Network Formation of DNA/Polyelectrolyte Fibrous Aggregates Adsorbed at the Water-Air Interface

It is discovered that complexes of DNA and hydrophobically modified polyelectrolytes form a rigid network of threadlike or fibrous aggregates at the liquid-gas interface whose morphology can dramatically affect the mechanical properties. While mixed solutions of DNA and poly(N,N-diallyl-N,N-dimethylammonium chloride) (PDADMAC) exhibit no notable surface activity, the complexes formed from DNA with poly(N,N-diallyl-N-butyl-N-methylammonium chloride) are surface-active, in contrast to either of the separate components. Further, complexes of DNA and poly(N,N-diallyl-N-hexyl-N-methylammonium chloride) (PDAHMAC) with its longer hydrophobic side chains exhibit pronounced surface activity with values of surface pressures up to 16 mN/m and dynamic surface elasticity up to 58 mN/m. If the PDAHMAC nitrogen to DNA phosphate molar ratio, N/P, is between 0.6 and 3, abrupt compression of the adsorption layer leads unexpectedly to a noticeable decrease of the surface elasticity. The application of imaging techniques reveals that this effect is a consequence of the destruction of a rigid network of threadlike DNA/polyelectrolyte aggregates at the interface. The toroidal aggregates, which are typical for the bulk phase of DNA/PDADMAC solutions in this range of N/P ratios, are not observed in the surface layer. The observed link between the mechanical properties and interfacial morphology of surface-active complexes formed from DNA with hydrophobically modified polyelectrolytes indicates that tuning polyelectrolyte hydrophobicity in these systems may be a means to develop their use in applications ranging from nonviral gene-delivery vehicles to conductive nanowires.

Neutron reflectivity measurements at the oil/water interface for the study of stimuli-responsive emulsions⋆

Stable stimuli-responsive emulsions between oil and water are formed with an amphiphilic block copolymer bearing polystyrene (PS) and poly(dimethylaminoethyl methacrylate) (PDMAEMA) moieties. Different kinds of emulsions like direct, multiple or inverse ones are reproducibly formed as a function of chemical parameters such as p H and salt concentration. To test the correlation between the different nature of the emulsion and the conformation of the polymer chain at the interface, neutron reflectometry at the oil/water interface was carried out. An original sample cell was built and the procedure to get reliable results with it on the FIGARO reflectometer at the Institut Laue-Langevin is described. Results show that for direct emulsions, the copolymer is much more extended on the water side than on the oil side. In the case where multiple emulsions are stabilized, the conformation is strongly modified and is compatible with a more equilibrated extension of the chain on both sides. The inverse case shows that the extension in oil is stronger than in water. These results are discussed in term of polymer brushes (charged or neutral) extension with respect to salt addition and hydrophobic interactions.

Combined variants in factor VIII and prostaglandin synthase-1 amplify hemorrhage severity across three generations of descendants

Essentials Co-existent damaging variants are likely to cause more severe bleeding and may go undiagnosed. We determined pathogenic variants in a three-generational pedigree with excessive bleeding. Bleeding occurred with concurrent variants in prostaglandin synthase-1 (PTGS-1) and factor VIII. The PTGS-1 variant was associated with functional defects in the arachidonic acid pathway.

SUMMARY

Background Inherited human variants that concurrently cause disorders of primary hemostasis and coagulation are uncommon. Nevertheless, rare cases of co-existent damaging variants are likely to cause more severe bleeding and may go undiagnosed. Objective We prospectively sought to determine pathogenic variants in a three-generational pedigree with excessive bleeding. Patients/methods Platelet number, size and light transmission aggregometry to multiple agonists were evaluated in pedigree members. Transmission electron microscopy determined platelet morphology and granule content. Thromboxane release studies and light transmission aggregometry in the presence or absence of prostaglandin G2 assessed specific functional defects in the arachidonic acid pathway. Whole exome sequencing (WES) and targeted nucleotide sequence analysis identified potentially deleterious variants. Results Pedigree members with excessive bleeding had impaired platelet aggregation with arachidonic acid, epinephrine and low-dose ADP, as well as reduced platelet thromboxane B2 release. Impaired platelet aggregation in response to 2MesADP was rescued with prostaglandin G2 , a prostaglandin intermediate downstream of prostaglandin synthase-1 (PTGS-1) that aids in the production of thromboxane. WES identified a non-synonymous variant in the signal peptide of PTGS-1 (rs3842787; c.50C>T; p.Pro17Leu) that completely co-segregated with disease phenotype. A variant in the F8 gene causing hemophilia A (rs28935203; c.5096A>T; p.Y1699F) was also identified. Individuals with both variants had more severe bleeding manifestations than characteristic of mild hemophilia A alone. Conclusion We provide the first report of co-existing variants in both F8 and PTGS-1 genes in a three-generation pedigree. The PTGS-1 variant was associated with specific functional defects in the arachidonic acid pathway and more severe hemorrhage.

Structure of a liquid/liquid interface during solvent extraction combining X-ray and neutron reflectivity measurements

We have resolved the molecular structure of a bulk oil/water interface that contains amphiphilic ligand molecules using a combination of X-ray and neutron reflectivity measurements for the first time. This new capability can greatly impact future work in the field of ion separation by phase transfer, i.e. liquid/liquid extraction.

"Satan has afflicted me!" Jinn-possession and mental illness in the Qur'an

Mental health stigma in Muslim communities may be partly due to a commonly held belief among some Muslims about the supernatural causes of mental illness (i.e. jinn-possession brought on by one's sinful life). A thematic analysis was carried out on four English translations and the Arabic text of the Qur'an to explore whether the connection between jinn-possession and insanity exists within the Muslim holy book. No connection between spirit-possession and madness or mental illness was found. Pagans taunted and labelled people as jinn-possessed only to ostracize and scapegoat. Linking the labelling of people as jinn-possession to a pagan practice may be used to educate Muslims, so they can reassess their community's stigma towards the mentally ill.

