Pharmacokinetics and biodistribution of genetically-engineered antibodies

Monoclonal antibodies (MAbs), because of their inherent specificity, are ideal targeting agents. They can be used to deliver radionuclides, toxins or cytotoxic drugs to a specific tissue or malignant cell populations. Intact immunoglobulin (IgG) molecules have several practical limitations of their pharmacology; their relatively large size of approximately 150,000 daltons leads to a slow clearance from the blood pool and the body resulting in significant exposure to normal organs with limited quantities delivered to tumors. The IgG molecule shows a relatively poor diffusion from the vasculature into and through the tumor. Attempts to modify the pharmacology of the Ig molecule have classically involved the use of proteases to generate F(ab')2 and Fab' fragments with molecular weights of approximately 100,000 and 50,000 daltons, respectively. Fv fragments of IgG are one of the smallest size functional modules of antibodies that retain high affinity binding of an antigen. Their smaller size, approximately 25,000 daltons, enables better tumor penetration and makes them potentially more useful than a whole antibody molecule for clinical applications. Molecular cloning and expression of the variable region genes of IgG has greatly facilitated the generation of engineered antibodies. A single-chain Fv (scFv) recombinant protein, prepared by connecting genes encoding for heavy-chain and light-chain variable regions at the DNA level by an appropriate oligonucleotide linker, clears from the blood at much faster rate than intact IgG. The scFv fragment can retain an antigen-binding affinity similar to that of a monovalent Fab' fragment; this however, represents a relative decrease in binding affinity when compared to intact antibodies. The scFv with its faster clearance and lower affinity results in a lower percent-injected dose localizing in tumors when compared to the divalent IgG molecule. This may be adequate for imaging but probably not for therapy. The valency of the MAb fragment is critical for the functional affinity of an antibody to a cell surface or a polymeric antigen. In attempts to generate multivalent forms of scFv molecules, non-covalently linked scFv dimeric and trimeric molecules, disulfide linked dimeric scFvs, as well as covalently linked chimeric scFvs have been studied. These multivalent scFvs generally have a higher functional affinity than the monovalent form resulting in better in vivo targeting. Another way to alter the pharmacology of the scFvs is to modify its net charge. Charge-modified scFvs with desired isoelectric points (pI), have been prepared by inserting negatively charged amino acids on the template of the variable region genes. This can help to overcome undesirable elevations in renal uptake seen with most antibody fragments. In conclusion, genetic manipulations of the immunoglobulin molecules are effective means of altering stability, functional affinity, pharmacokinetics, and biodistribution of the antibodies required for the generation of the "magic bullet".

Coordination of an array of signaling proteins through homo- and heteromeric interactions between PDZ domains and target proteins

The rapid activation and feedback regulation of many G protein signaling cascades raises the possibility that the critical signaling proteins may be tightly coupled. Previous studies show that the PDZ domain containing protein INAD, which functions in Drosophila vision, coordinates a signaling complex by binding directly to the light-sensitive ion channel, TRP, and to phospholipase C (PLC). The INAD signaling complex also includes rhodopsin, protein kinase C (PKC), and calmodulin, though it is not known whether these proteins bind to INAD. In the current work, we show that rhodopsin, calmodulin, and PKC associate with the signaling complex by direct binding to INAD. We also found that a second ion channel, TRPL, bound to INAD. Thus, most of the proteins involved directly in phototransduction appear to bind to INAD. Furthermore, we found that INAD formed homopolymers and the homomultimerization occurred through two PDZ domains. Thus, we propose that the INAD supramolecular complex is a higher order signaling web consisting of an extended network of INAD molecules through which a G protein-coupled cascade is tethered.

Human leukemia-derived dendritic cells: ex-vivo development of specific antileukemic cytotoxicity

The human myeloid leukemias are a diverse group of disorders characterized by massive clonal expansion of myeloid cells showing variable degrees of differentiation block. Leukemic dendritic cells were generated in culture from chronic myelogenous leukemia (CML). These were used to stimulate autologous T cells to develop leukemia-specific cytotoxicity. Available data suggest that the cells responsible for the cytolytic activity are at least in part CD8+ and HLA restricted in their function. Additional data suggest that some anti-CML cellular activity may be Fas mediated. T-cell receptor studies provide evidence for an oligoclonal response implying a recognition of a limited number of antigens. We have used culture techniques similar to those used for CML to study the ability of AML cells to differentiate toward dendritic cells. Four of five patients have shown acute leukemia-derived dendritic cells. This work offers an avenue for the development of novel strategies for the control of human myeloid leukemias.

