Analysis of the colonization of unirradiated and irradiated SCID mice by human lymphoma and non-malignant lymphoid cells

We have evaluated the severe combined immunodeficient (SCID) mouse as an in-vivo model for the study of non-Hodgkin's lymphomas (NHL). Characterization of the immune system of the animals in our SCID mouse colony was carried out to assess the numbers of lymphoid cells present, to determine natural killer (NK) cell activity as a function of age and to examine the histology of the lymphoid organs. In this study four human NHL established cell lines (Daudi, Namalwa, U937, MC116), lymphoma cells from four fresh NHL biopsies and normal peripheral blood mononuclear cells (PBMC) and bone marrow cells were investigated, after intraperitoneal injection into the mice. The presence of the human NHL cells in the peritoneum and spleen was assessed by FACS analysis. The colonization potential was investigated in a range of tissues by polymerase chain reaction (PCR) amplification of human repetitive sequences. These studies revealed clear differences in the abilities of the NHL cell types to colonize the SCID mice. Namalwa, Daudi and U937 cells demonstrated the highest efficiency of colonization and readily formed tumours, whereas MC116, the NHL biopsy cell populations and the non-malignant lymphoid cells showed little ability to survive and colonize other tissues in the SCID mice. Whole body irradiation of the SCID mice appeared to improve the survival of human PBMC, NHL biopsy cells and MC116 cells in the peritoneum, but had little effect on their colonization potential. The significance of these studies is discussed.

Pediatric gastric emptying: value of right lateral and upright positioning

Gastroesophageal reflux and gastric emptying are usually assessed simultaneously with a 1-hr procedure. After ingestion of radiolabeled formula sequential images are gathered when the infant is in the supine position. This position is adequate for gastroesophageal reflux assessment, but delays gastric emptying.

METHODS

We studied 48 children, 1 wk to 2 yr of age, who presented with vomiting or failure to thrive. They received 99mTc-sulphur colloid in formula. After completing 1 hr supine imaging we obtained additional abdominal views after changing the position of the infant to right lateral for 30 min, and upright for another 30 min.

RESULTS

The percent of gastric emptying at 60 min in the supine position was 35% +/- 19%. After 90 min, in the right lateral decubitus, the percent gastric emptying was 60% +/- 25%. At 120 min, after an upright period, the gastric emptying was 73% +/- 20%. In the supine position 19 of 48 patients showed significant emptying (defined as > 40% emptying). This increased to 41 of 48 normal studies considering the right lateral position and to 45 of 48 normal studies considering the infant upright position.

CONCLUSION

Many patients with delayed gastric emptying show significant emptying just by changing position. We routinely complement gastric emptying studies with delayed views in the right lateral and upright position.

Mammoscintigraphy with technetium-99m-sestamibi in suspected breast cancer

Our goal was to determine the clinical usefulness of 99mTc-sestamibi to identify breast cancer in patients prior to biopsy.

METHODS

We studied 66 patients who received 20 mCi 99mTc-sestamibi intravenously. Lateral and anterior planar images were gathered within 30 min of the injection. Only focal increased uptake was interpreted as positive. Confirmatory pathologic diagnoses were obtained within 2 mo. The prevalence of breast cancer in our sample was 54%.

RESULTS

We report an overall sensitivity of 83% and specificity of 93% for the diagnosis of breast cancer. In palpable lesions, the sensitivity was of 94% with a specificity of 91%, while in nonpalpable abnormalities the sensitivity was of 64% with a 100% specificity. Six patients with a malignancy had negative scans, four of these lesions were nonpalpable. Only two of 31 patients with benign lesions had an abnormal scan.

CONCLUSION

Mammoscintigraphy with 99mTc-sestamibi has high specificity and adequate sensitivity for the noninvasive diagnosis of breast carcinomas.

Effect of histaminergic drugs on integumental melanophores of adult Bufo melanostictus

Histamine and 2-methyl histamine caused dose-dependent aggregation of melanophores in toad B. melanostictus. The effects were effectively antagonised by mepyramine, a specific H1 histamine receptor antagonist, and metiamide a specific H2 receptor antagonist. On the other, hand 4-methyl histamine, a specific H2 receptor agonist dispersed the melanophores. The results suggest that adult Bufo melanophores have H1 histamine receptors which mediate melanophore aggregation, however, dispersion of melanophores may be controlled by undifferentiated histamine receptors of H2 type.

Clinical-epidemiologic study of alopecia areata

BACKGROUND

Alopecia areata is a common disease and may be associated with autoimmune disease, atopy, Down syndrome, emotional stress, and foci of sepsis.

METHODS

Seven cases of alopecia areata were diagnosed among workers in the Water and Effluent Treatment Sector (WETS) of a paper factory, representing a 0.6% incidence, when the value for the population at large is 0.1%. Three of these workers are assigned to the WETS on a permanent basis and four provide maintenance services. One of the latter patients had alopecia areata that fully regressed. Because biologic treatment of water and effluents involves saprophytic bacteria and fungi as well as chemical substances such as acrylamide, a clinical examination and laboratory tests were performed on all workers assigned permanently to the WETS (N = 9) and on 25% of the workers, selected at random providing services to the sector (N = 14).

RESULTS

There was no association between alopecia areata and atopy, dermatophytosis, or bacteria isolated. Toxicologic evaluation revealed an acrylamide-like substance in 7 workers with alopecia areata, with a statistically significant correlation. Measures were taken at the workplace to decrease worker contact with the mists (probably containing acrylamide) in the pulp-pressing room; no other cases of alopecia areata had been detected 1 year after the study.

CONCLUSIONS

A survey of the literature did not show reports of alopecia areata as an occupational dermatosis, but our conclusion is, that this dermatosis could be due to the professional activities of the workers at the paper factory studied.

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.