The effect of neutral helper lipids on the structure of cationic lipid monolayers

Successful drug delivery via lipid-based systems has often been aided by the incorporation of 'helper lipids'. While these neutral lipids enhance the effectiveness of cationic lipid-based delivery formulations, many questions remain about the nature of their beneficial effects. The structure of monolayers of the cationic lipid dimethyldioctadecylammonium bromide (DODAB) alone, and mixed with a neutral helper lipid, either diolelyphosphatidylethanolamine or cholesterol at a 1 : 1 molar ratio was investigated at the air-water interface using a combination of surface pressure-area isotherms, Brewster angle microscopy (BAM) and specular neutron reflectivity in combination with contrast variation. BAM studies showed that while pure DODAB and DODAB with cholesterol monolayers showed fairly homogeneous surfaces, except in the regions of phase transition, monolayers of DODAB with diolelyphosphatidylethanolamine were, in contrast, inhomogeneous exhibiting irregular bean-shaped domains throughout. Neutron reflectivity data showed that while the thickness of the DODAB monolayer increased from 17 to 24 Å as it was compressed from a surface pressure of 5-40 mN m(-1), the thickness of the helper lipid-containing monolayers, over the same range of surface pressures, was relatively invariant at between 25 and 27 Å. In addition, the monolayers containing diolelyphosphatidylethanolamine were found to be more heavily hydrated than the monolayers of cationic lipid, alone or in combination with cholesterol, with hydration levels of 18 molecules of water per molecule of lipid being recorded for the diolelyphosphatidylethanolamine-containing monolayers at a surface pressure of 30 mN m(-1) compared with only six and eight molecules of water per molecule of lipid for the pure DODAB monolayer and the cholesterol-containing DODAB monolayer, respectively.

The septic milieu triggers expression of spliced tissue factor mRNA in human platelets

BACKGROUND

Activated platelets have previously-unrecognized mechanisms of post-transcriptional gene expression that may influence hemostasis and inflammation. A novel pathway involves splicing of pre-mRNAs in resting platelets to mature, translatable mRNAs in response to cellular activation.

OBJECTIVES

We asked if bacterial products and host agonists present in the septic milieu induce tissue factor pre-mRNA splicing in platelets from healthy subjects. In parallel, we asked if spliced tissue factor (TF) mRNA is present in platelets from septic patients in a proof-of-principle analysis.

PATIENTS/METHODS

TF pre-mRNA and mRNA expression patterns were characterized in platelets from septic patients and in platelets isolated from healthy subjects activated with bacteria, toxins and inflammatory agonists. Procoagulant activity was also measured.

RESULTS AND CONCLUSIONS

Live bacteria, staphylococcal α-toxin and lipopolysaccharide (LPS) induced TF pre-mRNA splicing in platelets isolated from healthy subjects. Toxin-stimulated platelets accelerated plasma clotting, a response that was blocked by a previously-characterized splicing inhibitor and by an anti-tissue factor antibody. Platelets from septic patients expressed spliced TF mRNA, whereas it was absent from unselected and age-matched control subjects. Tissue factor-dependent procoagulant activity was elevated in platelets from a subset of septic patients. Thus, bacterial and host factors induce splicing of TF pre-mRNA, expression of TF mRNA and tissue factor-dependent clotting activity in human platelets. TF mRNA is present in platelets from some septic patients, indicating that it may be a marker of altered platelet phenotype and function in sepsis and that splicing pathways are induced in this syndrome.

Enhanced cell-associated plasminogen activator pathway but not coagulation pathway activity contributes to motility in metastatic breast cancer cells

BACKGROUND

Activation of tumor cell-associated coagulation and plasminogen activator pathways occurs in malignant disease processes, including breast cancer, and may promote metastatic activity.

OBJECTIVES/METHODS

To compare the coagulation and plasminogen activator pathways of normal and metastatic cells, we examined two cell lines from the MCF-10 family of breast cells: near-normal immortalized MCF-10A cells, and metastatic MCF-10CA1 cells.

RESULTS

MCF-10CA1 cell motility was significantly increased as compared with that of MCF-10A cells. The two cell types supported similar rates of factor Xa generation, plasma thrombin generation, and fibrin formation. MCF-10A cells produced a stable fibrin network, whereas MCF-10CA1 cells lysed the surrounding fibrin network within 24 h of network formation. Importantly, fibrin located proximal to (within 10 microm) the MCF-10CA1 cell surface lysed substantially faster than fibrin located 100 microm from the surface. MCF-10CA1 cells supported significantly increased plasmin generation rates as compared with MCF-10A cells, providing a mechanism for the increased fibrinolytic activity of these cells towards the fibrin network. Metastatic MCF-10CA1 cells had increased expression (mRNA and protein) levels of urokinase plasminogen activator (u-PA) and decreased levels of plasminogen activator inhibitor-1 as compared with MCF-10A cells. Blocking u-PA activity with the active site-directed protease inhibitor amiloride substantially decreased MCF-10CA1 cell motility. Phosphorylated Akt levels were elevated in MCF-10CA1 cells, which partially explains the increased u-PA expression.

CONCLUSIONS

These results suggest that the tumor-associated plasminogen activator pathway, not the coagulation pathway, is a key distinguishing feature between metastatic MCF10-CA1 cells and normal MCF-10A cells.

Islands in the sea: extreme female natal site fidelity in the Australian sea lion, Neophoca cinerea

Pinnipeds (seals, fur seals, sea lions and walrus) form large breeding aggregations with females often remaining faithful to a natal site or area. In these cases, females are philopatric to regional areas on broad geographical scales of hundreds to thousands of kilometers. An investigation of variation in a control region sequence of mtDNA in the Australian sea lion (Neophoca cinerea) has shown a case of extreme female natal site fidelity that has resulted in almost fixed population differentiation across its range (PhiST=0.93). This high level of population subdivision over short geographical distances (approx. 60 km) is unparalleled in any social marine mammal and reflects the unique life-history traits of this rare species. The high level of population subdivision and exclusive female natal site fidelity has important ramifications for conservation management, and poses many interesting questions of both academic and applied interest.