Crepidostomum percopsisi n. sp. (Digenea: Allocreadiidae) from the trout perch (Percopsis omiscomaycus) of Dauphin Lake, Canada

Crepidostomum percopsisi n. sp. is described from the small intestine of the trout perch (Percopsis omiscomaycus) in Dauphin Lake, Manitoba. It is morphologically similar to Crepidostomum isostomum, which has been reported from the trout perch and several other species of fish. It differs from C. isostomum based on the vitellaria confined to the hindbody of the worm, size and shape of the cirrus, size of the testes, and its greater body length. A comparison of our specimens with those illustrated and identified as C. isostomum from trout perch indicates that such specimens are identical to larger specimens of C. percopsisi recovered by us from trout perch in May. To date, C. percopsisi has only been reported from the trout perch of Dauphin Lake, Lake Winnipeg, and Oneida Lake, which suggests host specificity.

Recognition of the parasite infected cell surface determinants by homologous antiserum raised against infected cell membranes

Identification of neo-antigenic determinant(s) on parasite infected cell surface is important to control intracellular infections. Such determinant(s) on the surface of intact Plasmodium berghei infected erythrocytes have not been conclusively demonstrated. To generate polyclonal antiserum selectively recognizing the parasite infected cell surface determinant(s), in natural state, we have examined the efficacy of the homologous immunizations, in BALB/c mice, with the membrane rich preparation of: i) erythrocytes in vivo infected with Plasmodium berghei and, ii) macrophages in vitro infected with Leishmania donovani. Anti-infected erythrocyte membrane antiserum specifically recognized, albeit at low level, the infected cell surface as determined by flow cytometry and immunoelectron microscopy. Immunoprecipitation of radiolabeled antigens revealed at least three parasite proteins of > 205 kDa, 160 kDa and 100 kDa specifically present on infected erythrocyte surface. Normal uninfected erythrocytes did not react with the antiserum. Anti-L. donovani-infected macrophage membrane antiserum also recognized only infected macrophage surface and not the normal macrophages. Thus, the approach may find wide application in delineating disease specific determinant(s) on the infected cell surface, particularly to those where animal models are available.

Disruption of T cell tolerance by directing a self antigen to macrophage-specific scavenger receptors

Breakdown of immune self tolerance is speculated to cause autoimmune diseases, but most studies on tolerance use foreign molecules as targets. In this study, we show another approach using delivery of a maleylated self protein to macrophage-specific scavenger receptors. Mice generate Abs against the maleylated form of a ubiquitous self Ag, mouse serum albumin (MSA), although native MSA is nonimmunogenic. This generation of anti-maleyl MSA Abs depends on binding of maleyl MSA to scavenger receptors in vivo, since coinjection of a serologically unrelated scavenger receptor ligand inhibits it, suggesting that the Ab response is T cell dependent. Spleen cells as well as nylon adherence-purified splenic T cells from maleyl MSA-immune mice proliferate in response to both maleyl MSA and MSA; this response is blocked by anti-MHC class II mAbs, and the autoimmune cells can recognize at least five 15-mer peptides from the MSA sequence, establishing that T cell tolerance to MSA has been broken in these mice. Maleyl MSA and MSA are recognized equally well, provided the scavenger receptor-specific delivery of maleyl MSA is blocked during stimulation in vitro, indicating that maleyl MSA-specific non-self peptides are unlikely to play a major role in the observed disruption of T cell tolerance. Thus, delivery of some self molecules to scavenger receptors may lead to disruption of immune tolerance. These results are relevant to mechanisms of immune tolerance and the etiopathogenesis of autoimmunity.

