progressive hypoglycemia and a reduction in the plasma insulin levels. The decrease in plasma insulin may have contributed to the catabolic effects of progressive tumor growth.

[The inadequacy of indiscriminate periodical radiological examinations in occupational health: results of the 1984 census in a large firm]

São aqui relatados os resultados do censo abreugráfico de 1984 de uma empresa de grande porte, isenta de riscos ocupacionais para o aparelho respiratório. Em 5,308 abreugrafias realizadas foram detectados 53 casos de anormalidades abreugráficas (1%), dos quais apenas 4 de tuberculose ativa. O rendimento foi de 0,75/1,000 abreugrafias. O custo médio de detecção de cada caso de tuberculose ativa foi de 256,32 ORTN (ao redor de 1.850 dólares). Foi também constatado um menor comparecimento de funcionários ao exame abreugráfico periódico, 1,6% de ausências em 1982 e 7,8% em 1984, causado provavelmente pelo crescente conhecimento leigo sobre radiações ionizantes, Os resultados são discutidos e é apresentada uma revisão sobre o emprego de exames radiológicos periódicos em saúde ocupacional.

Blood levels of vanadium, caesium, and other elements in depressive patients

Levels of vanadium and 29 other elements were measured in whole blood of 25 depressive patients, 13 recovered depressive, and 24 control subjects. Vanadium levels were normal in depressive patients, and did not change on recovery. Changes of doubtful significance were found in blood levels of copper, strontium and chromium on recovery from depressive illness. The depressive patients had reduced blood levels of caesium which increased towards normal on recovery. This finding is discussed in relation to pertinent neurochemical and behavioural effects of caesium.

Modulation of human natural killer cytotoxicity by influenza virus and its subunit protein

The influence of intact influenza virus and purified detergent solubilized haemagglutinin (HA) subunits from these viruses on human natural killer (NK) cell activity was examined. Effector cells incubated with whole influenza virus for 18 hr initiated the production of alpha interferon which was associated with the enhancement of NK cell activity. In contrast, purified influenza virus HA suppressed NK activity in a dose-dependent manner, when added at the onset of the cytotoxicity assay, or when used to pre-treated effector cells prior to assay for cytotoxicity against K562 target cells. Effector cells exposed to influenza HA for 90 min, washed and re-incubated in fresh medium for up to 18 hr, failed to regain their cytotoxicity. Suppression of NK cell cytotoxicity could not be ascribed to direct toxicity of HA preparations or residual detergent and preservative in these preparations. The augmented cytotoxicity of activated human effector cells was also susceptible to suppression by virus HA, and pretreatment of human PBL effector cells with HA for 90 min, prior to exposure to human alpha interferon caused NK effector cells to become refractive to the enhancing effects of HIFN. That direct interaction between influenza virus HA and effector cells was a requirement for suppression of activity was shown in experiments using Bromelain-released influenza HA, which would not be expected to bind to cells and which failed to suppress NK cell activity.

Human spleen cells mediating natural killing: altered natural cytotoxicity of spleen effector cells from patients with carcinoma

Spleen cells from eight patients with abdominal carcinoma and six patients undergoing major surgery for a variety of disease entities were assayed for natural cytotoxicity towards 51Cr-labelled K 562 target cells. Patients with abdominal cancer were shown to have relatively weak splenic natural cytotoxicity compared with the reactivity of effector cells from non-carcinoma patients. Nylon wool non-adherent spleen effector cells from cancer patients showed reduced cytolytic capacity compared with effector cells prepared from the spleens of other patients or peripheral blood mononuclear cells (PBMC) obtained from healthy individuals, whereas the splenic reactivity of non-cancer patients showed the same nylon wool separation profile as PBMC, high cytolytic activity being associated with nylon wool non-adherent effector cells. Splenic effector cell cytotoxicity from cancer and non-cancer patients was enhanced following exposure to human interferon, and inhibited by treatment with cholera toxin and simple sugars. Furthermore, fractionation of spleen cells on Percoll discontinuous density gradients demonstrated natural cytotoxic activity to reside predominantly in the low density cell fractions, similar to that found with NK cells from peripheral blood. Thus the properties described here for human cytotoxic spleen cells are similar to those described for peripheral blood NK cells, suggesting these two effector cell populations to be closely related, if not identical.