Revision of the Grillotia erinaceus (van Beneden, 1858) species complex (Cestoda: Trypanorhyncha), with the description of G. brayi n. sp

Members of the trypanorhynch cestode genus Grillotia Guiart, 1927 belonging to the Grillotia erinaceus (van Beneden, 1858) species complex are redescribed. The type-species of the genus, G. erinaceus, is redescribed from Raja spp. in the eastern and western north Atlantic and the Mediterranean. The redescription establishes the presence of: an hermaphroditic sac; internal and external seminal vesicles (but absence of an accessory seminal vesicle); a uterine pore; and the attachment of the retractor muscle in the mid-region of the tentacular bulb. G. pseuderinaceus Dollfus, 1969 and G. recurvispinis Dollfus, 1969 from Raja spp. in the Mediterranean are considered to be synonyms of G. erinaceus, following Palm (2004). G. dollfusi Carvajal, 1971 from R. chilensis Guichenot off Chile is redescribed from the paratypes and features of the terminal genitalia, consistent with those of G. erinaceus, are described for the first time. G. musculara (Hart, 1936) is redescribed from new material collected from the type-host, R. rhina (Jordan & Gilbert), off Nanaimo on the western coast of Canada. The features of the terminal genitalia of G. musculara are similar to those of the G. erinaceus group. The morphological features of G. borealis Keeney & Campbell, 2001 from Bathyraja spp. in the Bering Sea and the Sea of Okhotsk are summarised and illustrations of this species provided. G. brayi n. sp. is described from Amblyraja radiata from the coasts of Iceland and Britain. The new species differs from other members of the complex in lacking modified hooks 1 and 1' at the base of the tentacle (differentiating it from G. erinaceus), a long pars vaginalis (differentiating it from G. dollfusi) and uncinate hooks in the band on the external surface of the tentacle (differentiating it from G. musculara). Brief descriptions are provided of two apparently new species of Grillotia currently represented in collections by single specimens.

Two new species ofPseudochristianellaCampbell & Beveridge, 1990 (Cestoda: Trypanorhyncha) from elasmobranch fishes from the Gulf of California, Mexico

Pseudochristionella elegantissima sp. nov. (Cestoda: Trypanorhyncha) is described from the spiral valves of the rays Dasyatis brevis (Garman, 1880) and D. longus (Garman, 1880), from the Gulf of California, Mexico. Also described is P. nudisculo sp. nov. from rays Rhinobatos productus Ayres, 1854, D. longus, Myliobatis longirostris Applegate & Fitch, 1964 and Zapteryx exasperat (Jordan & Gilbert, 1880) from the same location. The species are distinguished from one another and from the only existing species within the genus, P. southwelli Campbel & Beveridge, 1990, by differences in the arrangement of bill-hooks on the external surface of the basal swelling of the tentacle and by the number of hooks in each row of the metabasasl armature.

Interference with nuclear factor kappa B and c-Jun NH2-terminal kinase signaling by TRAF6C small interfering RNA inhibits myeloma cell proliferation and enhances apoptosis

The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of six adaptor proteins (TRAF1-6) links the TNFR superfamily to the nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) transcriptional activators. Unlike other TRAFs, TRAF6 is also involved in Toll-like/interleukin (IL)-1 receptor (TIR) signal transduction. Thus, inhibition of TRAF6 function could interrupt both CD40 (TNFR family) and IL-1 growth signals, pathways critical to myeloma proliferation. To block TRAF6-mediated IL-1 signaling, we constructed small interfering RNA (siRNA) against TRAF6. We found that siRNA targeting the TRAF6 C-terminal (siTRAF6C) receptor interaction domain specifically reduced only TRAF6 protein expression, without affecting TRAF2 or 5 levels, and substantially interfered with IL-1-induced NF-kappaB and c-Jun/AP-1 activation. Inhibition by siTRAF6C was concentration-dependent. SiTRAF6C also significantly reduced myeloma proliferation and enhanced apoptosis in a similar dose-dependent fashion in vitro. More importantly, marked siTRAF6C growth inhibition was detected in vivo when these cells were implanted into the bone marrow of irradiated normal mice. In contrast, introduction of siRNA derived from the TRAF6 Zn-finger domain or an irrelevant siRNA construct failed to alter cell growth or cell death. These studies suggest that TRAF6 may be a new molecular target to block cell signal transduction important for the survival and proliferation of multiple myeloma cells.

Tumour necrosis factor and PI3-kinase control oestrogen receptor alpha protein level and its transrepression function

Oestrogen receptor alpha (ERα) is an oestrogen-activated transcription factor, which regulates proliferation and differentiation of mammary epithelial cells by activating or repressing gene expression. ERα is a critical prognostic indicator and a therapeutic target for breast cancer. Patients with tumours that express higher level of ERα have better prognosis than patients with tumours that are ERα negative or express lower level of ERα. Better prognosis in ERα-positive patients is believed to be due to repression of proinvasive gene expression by ERα. Oestrogen receptor alpha represses gene expression by transrepressing the activity of the transcription factors such as nuclear factor-kappaB or by inducing the expression of transcriptional suppressors such as MTA3. In this report, we show that ERα transrepresses the expression of the proinvasive gene interleukin 6 (IL-6) in ERα-negative MDA-MB-231 breast cancer cells stably overexpressing ERα. Using these cells as well as ERα-positive MCF-7 and ZR-75-1 cells, we show that tumour necrosis factor alpha (TNFα) and the phosphatidylinositol-3-kinase (PI3-kinase) modulate transrepression function of ERα by reducing its stability. From these results, we propose that TNFα expression or PI3-kinase activation lead to reduced levels of ERα protein in cancer cells and corresponding loss of transrepression function and acquisition of an invasive phenotype.