Disruption of T cell tolerance by directing a self antigen to macrophage-specific scavenger receptors

Breakdown of immune self tolerance is speculated to cause autoimmune diseases, but most studies on tolerance use foreign molecules as targets. In this study, we show another approach using delivery of a maleylated self protein to macrophage-specific scavenger receptors. Mice generate Abs against the maleylated form of a ubiquitous self Ag, mouse serum albumin (MSA), although native MSA is nonimmunogenic. This generation of anti-maleyl MSA Abs depends on binding of maleyl MSA to scavenger receptors in vivo, since coinjection of a serologically unrelated scavenger receptor ligand inhibits it, suggesting that the Ab response is T cell dependent. Spleen cells as well as nylon adherence-purified splenic T cells from maleyl MSA-immune mice proliferate in response to both maleyl MSA and MSA; this response is blocked by anti-MHC class II mAbs, and the autoimmune cells can recognize at least five 15-mer peptides from the MSA sequence, establishing that T cell tolerance to MSA has been broken in these mice. Maleyl MSA and MSA are recognized equally well, provided the scavenger receptor-specific delivery of maleyl MSA is blocked during stimulation in vitro, indicating that maleyl MSA-specific non-self peptides are unlikely to play a major role in the observed disruption of T cell tolerance. Thus, delivery of some self molecules to scavenger receptors may lead to disruption of immune tolerance. These results are relevant to mechanisms of immune tolerance and the etiopathogenesis of autoimmunity.

Use of leukemic dendritic cells for the generation of antileukemic cellular cytotoxicity against Philadelphia chromosome-positive chronic myelogenous leukemia

The success of adoptive immunotherapy for the treatment of leukemia depends on the generation of T cells that can specifically react with malignant cells. Dendritic cells (DCs) are important antigen-presenting cells in the development of antileukemic T-cell responses. In this study, we generated DCs from peripheral blood cells of patients with chronic myelogenous leukemia (CML). CML cells incubated concurrently with granulocyte-macrophage colony-stimulating factor, interleukin-4, and tumor necrosis factor-alpha in vitro developed morphologic and phenotypic characteristics of DCs. Fluorescence in situ hybridization showed the presence of t(9;22) in the nuclei of these cells, indicating that they were leukemic in origin. These cells were potent stimulators of lymphocyte proliferation in specific in vitro assays for DC function. Autologous T cells stimulated with in vitro-generated, leukemic DCs displayed vigorous cytotoxic activity against CML cells but low reactivity to major histocompatability complex-matched normal bone marrow cells. Cytotoxic activity against CML targets was fourfold to sixfold higher using DC-stimulated autologous T cells than with autologous T cells expanded by culture with interleukin-2 alone. DC-stimulated T cells also inhibited growth of CML clonogenic precursors in colony-forming assays in vitro. These results suggest that cytokine-driven in vitro differentiation of CML cells results in generation of DCs with potent T-cell stimulatory function. In vitro-generated DCs can be effectively used as antigen-presenting cells for the ex vivo expansion of antileukemic T cells.

Diclybothrium atriatum n. sp. (Monogenea:Diclybothriidae) from North American acipenserid fishes with observations on Diclybothrium armatum and Diclybothrium hamulatum

Diclybothrium atriatum n. sp. is described from North American acipenserid fishes, Acipenser fulvescens Rafinesque (lake sturgeon) and Acipenser brevirostrum Le Sueur (shortnose sturgeon). Diclybothrium atriatum is distinguished from other diclybothriids by the presence of a unique preovarial structure that we name the ventral atrial organ. This structure possesses a ventral orifice leading to a deep groove that widens internally as a crypt, bordered by densely staining granular bodies and more deeply situated glandular cells. Previous records of Diclybothrium armatum Leuckart, 1835 examined in this study from North American acipenserids are referable to D. atriatum. Studies on the anatomy of this and other species of Diclybothrium Leuckart, 1835, D. armatum and Diclybothrium hamulatum (Simer, 1929), reveal the presence of paired multichanelled sperm ducts that are shown to be characteristic of the Diclybothriidae Bykhovskii and Gusev, 1950. Paired sperm ducts, while common in Turbellaria with multiple testes, are unusual amongst Monogenea. The endemicity of Diclybothrium atriatum and specificity for A. fulvescens and A. brevirostrum suggests that speciation of this parasite may have occurred following the isolation of Acipenser L. spp. in central and eastern North America.