Kinetics of red cell membrane phosphorylation: altered affinity of HS membrane protein acceptors

Membrane ghosts were prepared from red blood cells of normal and hereditary spherocytosis (HS) subjects. Time dependent phosphorylation studies of the membrane (in the presence of gamma labelled AT32P) showed that the HS membrane appeared to incorporate less phosphate than the normal membrane but the results were not significantly different. Using the initial linear rate of phosphorylation and varying the ATP concentration, it was found that the Michaelis constant (Km) for the normal membrane was 24.8 microns ATP and Vmax was 0.120 nmol phosphate bound/mg membrane protein/min. These values for the HS membrane were found to be 39.0 and 0.118 respectively. In one family the affected mother and son each showed a positive cooperativity effect for similar reciprocal plots. This indicates that phosphorylation of various HS membrane proteins may be an ordered rather than random process and suggests biochemical heterogencity of the HS condition. The constants, Km and Vmax, however, were found to be similar to the rest of HS subjects studied. Crude extracts of the enzyme protein kinase, which catalyses the membrane phosphorylation, showed no significant difference in the Km and Vmax value in HS compared with that from normal red cells. The kinetic difference in phosphorylation is probably due to abnormalities in the membrane protein(s) which accept the phosphate from protein kinase in HS red cells.

Isolation of Bacillus thuringiensis for microbiological control of insects

Eleven of 180 local isolates, belonging to Bacillus thuringiensis, were tested for their pathogenicity to pinkbollworm larvae (Pectinophora gossypiella). Three strains, namely RS-25, RS-35, and RS-45, showed a positive insecticidal activity. Their activities based on the crystalline inclusion bodies. The LD50 (hours) for larvae was 8, 12, and 6 hours, respectively.

An improved method for the extraction of cholesterol and phospholipids from the bovine spinal cord

A pharmacopoeial grade of cholesterol and a separate phospholipid fraction can be obtained by this simple extraction procedure of bovine spinal cord. The tissue is collected in 5% (Wt/V) formalin. It is then separated from the formalin solution, minced and dried in a hot-air oven at 105 degrees C. Total lipids are extracted with petroleum ether. The cholesterol is separated from the phospholipids by extraction with a mixture of petroleum ether and acetone. The method allows for not only the recovery of the phospholipids but also a high yield of cholesterol without using saponification or tedious purification procedures.

Utilization of agricultural wastes of Aspergillus awamori for the production of glucoamylase

The principal industrial use of glucoamylase is in the production of crystalline D-glucose. Aspergillus awamori was used. Variations in the specific type of carbohydrate source affected the yield of enzyme markedly. Of all the substrates tried, maltose supported satisfactory enzyme yields. Sucrose, lactose, fructose, and galactose gave abundant growth which seemed to be necessary but no sufficient condition for maximum yields. The specificity of the carbohydrate structure for gluco-amylase production was tried. The synthesis of enzyme was significantly stimulated when two-third of the starch in the medium was replaced by maltose. The adaptation seemed to be specific to maltose structure, since the substitution of maltose by structurally related compounds, a.o. lactose, in the medium did not give a comparable glucoamylase yield. Maltose or compounds composed of maltose gave maximum yields of enzyme. These results seemed to favour the theory that glucoamylase production is adaptive. Agricultural wastes produced locally in large quantities from plants manufacturing starch and other products were discussed. Rice bran, followed by glucose syrup, corn bran, wheat bran, and can sugar molasses supported good yields of glucoamylase.

Red Sea Drillings

Recent drilling in the Red Sea has shown that much of the basin is underlain by evaporites of a similar age to that of evaporites found in the Mediterranean Sea. These evaporites and their structural positions indicate that other brine areas are present-and, indeed, several others have been discovered.

Pernicious anaemia among Arabs in Kuwait

Addisonian pernicious anaemia is believed to be very rare in Arabs. Three cases are reported. Two were Jordanians of Palestinian origin and one an Egyptian. All had the typical peripheral macrocytosis, a frankly megaloblastic bone marrow, and a Schilling test result in the range of pernicious anaemia. All three improved remarkably on vitamin B(12) therapy and have maintained a normal haemoglobin level. There was no evidence of gastric carcinoma in any of these cases.

Haemoglobin H disease in Arabs in Kuwait

Three cases of haemoglobin H disease are described in Arabs, two of Syrian and one of Kuwaiti origin. Two were investigated on account of moderate anaemia, the third for splenomegaly not associated with anaemia.