The genus Acanthobothrium (Cestoda : Tetraphyllidea : Onchobothriidae) parasitic in Australian elasmobranch fishes

The onchobothriid tetraphyllidean cestode genus Acanthobothrium van Beneden, 1849, parasitic in the spiral intestine of elasmobranch fishes, was investigated in the Australian region. Thirty-three species are recognised, including 27 that are new. Diagnoses compare the morphological taxonomic characters of all congeners. New species are: Acanthobothrium adlardi; A. angelae; A. arlenae; A. bartonae; A. blairi; A. brayi; A. cannoni; A. chisholmae; A. clarkeae; A. cribbi; A. edmondsi; A. gasseri; A. gibsoni; A. gloveri; A. jonesi; A. lasti; A. laurenbrownae; A. martini; A. mooreae; A. ocallaghani; A. odonoghuei; A. pichelinae; A. robertsoni; A. rohdei; A. stevensi; A. thomasae; and A. walkeri. Additional morphological data are provided for A. australe Robinson, 1965, A. pearsoni Williams, 1962, A. heterodonti Drummond, 1937 and A. urolophi Schmidt, 1973, reported previously from Australia. Acanthobothrium rhynchobatidis Subhapradha, 1955 and A. semnovesiculum Verma, 1928 are reported from Australia for the first time and are redescribed. Additional morphological details are provided for A. ijimae Yoshida, 1917 and A. grandiceps Yamaguti, 1952. Acanthobothrium wedli Robinson, 1959 is redescribed from the type host from New Zealand waters and considered a sister species of A. blairi from Tasmania. Seven new host genera for Acanthobothrium are reported: Hypnos Duméril, 1852 (Hypnidae); Pristiophorus MÜller & Henle, 1837 (Pristiophoridae); Sutorectus Whitley, 1939 (Orectolobidae); Aptychotrema Norman, 1926 and Trygonorrhina MÜller & Henle, 1838 (Rhinobatidae); Parascyllium Gill, 1862 (Parascylliidae); and Aetomylaeus Garman, 1908 (Myliobatididae). Species of Acanthobothrium are reported from the families Hypnidae, Pristiophoridae and Parascylliidae for the first time. New host species for Acanthobothrium are: Pristiophorus cirratus (Latham, 1794); Parascyllium ferrugineum McCulloch, 1911; Sutorectus tentaculatus (Peters, 1865); Aptychotrema vincentiana (Haacke, 1885); Trygonorrhina fasciata MÜller & Henle, 1841; Raja whitleyi Iredale, 1938; Raja cerva Whitley, 1939; Hypnos monopterygium (Shaw & Nodder, 1795); Dasyatis annotata Last, 1987; Urolophus cruciatus (Lacépède, 1804); Urolophus expansus McCulloch, 1916; Urolophus lobatus McKay, 1966; Urolophus paucimaculatus Dixon, 1969; Gymnura australis (Ramsay & Ogilby, 1886); Aetomylaeus nicofii (Schneider, 1801); and Myliobatis australis Macleay, 1881 (Myliobatididae). New host records for Australia include the above 16 elasmobranch species and the following three host species also known to harbour Acanthobothrium in other geographic localities: Rhynchobatis djiddensis (Forsskål, 1775) (Rhynchobatidae); Himantura uarnak (Forsskål, 1775); and Pastinachus sephen (Forsskål, 1775) (Dasyatidae). Four additional records for hosts previously reported for Acanthobothrium from Australian waters are Squalus megalops (Macleay, 1881) (Squalidae), Heterodontus portusjacksoni (Meyer, 1793) (Heterodontidae), Orectolobus maculatus (Bonnaterre, 1788) (Orectolobidae) and Trygonoptera ‘testacea’ MÜller & Henle, 1841 (Urolophidae). An emended diagnosis of the genus, key to Australian species, host-parasite checklist, phylogenetic analysis of the Australian species and an updated world list of all species of Acanthobothrium are provided.

Grillotia borealis sp. n. (Cestoda: Trypanorhyncha) from five species of Bathyraja (Rajiformes: Arhynchobatidae) in the North Pacific Ocean with comments on parasite enteric distribution

A new trypanorhynch cestode, Grillotia borealis sp. n., is described from the spiral intestines of softnose skates of the genus Bathyraja collected from subarctic waters of the North Pacific Ocean: B. parmifera (Bean) (type host), B. aleutica (Gilbert) and B. interrupta (Gill et Townsend) from the Bering Sea and B. minispinosa Ishiyama et Ishihara and B. sminovi (Soldatov et Pavlenko) from the Sea of Okhotsk off Japan. The new species is distinguished from other species of Grillotia by possession of the following combination of characters: four hooks per principal row, hooks 4(4') distinctly separated from hooks 3(3') of principal row, principal rows separated by 13-15 intercalary hooks in 2-3 rows, hooks 2(2') and 3(3') change in form along their respective files, hooks 1(1') do not change in form along the file, a broad band of microhooks on the external tentacular face, intermediary hooks are lacking, absence of a special basal armature, origin of the retractor muscle near middle of the bulb, average scolex ratio of 1:3:2:0.1, and a hermaphroditic sac. Grillotia borealis consistently favoured the most anterior regions of the spiral intestine. Seventy-one per cent of 21 attached worms occupied the most anterior chamber of the spiral valve and 52 per cent were embedded in the anterior surface of the spiral valve whorls. Factors which may limit the distribution of G. borealis within the spiral intestine of its host are discussed. Statistically significant differences occur in the mucosal morphology of B. aleutica and B. parmifera for villus length, diameter, spatial arrangement and number per unit area along the antero-posterior axis of the spiral intestine.

Grillotia australis n. sp. and G. pristiophori n. sp. (Cestoda: Trypanorhyncha) from Australian elasmobranch and teleost fishes

Two new species of Grillotia are described from elasmobranch and teleost fishes from south-eastern Australia. G. australis n. sp., from the Australian angel shark Squatina australis. Regan, most closely resembles G. smarisgora (Wagener, 1854) and G. angeli Dollfus, 1969, differing from both species in the presence of smaller bulbs, two or occasionally three hooks in each intercalary row in the basal region, reduced to one in the metabasal region compared with four or five hooks in the metabasal region of G. smarisgora and a single hook in G. angeli, and in the limited extent of the band of hooklets on the external surface in the basal region of the tentacle, a region which is covered with hooks in G. smarisgora. Plerocerci of this species were found in the mackerel Trachurus declivis (Jenys) (site not known) from Tasmania. G. pristiophori n. sp., from the saw sharks Pristiophorus cirratus (Latham) and P. nudipinnis Günther, most closely resembles G. spinosissima Dollfus, 1969 in possessing a scolex covered with spiniform microtriches, but differs in having six rather than five hooks in each principal row, no intercalary hooks and by possessing a band of hooklets on the external surface of the tentacle which diminishes distally into a single file, rather than persisting as a band eight to nine files wide. G. pristiophori is the first trypanorhynch to be recorded from saw-sharks.