Observations on the morphology, systematics, and biogeography of the genus Truttaedacnitis (Nematoda:Cucullanidae)

All species of Truttaedacnitis Petter, 1974, were examined for a phylogenetic analysis. Morphological studies showed that Truttaedacnitis truttae (Fabricius, 1794) from North America possessed a reduced button-shaped or nipple-shaped caudal mucron that is in contrast to the sharp spike-shaped mucron commonly reported in Eurasian specimens. Histological studies showed that the excretory pore in Truttaedacnitis sphaerocephala (Rudolphi, 1809) was situated near the level of the pseudobuccal capsule between the 2 parts of the ventral cephalic ridge. Cucullanus heterodonti Johnston and Mawson, 1943 is transferred to Truttaedacnitis based on the presence of prominent cephalic plates separated by sutures. An hypothesis regarding interrelationships among Truttaedacnitis spp. was developed using phylogenetic systematics. The anterior excretory pore is a synapomorphy supporting the monophyly of Truttaedacnitis clitellarius (Ward and Magath, 1917) and T. sphaerocephala parasitizing sturgeons. The arrangement of cephalic plates indicates that Truttaedacnitis pybusae Anderson, 1992 and T. truttae may form a monophyletic group and further supports the monophyly of T. clitellarius and T. sphaerocephala. Using unordered character states of different cephalic plates produced a cladogram that suggested that species in holarctic/circumboreal families (Acipenseridae, Salmonidae, Petromyzontidae) may be monophyletic. The systematics and biogeography of the various species of Truttaedacnitis and their host specificity indicate that associations in this parasite genus are very ancient and of a relictual nature, determined largely by past continental and oceanic configurations, and a combination of vicariance and dispersal.

Character of a wheat amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and hormones

BACKGROUND & AIMS

Amylase inhibition induces carbohydrate tolerance, satiety, and weight loss and prolongs gastric emptying, effects that may be useful in the treatment of obesity and non-insulin-dependent diabetes mellitus. The aim of this study was to determine (1) purity of a wheat amylase inhibitor preparation, (2) intraduodenal concentration of the wheat amylase inhibitor preparation that inhibits > 90% amylase activity (which causes carbohydrate malabsorption), and (3) if the inhibitor alters pancreaticobiliary secretions or intraluminal pH.

METHODS

High-performance liquid chromatography followed by electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used for characterization. Groups of 3 subjects received intraduodenal infusions of 3.0, 4.5, or 6.0 mg/mL of the inhibitor for 90 minutes during the middle of a 270-minute essential amino acid solution infusion (which stimulates 50% maximal pancreatic enzyme secretion). Pancreatic enzyme and bile acid delivery to the duodenum were measured for a 270-minute period.

RESULTS

The inhibitor is 96% protein, 59% containing 0.19, 0.28, 0.38, and 0.53 inhibitors. The 0.38 inhibitor has the most antipancreatic alpha-amylase activity. The inhibitor reduced amylase activity in the duodenum dose dependently (r = 0.7; P = 0.04); > 4 mg/mL inhibited > 90% amylase activity but did not affect delivery of other enzymes or bile acids to the duodenum or gastric or duodenal pH.

CONCLUSIONS

The preparation has a high protein purity and a high specific activity against alpha-amylase activity and effectively inhibits human pancreatic amylase activity secreted into the duodenum.

Lipid and fatty acid composition of muga silkworm, Antheraea assama, host plants in relation to silkworm growth

The lipid and fatty acid composition of the leaves (tender, medium and mature) of muga host plants, Machilus bombycina, Litsaea monopetala (primary food plants) and L. cubeba and L. salicifolia (family: Lauraceae) (secondary food plants) was investigated by standard procedures, gas chromatography after saponification and esterification. The total lipid content of M. bombycina and L. monopetala leaves was recorded to be higher (16 and 18 g%), respectively, than that of L. cubeba (10 g%) and L. salicifolia (12 g%). GC analysis identified the presence of eight fatty acids (C14 to C22) and the concentration varied from 0.0297 to 8.1572 g% dry leaf powder. Among the fatty acids, (C14 to C22), polyunsaturated fatty acids were recorded to be highest in concentration in mature leaves of the primary host plants. The concentrations of saturated and polyunsatuated fatty acids were found to be at a minimum level in all the types of leaves of secondary muga host plants.

Function and cell surface phenotype of dendritic cells from rat cornea

PURPOSE

To isolate dendritic cells (DC) from rat corneas and to examine their functions and surface markers in vitro.

METHODS

Cells were isolated enzymatically from dissected rat corneas and cultured for various intervals of time. Dendritic cells were enriched immunomagnetically from corneal cell preparations using monoclonal antibodies against DC surface antigens and tested for functional activity in lymphocyte stimulation assays. In vivo migration of DC was induced by traumatizing the corneal epithelium. Wholemounts of epithelial sheets were stained immunofluorescently with anti-DC antibodies and examined by confocal microscopy. Dendritic cells isolated from traumatized corneas were tested for functional activity.

RESULTS

Corneal DC exhibited the properties of other members of the DC family, i.e., low buoyant density, lymphoid DC-specific markers, and lymphostimulatory function. In fresh unfractionated cell preparations of normal cornea, no functional activity was detected. However, DC immunomagnetically purified from fresh preparations were functionally active. Injury to the corneal epithelium induced the migration of DC from the periphery to the central cornea; DC measured in this situation showed significantly increased functional activity. Finally, IL-1 beta and GM-CSF enhanced the functional activity of corneal DC.

CONCLUSIONS

Corneal DC have lymphostimulatory capacity in situ, but they may be maintained in a state of latency by the suppressive influence exerted by neighboring cells. Injury to the corneal epithelium results in functional activation of the corneal DC, which may be caused by cytokines such as IL-1 beta or GM-CSF. Thus, corneal DC may be important in the immune regulation of the anterior segment.

Chloroquine encapsulated in malaria-infected erythrocyte-specific antibody-bearing liposomes effectively controls chloroquine-resistant Plasmodium berghei infections in mice

The suitability of liposomes as drug carriers in the treatment of drug-resistant rodent malaria was examined after covalently attaching F(ab')2 fragments of a mouse monoclonal antibody (MAb), MAb F10, raised against the host cell membranes isolated from the Plasmodium berghei-infected mouse erythrocytes, to the liposome surface. The antibody-bearing liposomes thus formed specifically recognized the P. berghei-infected mouse erythrocytes under both in vitro and in vivo conditions. No such specific binding of the liposomes with the infected cells was observed when MAb F10 was replaced by another mouse monoclonal antibody, MAb D2. Upon loading with the antimalarial drug chloroquine, the MAb F10-bearing liposomes effectively controlled not only the chloroquine-susceptible but also the chloroquine-resistant P. berghei infections in mice. The chloroquine delivered in these liposomes intravenously at a dosage of 5 mg/kg of body weight per day on days 4 and 6 postinfection completely cured the animals (75 to 90%) of chloroquine-resistant P. berghei infections. These results indicate that selective homing of chloroquine to malaria-infected erythrocytes may help to cure the chloroquine-resistant malarial infections with low doses of chloroquine.

Epidemiological studies of blood groups in the district of Bankura with special reference to tribals

Distribution of ABO blood groups was studied in 4301 subjects, both tribals and non-tribals of the district of Bankura in West Bengal. It was observed that group 'O' blood was found in most cases and group 'AB' was seen in least number of cases. It was also found that there was no significant difference in distribution of blood groups between the tribals and non-tribals.

Characterization and functional activity of dendritic cells from rat choroid

Cell preparations from the posterior eye cup of the eye cultured for 2 days exhibited accessory activity for T-cell responses to a mitogenic treatment and stimulatory activity in a mixed leukocyte reaction (MLR), two functions characteristic of dendritic cells (DC). These activities both partitioned with cells having a low buoyant density, another characteristic of DC. Immunomagnetic separations with monoclonal antibodies against lymphoid dendritic cell surface antigens revealed that the accessory activity of the low-density cells was entirely associated with a small population of cells positively selected by these antibodies. Immunofluorescent staining with these same antibodies also revealed a small subpopulation of low-density cells having the morphology of DC. On cryostat sections of eye tissue the positively-stained cells were localized in the choroid and were not observed within the sclera or the retina. Based on these results we conclude that there are functional DC in the choroid, and we speculate that they may have a significant role in the inflammatory process during posterior uveitis.