Phosphatidylinositol 3-kinase/AKT-mediated activation of estrogen receptor alpha: a new model for anti-estrogen resistance

Estrogen receptors (ERs) mediate most of the biological effects of estrogen in mammary and uterine epithelial cells by binding to estrogen response elements in the promoter region of target genes or through protein-protein interactions. Anti-estrogens such as tamoxifen inhibit the growth of ER-positive breast cancers by reducing the expression of estrogen-regulated genes. However, anti-estrogen-resistant growth of ER-positive tumors remains a significant clinical problem. Here we show that phosphatidylinositol (PI) 3-kinase and AKT activate ERalpha in the absence of estrogen. Although PI 3-kinase increased the activity of both estrogen-independent activation function 1 (AF-1) and estrogen-dependent activation function 2 (AF-2) of ERalpha, AKT increased the activity of only AF-1. PTEN and a catalytically inactive AKT decreased PI 3-kinase-induced AF-1 activity, suggesting that PI 3-kinase utilizes AKT-dependent and AKT-independent pathways in activating ERalpha. The consensus AKT phosphorylation site Ser-167 of ERalpha is required for phosphorylation and activation by AKT. In addition, LY294002, a specific inhibitor of the PI 3-kinase/AKT pathway, reduced phosphorylation of ERalpha in vivo. Moreover, AKT overexpression led to up-regulation of estrogen-regulated pS2 gene, Bcl-2, and macrophage inhibitory cytokine 1. We demonstrate that AKT protects breast cancer cells from tamoxifen-induced apoptosis. Taken together, these results define a molecular link between activation of the PI 3-kinase/AKT survival pathways, hormone-independent activation of ERalpha, and inhibition of tamoxifen-induced apoptotic regression.

Proemotobothrium n. g. (Cestoda: Trypanorhyncha), with the redescription of P. linstowi (Southwell, 1912) n. comb. and description of P. southwelli n. sp

A new genus, Proemotobothrium (Trypanorhyncha: Otobothriidae), is erected to contain P. linstowi (Southwell, 1912) n. comb. (syn. Otobothrium magnum Southwell, 1924) and P. southwelli n. sp. The new genus is characterised by two bothridia, paired bothridial pits, an acraspedote scolex, elongate bulbs, four hooks per principal row, hooks 4 (4') being small and uncinate, a single, filiform, intercalary hook between each principal row and by the arrangement, in tandem, of the two or three extra hooks of the armature of the external surface of the tentacle, a pattern previously known only in the family Mixodigmatidae. The two species are distinguished from one another on the basis of measurements of the scolex and bulbs, the sizes of the hooks of the principal rows and by the number and size of the additional hooks in the linear arrays on the external surface of the tentacle.

Emendation of the generic diagnosis of Tylocephalum (Cestoda: Lecanicephalidea: Tetragonocephalidae), and description of Tylocephalum brooksi n. sp

A new species of Tylocephalum is described from the spiral intestine of the cownose ray Rhinoptera bonasus taken off Venezuela. Tylocephalum brooksi n. sp. is the third species described parasitizing this host species, along with T. pingue and T. bonasum. T. brooksi is similar to congeners in the possession of a scolex with a fungiform pars apicalis, craspedote segmentation, circummedullary vitellarium, external seminal vesicle, bilobed ovary, and medioventral uterus. However, this species differs from all previously described species of Tylocephalum in having a collar around the base of the pars apicalis densely covered by large digitiform processes (microtriches?), and an internal seminal vesicle. The internal seminal vesicle is a feature currently used to differentiate Tetragonocephalum from Tylocephalum. Its presence in T. brooksi indicates that it should be considered a specific instead of a generic character. An emended diagnosis of Tylocephalum is proposed excluding this feature, along with distribution of the testes in the preovarian field and circummedullary distribution of vitelline follicles. Species of Tylocephalum and Tetragonocephalum are reviewed on the basis of original descriptions, and 2 distinct morphological groups of species defined. Species of the Tetragonocephalum group possess a combination of an acraspedote strobila, segments much longer than wide, testes limited to the region anterior to the cirrus sac, vitellarium of lateral bands, conspicuously enlarged genital atrium and pore, cirrus sac dorsal to genital atrium, and bisaccate uterus. Species of the Tylocephalum group differ from Tetragonocephalum in possession of a craspedote strobila, segments more quadrangular, testes distributed throughout the preovarian field, inconspicuous genital atrium, uniformly saccate uterus, cirrus sac lateral to genital atrium, and probable circummedullary vitellaria in all species.

A redescription of Pintneriella Yamaguti, 1934 (Cestoda: Trypanorhyncha and an examination of its systematic position

Specimens of Pintneriella musculicola Yamaguti, 1934 are redescribed based on paratype material and specimens subsequently allocated to the species by its describer. The cestode species is characterised by two bothridia, a typical heteroacanthous armature with a distinctive basal swelling and basal armature, a space between hook files 1 and 1', nine hooks per principal row, no intercalary hooks and bands of hooklets or chainettes but a distinctive space on the external surface of the tentacle between hook files 9 and 9'. The strobilia is unknown. The features described indicate that Pintneriella is a valid genus within the Heteracanthoidea. Its currently known morphological features do not allow its allocation to an existing family.