Purification and partial characterization of a heparin-binding lectin from the marine clam Anadara granosa

The heparin-binding lectin, Anadarin MS, from the plasma of the marine clam Anadara granosa is purified through affinity chromatography on heparin-Sepharose 4B followed by gel filtration on a Sepharose 6B column. The purified lectin is a pentameric protein of native M(r) 300 kDa and is composed of identical subunits of 60 kDa. The pI value of this Ca(2+)-dependent lectin is 6.2. Anadarin MS agglutinates normal rabbit erythrocytes but not that of human. Aspartic acid, glutamic acid, histidine and glycine are the predominant amino acids. Unlike other reported heparin-binding lectins, Anadarin MS exhibits a unique and strict specificity for iduronic acid containing glycosaminoglycans. This lectin agglutinates infective promastigotes of Leishmania donovani exclusively and can therefore be used as a novel biochemical surface marker for this parasite.

Purification and partial characterization of a N-glycolylneuraminic acid specific lectin from the clam Anadara granosa (L)

The N-glycolylneuraminic acid-specific lectin (AFL) from the foot muscles of the marine clam Anadara granosa has been purified to homogeneity by affinity chromatography on bovine submaxillary mucin-Sepharose 4B. The Ca(2+)-dependent lectin agglutinates rabbit erythrocytes. The purified lectin is a tetrameric protein of native M(r) 254 kDa having a pI value of 6.65. The M(r) of two subunits is 65 kDa each and that of the remaining two is 62 kDa each. The dominant amino acids of the lectin are aspartic acid, glutamic acid, serine and glycine. The lectin activity is inhibited only by N-glycolylneuraminic acid specially when it is present in the macromolecular structure of mucin viz., porcine submaxillary mucin, which is the most potent inhibitor. The binding site does not recognize N-acetylneuraminic acid. Due to this strict specificity, the lectin appears to be unique.

A novel galactosyl-binding lectin from the plasma of the blood clam, Anadara granosa (L) and a study of its combining site

The marine blood clam species Anadara granosa (L) belong to arcidae, a family with some extraordinary haematological features. The plasma of this species exhibited strong haemagglutinating activities, from which a galactosyl binding lectin, Anadarin P, was purified in a single step affinity chromatography using Sepharose 4B-asialofetuin as an affinity matrix. The purified lectin, eluted with lactose, was found to be homogeneous by alkaline polyacrylamide disc gels, gel-filtration and isoelectric focusing. Native M(r) of the lectin was 130,000 having a PI value of 6.82 and was composed of two subunits of M(r) 17,000 and M(r) 16,000 which were noncovalently bound. The lectin was remarkably thermostable; the agglutinating titre remained unchanged over a wide range of pH (from 5 to 10) but increased with neuraminidase treated rabbit erythrocytes. Anadarin P combining site has been proposed to be small pocket-like structure which recognised only C-3 and C-4 hydroxyl groups of D-galactose. Presence of bulky groups at C-2 and C-6 exert strong steric hindrance as L-arabinose, 2-deoxy-D-galactose and D-xylose are better inhibitors than D-galactose. The lectin fails to differentiate methyl substituted galactosides as both alpha- and beta- methyl galactosides are equally active; but in case of substituted phenyl glycosides, the lectin shows different affinity towards alpha and beta anomers. The avidity of the lectin to bind the aromatic aglycons of galactosides suggests the presence of a hydrophobic region in the combining site. Interactions with some disaccharides indicate the presence of an extended area near the monosaccharide binding site.

A search for immunocontraceptive agent from marine sources--role of antispermatheca globulin of Telescopium telescopium on fertility regulation in male rat

Polyclonal antisera were developed in rabbits against 'spermatheca', the reproductive gland of T. telescopium, a marine mollusc. The gland contains spermatozoa. Antisera and its IgG fraction (ASTG) indicated common antigenic determinants by immunodiffusion and had titer values 81920 and 1280 against crude antigen extract. Cycling female rats when exposed to passively immunized male rats with different doses of ASTG, had reduction in implantation sites and litter size. Females had pseudopregnancy when exposed to higher doses of immunized males and had normal cycle after 20 days in average. ASTG in male rats caused decrease in weight of the reproductive glands, alteration in sperm concentration, motility and morphology, formation of multinucleated giant cells and vacuoles leading to arrest of spermatogenesis and reduction in seminiferous tubular diameter. The effects were dose dependent with reversible infertility. The results indicate presence of a common antigenic determinants which cross-react with vertebrates and existence of common relation through phylogenetic evolution and their immune responses.

Diphyllobothrium, Anisakis and other fish-borne parasitic zoonoses

Fish-borne parasitic zoonoses such as anisakiasis and diphyllobothriasis occur infrequently in Canada and more work needs to be done on the interactions and transmission dynamics of marine and freshwater anisakids in North America. The diphyllobothriid tapeworms are primarily restricted to the northern Canada. Problems with the specific identification of these parasites from their fish hosts prompted the development of a series of nucleic acid probes. Use of the polymerase chain reaction proved to be quick, accurate and requires little skill, once developed.

A phase II trial of interleukin-2 by continuous infusion and interferon by intramuscular injection in patients with renal cell carcinoma

Fifteen patients with advanced, measurable renal cell carcinoma entered a Phase II clinical trial of interleukin-2 (IL-2) (Teceleukin, Hoffmann-La Roche Inc., Nutley, NJ) and interferon (IFN) (Roferon A, Hoffmann-La Roche Inc.). IL-2 was administered by continuous infusion daily for 4 days and IFN was administered by intramuscular injection daily for 4 days; therapy continued for 4 weeks. Eight men and seven women were treated in this trial (median age, 61 years). Toxicity was moderate to severe with fatigue, nausea, vomiting, hypotension, and elevated blood urea nitrogen bunion and creatinine levels seen in all patients. Two patients achieved a complete remission and two patients achieved a partial remission. The median duration of response was 18 months. IL-2 and IFN is an active combination in the treatment of renal cell carcinoma and warrants further investigation.

Polypodium sp. (Coelenterata) from lake sturgeon (Acipenser fulvescens rafinesque) in the prairie region of Canada

Polypodium sp. is reported for the first time from Canadian waters. It occurred in lake sturgeon (Acipenser fulvescens) eggs, from the Nelson River, Manitoba, and from Cumberland House, Saskatchewan. The prevalence of this parasite was 100% in females with eggs of 3.0 mm diameter or more. One, 4, 25, and 179 infected eggs were collected in gonads with eggs of this size class, but infected eggs were not apparent in individuals with smaller eggs. This is the northernmost occurrence of this parasite reported in North America.

Blocking of Mycobacterium leprae adherence to dissociated Schwann cells by anti-mycobacterial antibodies

The association of Mycobacterium leprae with Schwann cells may represent an early crucial step in M. leprae pathogenesis. Using a dissociated Schwann-cell system and anti-mycobacterial monoclonal and polyclonal antibodies directed against surface and cytoplasmic components, we investigated the nature of M. leprae epitopes that mediate cytadhesion. Antibodies to polysaccharide and lipid components of M. leprae cell wall inhibited cytadhesion, whereas those directed against both surface and cytoplasmic protein epitopes did not show any such effect. No synergistic or antagonistic activity in inhibiting cytadhesion was observed when antibodies were used in combination. Thus, the association of M. leprae with Schwann cells may be mediated collectively by more than one of its lipid/polysaccharide epitopes. Also, a role for humoral immunity in intervention in the initial steps of M. leprae pathogenesis needs to be considered.

A new surgical localization technique for biopsy in patients with nipple discharge

In a series of 12 patients with bloody nipple discharge, a new technique of mammary ductal localization was used to identify the duct responsible for the discharge and assure its complete removal for pathological diagnosis. This procedure utilizes a 30-gauge anterior chamber needle that is gently advanced into the offending duct, and methylene blue dye is injected to outline the involved duct for easy dissection though a circumareolar incision. This provides the pathologist with an intact specimen and avoids the problems associated with specimen roentgenography or loss of a ductal probe during the procedure. Because we feel that all patients with a bloody nipple discharge warrant a biopsy, this procedure provides a safe, rapid, effective method and allows the biopsy to be done on an outpatient basis.