Paroncomegas araya (Woodland, 1934) n. gen. et comb. (Cestoda: Trypanorhyncha: Eutetrarhynchidae) from the freshwater stingray Potamotrygon motoro in South America

The trypanorhynch cestode originally designated Tentacularia araya is redescribed from its type host, Potamotrygon motoro (Potamotrygonidae), from specimens recently collected in Argentina and type material. The armature combines features of Eutetrarhynchus, Oncomegas, and Dollfusiella, indicating that its current placement in Eutetrarhynchus is incorrect and that the species represents a new genus. Paroncomegas n. gen. is proposed within the Eutetrarhynchidae Guiart, 1927, to accommodate Tentacularia araya as Paroncomegas araya n. comb. Eutetrarhynchus differs from Paroncomegas in the absence of a basal armature and basal swelling on the tentacles, from Dollfusiella by lacking macrohooks associated with the basal armature, and from Oncomegas, which possesses an asymmetrical basal swelling on the internal face of the tentaclc and a single macrohook on the external face of the basal armature. Paroncomegas is unique among these genera in possessing a chainette in the basal armature. All other genera currently recognized within the Eutetrarhynchidae can be distinguished from Paroncomegas by a distinct spatial divergence of hooks files 1(1'), resulting in a prominent space in views of the internal face. Two different morphotypes of P. araya can be distinguished in the material from Argentina, both infecting the same individual host specimens. They differ in the number and size of mature and gravid segments. Other characters concerning the tentacle armature, scolex features, and reproductive anatomy remain comparable.

Systematics of the Eucestoda: advances toward a new phylogenetic paradigm, and observations on the early diversification of tapeworms and vertebrates

Evolutionary relationships of the Eucestoda have received intense but sporadic attention over the past century. Since 1996, the landscape has dramatically changed with respect to our knowledge of the phylogenetic relationships among the tapeworms. The 2nd International Workshop for Tapeworm Systematics (IWTS) held in Lincoln, Nebraska in October of that year provided the catalyst for development of novel hypotheses for inter- and intraordinal phylogeny. The working-group structure of the 2nd IWTS and results of phylogenetic studies are briefly introduced in the present manuscript. Higher-level phylogenies derived from parsimony analysis of independent data bases representing comparative morphology or molecular sequences were largely congruent and supported monophyly for the Eucestoda. The Caryophyllidea are basal; difossate forms such as the Pseudophyllidea are primitive; tetrafossates including the Tetraphyllidea, Proteocephalidea, Nippotaeniidea, Tetrabothriidea and Cyclophyllidea are derived; and hypotheses differed in the placement of the Trypanorhyncha and the Diphyllidea. These studies may provide a foundation for resolution of inter- and intra-ordinal relationships for the tapeworms. Additionally, the first comprehensive phylogenetic hypotheses for the Pseudophyllidea, Diphyllidea, Trypanorhyncha, the paraphyletic Tetraphyllidea + Lecanicephalidea, Proteocephalidea and Cyclophyllidea were developed during and subsequent to the 2nd IWTS. The stage is now set for continued and rapid advances in our understanding of the eucestodes. These studies have also served to re-emphasise the rich genealogical diversity of tapeworms and the temporally deep history for their origin. A co-evolutionary history and radiation of eucestodes may involve deep co-speciation with vertebrate host taxa, accompanied by some level of colonisation and extinction, extending into the Palaeozoic, minimally 350-420 million years ago.

Preliminary cladistic analysis of genera of the cestode order Trypanorhyncha Diesing, 1863

A preliminary cladistic analysis was carried out on the 49 currently recognised genera of the order Trypanorhyncha. Forty-four characters were analysed; a functional outgroup was used for scolex and strobilar characters, while Nybelinia was utilised to polarise characters related to the rhyncheal system. Eight well-resolved clades were evident in the resultant cladogram, which is compared with existing phenetic classifications. An analysis of families resulted in a similar clustering of taxa to that observed in the case of the genera. The results suggest that two key characters used in existing classifications, namely the presence of sensory fossettes on the bothridia and the development of atypical heteroacanth and poeciloacanth armatures from typical heteroacanth armatures, have occurred on several occasions. Some clades provide support for the arrangements used in current classifications. Suggestions are made for future avenues of research which might provide more robust phylogenetic data for the Trypanorhyncha.

Histopathological reactions of the blue shark, Prionace glauca, to postlarvae of Hepatoxylon trichiuri (Cestoda: Trypanorhyncha: Hepatoxylidae) in relationship to scolex morphology

Postlarvae of the cestode Hepatoxylon trichiuri (Holten, 1802) were found attached to the surface of viscera of Prionace glauca (Linnaeus, 1758) taken from Atlantic coastal waters off the south coast of Massachusetts, USA. Gross anatomy of the attachment site shows a quadripartite rim surrounding a deep pit with holes corresponding to the penetration site of each tentacle. Hyperplasia of the liver capsule into outgrowths at the attachment site conform to the attachment of the bothridia. The cuboidal epithelium of the liver capsule became columnar forming papillary outgrowths, with a dense fibrotic reaction beneath the attachment site and infiltration by leukocytes and pigment containing granulocytic cells. Blood sinusoids beneath the attachment site are greatly enlarged. Postlarvae attached to the surface of the epigonal organs of three blue sharks were not accompanied by reactions. SEM examination of the scolex of H. trichiuri postlarvae revealed fused pairs of bothridia within infolded muscular lateral rims, porose tegument devoid of microtriches and a bilateral plane of symmetry in the tentacular armature.

Echinobothrium raschii n. sp. (Cestoda: Diphyllidea) from Rhinoraja longi (Chondrichthyes, Rajoidei) in the Bering Sea

Echinobothrium raschii n. sp. from the spiral intestine of Rhinoraja longi in the Bering Sea, off the Aleutian Islands of Alaska is described. On the basis of the armature of the rostellum and cephalic peduncle the new species most closely resembles Echinobothrium acanthinophyllum, Echinobothrium acanthocolle, Echinobothrium coronatum and Echinobothrium helmymohamedi. Echinobothrium raschii n. sp. can be differentiated from all but E. coronatum by the possession of a continuous row of 27-36 lateral hooklets per side on the scolex and 21-26 spines per row on the cephalic peduncle. In E. acanthinophyllum there are fewer spines per row on the cephalic peduncle (13) and only 2 groups of 4 lateral hooklets per side instead of a continuous row of lateral hooklets; E. acanthocolle bears only 5 spines per row on the cephalic peduncle and has no lateral hooklets; E. helmymohamedi has 10-12 spines per row on the cephalic peduncle and bears no lateral hooklets. Echinobothrium raschii n. sp. can be distinguished from E. coronatum by number of spines per row on the cephalic peduncle (average 24 vs. 32) and testes number (17-23 vs. 9-11). The combined characters of 2 groups of 23-25 large apical hooks, a continuous alternating row of 27-36 hooklets on each side of the scolex between the groups of large apical hooks, 21-26 spines per row on the cephalic peduncle, and 17-23 testes per segment differentiates E. raschii from all other species of Echinobothrium. The prevalence of infection was 50% and mean intensity of infection was 8.7 worms per host. The current status of the genus Echinobothrium is discussed and a tabulation of the species presented.