Omnatax in acute urinary tract infection. A clinical study

25 patients of acute urinary tract infection with E. coli received Omnatax, 1 gm. b.d. 80% patients had bacteriologic cure on second day and 96% on fourth day of treatment. When assessed in light of the disappearance or decrease in pyuria and bacteriuria, 72% patients showed excellent response and 28% moderate response at the end of treatment. Clinical cure was achieved in 84% of patients. Mean number of days required for the patients to become symptom-free was 3.5 and mean time to achieve complete bacterial elimination was 1.96 days.

Effects of a derivative of serotonin (deoxyfructoserotonin) and other antileprosy drugs on attachment and uptake of Mycobacterium leprae by Schwann cells in vitro

The association (attachment and/or uptake) of Mycobacterium leprae with cultured Schwann cells was studied at 8 and 72 h in the presence of a new antileprosy compound, deoxyfructoserotonin (DFS), as well as conventional antileprosy drugs such as rifampin (RFP) and 4,4'-diaminodiphenyl sulfone (DDS). DFS significantly inhibited bacterial association with Schwann cells at 8 h. RFP also affected the association of M. leprae but not to the same extent as DFS. A similar inhibition at 8 h was noted when M. leprae but not Schwann cells were pretreated with DFS or RFP for 5 days before infection of cultures, implying that modulation was achieved through some form of drug action on bacteria. DDS had no effect on M. leprae association; however, the combination of DFS and DDS was neither antagonistic nor additive. At 72 h postinfection, when attached but noninternalized bacteria were removed with trypsin-EDTA from Schwann cell cultures containing DFS or RFP, a 50% reduction in the number of bacteria in the drug-treated group was obtained as compared with the numbers in drug-free cultures. This indicated a slow entry of M. leprae into Schwann cells in the presence of these drugs. Collectively, these observations point to differing requirements for late and early association of M. leprae with Schwann cells, besides suggesting a role for DFS and RFP in the prevention and minimization of M. leprae-induced nerve damage in vivo.

Undifferentiated (embryonal) sarcoma of the liver with alpha-1-antitrypsin deposits: immunohistochemical and ultrastructural studies

Periodic acid-Schiff-positive diastase-resistant globules are described in an undifferentiated (embryonal) sarcoma of the liver in a 14-year-old boy. These globules were shown to contain alpha-1-antitrypsin (A-1-AT) protein by immunofluorescence techniques. Further immunohistochemical studied revealed albumin and gamma globulins, but no alpha-feto protein (AFP). Electron microscopic studies showed large, electron-dense bodies consistent with phagolysosomal structures, and distinct from that described in alpha-1-antitrypsin deficiency (A-1-ATD). These findings suggested that the globules in this tumor may represent trapping of serum proteins by the malignant cell. These observations are discussed in connection with recent studies linking the deficiency disease and epithelial hepatic tumors.

Transection denervation of the urinary bladder. An experimental study

In an experimental study in the dog, deliberate partial denervation of the urinary bladder through partial horizontal transection achieved an alteration in detrusor activity similar to that noted in human beings following transection. It is postulated that neural escape is the mechanism responsible in the human.

Evaluation of the role of injection therapy for benign prostatic hypertrophy

Intraprostatic phenol injection treatment was given to 13 cases of benign prostatic hypertrophy (BPH) without urinary retention. Symptomatic improvement was significant, although objective assessment showed neither significant alteration in the size of the prostate nor in the urinary flow rate. Injection therapy is considered inadequate in the relief of prostatic obstruction.

Incisional treatment of obstruction of the female bladder neck

Obstruction of the female bladder neck has been treated in 9 cases by endourethral incision of the bladder neck anteriorly through an operating nasal speculum with very satisfactory results which compare very favourably with those of Y-V plastic reconstruction of the bladder neck in 8 similar cases. The advantages of the incisional technique are simplicity of the procedure, shorter operative time and postoperative stay, and absence of the need for blood transfusion; its complication rate is very low and the procedure may be repeated if necessary.

The pancreas as a transplantable organ

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