Whole blood analysis of gluconeogenic amino acids for estimation of de novo gluconeogenesis using pre-column o-phthalaldehyde derivatization and high-performance liquid chromatography

By measuring the potential glucose precursors entering and existing the liver, an estimate of the maximal rate of de novo gluconeogenesis can be made. Traditionally, measurements of gluconeogenic amino acids have been extracted from full amino acid profiles using conventional ion-exchange chromatography. These methods are labor intensive, costly procedures that do not focus on gluconeogenic amino acids. The present paper describes a method that provides an accurate whole blood gluconeogenic amino acid profile (intra-assay coefficients of variation from 0.8 to 1.1% and inter-assay coefficients of variation from 2.9 to 4.3%) using high-performance liquid chromatography with o-phthalaldehyde chemistry. This automated method is relatively fast (injection to injection time = 30 min), and linear (r2 > 0.996) for both standards and deproteinized whole blood. Furthermore, it is economical and capable of assessing gluconeogenic amino acids across a broad physiological range of concentrations using small sample volumes.

Revision of the family Pterobothriidae Pintner, 1931 (Cestoda : Trypanorhyncha)

The trypanorhynch cestode family Pterobothriidae Pintner, 1931 is revised. Valid species of the genus Pterobothrium Diesing, 1850 are defined. Ten species of pterobothriid cestodes, including five new species, are described from elasmobranchs taken in waters off Australia, the Indian Ocean, the Atlantic coast of North America, and in the S Atlantic off Senegal, West Africa. Six of the species, P. acanthotruncatum, P. lintoni, P. lesteri, sp. nov., P. pearsoni, P. southwelli, sp. nov., and P. australiense, sp. nov., are described from fishes in Australian waters and the Indian Ocean. The armature of Pterobothrium heteracanthum Diesing, 1850 is redescribed using light and scanning electron microscopy. New intermediate hosts, locality records, and synonyms are provided for P. crassicolle Diesing, 1850 from Atlantic coastal waters of North and South America. Details of the entire armature of Pterobothriurn crassicolle Diesing, 1850 from Micropogonias furnieri (Desmarest) from Rio de Janiero are included. Two new species of Pterobothrium, P. kingstoni, sp. nov., and P. senegalense, sp. nov., are described from dasyatid rays in waters of the Atlantic Ocean. P. kingstoni, sp. nov., from dasyatid rays taken in coastal waters off New England and Chesapeake Bay, Virginia, is distinguished by the presence of a wide band of hooks on the external face of the tentacle, a single row of 4 intercalary hooks, absence of a basal swelling and special armature and by a transverse base on hooks 4(4′) of each principal metabasal row. Pterobothrium senegalense, sp. nov., is described from Dasyatis centroura from Gorbe, Senegal, West Africa, and is distinguished by 3 intercalary rows of hooks that run over onto the external tentacular face but never occupy the midline, by the size and position of hooks in the first intercalary row, and position of the first intercalary row relative to the second and third rows. Pterobothrium southwelli, sp. nov., P. lesteri, sp. nov., and P. pearsoni are described from teleosts in the Indian Ocean. P. southwelli, sp. nov., is distinguished from congeners by a distinctive basal armature and prominent band of hooks on the external surface, a single intercalary row, uncinate hooks l(1′) in all metabasal principal rows, and absence of dentate hooks from the metabasal rows. P. lesteri, sp. nov., is unique in the combination of a basal row of 3 small hooks, a band of hooks, a single intercalary row of 3–4 hooks and in the possession of hooks 4(4′) with dentate tips and hooks 5(5′) with filamentous tips. P. pearsoni differs in possessing a band of hooks and 2 rows of intercalary hooks per principal row, basal armature restricted to the external surface, and uncinate hooks l(1′) combined with dentate hooks 4(4′)–5(5′) in all metabasal rows. Three species from Australian waters, P. lintoni (MacCallum, 1916), P. australiense, sp. nov., and P. acanthotruncatum, lack a well-developed band of hooks on the external face of the metabasal armature. P. lintoni (MacCallum, 1916), the senior synonymn of P. malleum MacCallum, 1916) and P. dasybati Yamaguti, 1934, is described from types and compared with new specimens from the Woods Hole region (USA) and Australia. New host records for adults and plerocerci of P. lintoni are reported from Australian waters off Queensland and South Australia. Pterobothrium chaeturichthydis (Yamaguti, 1952) is considered a synonym of P. lintoni. P. australiense, sp. nov., from Pristis zijsron near Townville, Queensland, differs from congeners in the possession of slender falcate hooks 1(1′), notched tips of hooks 5(5′), a single intercalary row of 3 hooks, and total absence of a band of hooks on the external tentacular face. P. australiense, sp. nov., is similar to P. acanthotruncatum but has falcate hooks at the start of each principal row, lacks the pairs of satellite microhooks on the external face adjacent to the principal rows and possesses a band of microhooks in the basal region of the external face of the tentacle. P. acanthotruncatum is reported from new hosts in Australia and from Sri Lanka and India. A key to the 12 currently recognised species of pterobothriids is provided.

Tentacular armature of the trypanorhynch cestode Synbothrium filicolle (Linton, 1890) (= Pterobothrium heteracanthum Diesing, 1850) and its taxonomic significance

The armature of Synbothrium filicolle (Linton, 1890) is shown, based upon examination of Linton's specimens, by light and scanning electron microscopy. This species, a junior synonym of Pterobothrium heterocanthum Diesing 1850, represents the species upon which the genus Pterobothrium Diesing, 1850 was created, but details of the external surface of the tentacular armature have never been established with certainty. A longitudinal band of spiniform microhooks on the external tentacular surface clearly distinguishes this species from the otherwise similar Pterobothrium acanthotruncatum Escalante and Carvajal, 1984. The band merges with a triangular group of uncinate hooks in the basal armature not previously described. The 2 Brazilian species, P. crassicolle Diesing, 1850 and P. heteracanthum, used in the creation of the genus, both possess an external band of hooks. Three different modifications of the armature of the external surface have been described for species of Pterobothrium. These include a discrete band of microhooks, small groups of microhooks continuous with the intercalary rows, and the absence of a band of microhooks.

Validity and reliability testing of the Prenatal Psychosocial Profile

Two studies of low-income pregnant women (N = 179) were done to examine the validity and reliability of the Prenatal Psychosocial Profile (PPP). The PPP, a composite of the Rosenberg Self-Esteem Scale, the Support Behaviors Inventory, and a newly developed measure of stress, is a brief, comprehensive clinical assessment of psychosocial risk during pregnancy. Construct validity of the stress scale was supported by theoretically predicted negative correlations with self-esteem, partner support, and support from others (N = 91). Convergent validity of the stress scale was demonstrated by a correlation of .71 with the Difficult Life Circumstances Scale. Adequate levels of internal consistency were found. Interrelationships between the four subscales were consistent with the underlying conceptualization, and there was beginning evidence of the factorial independence of the subscales.

A PCR based method to determine the Kalow allele of the cholinesterase gene: the E1k allele frequency and its significance in the normal population

The Kalow allele for cholinesterase is a quantitative variant of the usual gene and has been shown to result from a single base pair change in the DNA. A new method based on the polymerase chain reaction to distinguish Kalow alleles of the cholinesterase gene was developed. Using the amplification refractory mutagenesis system, two different reactions distinguished the presence of a guanine (normal E1u allele) from that of an adenine (Kalow E1k allele) at nucleotide 1615 within the coding sequences of the gene. The frequency of the Kalow allele in our sample of 51 persons was determined to be 20%. The mean total cholinesterase activity in heterozygotes was 90% of that in persons who typed as E1uE1u homozygotes. Two E1kE1k homozygotes were identified and their cholinesterase activities were the two lowest measured.

Multipin peptide synthesis at the micromole scale using 2-hydroxyethyl methacrylate grafted polyethylene supports

The multipin peptide synthesis procedure has been adapted to allow the synthesis of peptides at micromole loadings. The original solid pin support was replaced with a detachable crown-shaped polyethylene support with an increased surface area. In addition, the polyethylene crowns were radiation-grafted with 2-hydroxyethyl methacrylate monomer instead of acrylic acid to yield hydroxy functionalized supports with a larger concentration of polymer and hence a larger peptide capacity. Fmoc-beta-Alanine was directly esterified to the HEMA hydroxy groups with subsequent addition of a diketopiperazine-forming handle for peptide attachment. Peptides varying in length from 10 to 25 residues were assembled at a number of loadings from 1.0 to 2.2 mumol. Purity of peptides at all loadings was equal to, and in some instances superior to, that achieved on conventional solid-phase supports.

Cognitive patterns in school-age children with end-stage liver disease

Although children with end-stage liver disease (ESLD) have been found to have cognitive delays, the relationship between patterns of cognitive function and diagnostic category, age of onset, duration and severity of disease has not been assessed before transplantation. Verbal and performance IQ (VIQ, PIQ) scores and scores on Bannatyne's cognitive factors for 43 children with ESLD were compared with those of 15 control children with cystic fibrosis (CF) and with existing normative data. Children with biliary atresia had deficits in PIQ, spatial and sequential scores. Children with alpha-1 antitrypsin deficiency did not differ significantly from CF controls but did show deficits compared with normative data. Children with onset of disease in the first year of life had deficits on all cognitive measures compared with both control groups. In contrast, children with later onset differed from the normative population only on VIQ and the acquired knowledge factor. In multiple regression analyses, duration of disease and indexes of liver dysfunction combine to predict cognitive scores. These preliminary findings suggest that children with early onset of liver disease are at high risk for cognitive impairment.

The action of chelating agents in experimental uranium intoxication in mice: variations with structure and time of administration

The determination of the relative abilities of 11 chelating agents to enhance the urinary and fecal excretion of uranium when administered 10 min after uranyl acetate dihydrate (UAD) in mice showed that the most effective of these were Tiron, desferrioxamine, and 1,2-dimethyl-3-hydroxypyrid-4-one. An increase in the interval between UAD administration and that of the chelating agent drastically reduces the net mobilization of the uranium by the chelating agents examined. When given shortly after UAD, Tiron produced the greatest reduction in renal and bone levels of uranium. None of the chelating agents were able to affect the bone levels of uranium when administered 24 hr or more after the administration of the UAD.

Comparative iron mobilizing actions of deferoxamine, 1,2-dimethyl-3-hydroxypyrid-4-one, and pyridoxal isonicotinoyl hydrazone in iron hydroxamate-loaded mice

A comparison was made of the actions of deferoxamine (DFX), 1,2-dimethyl-3-hydroxypyrid-4-one (L1), and pyridoxal isonicotinoyl hydrazone (PINH) in mobilizing and promoting excretion of iron in mice loaded with iron-acetohydroxamic acid complex. DFX was given ip, while L1 and PINH were given po. Each was given daily for four days at 300 mg/kg/day, and total excreta were collected 24 hr after each administration. Total iron excreted over the 4-day period, expressed as micrograms/mouse, were: Controls, 26; PINH-treated, 31; DFX-treated, 162; and L1-treated, 208. Measurements of iron in selected organs 96 hr after the last administration of each compound revealed that treatment with L1 and DFX induced significant reductions of iron concentrations in kidneys (16% and 17%, respectively) and in pancreas (18% and 19%, respectively). In addition, L1 treatment led to a significant reduction in the liver iron burden (11%), an action not seen after treatment with DFX. None of the compounds reduced iron concentrations in heart, the most critical organ for toxicity of transfusional siderosis. The synthetic routes for preparation of L1 and PINH are described in detail.

Synthesis of peptide analogues using the multipin peptide synthesis method

Modification of the multipin peptide synthesis method which allows the simultaneous synthesis of large numbers of different peptide analogues is described. Peptides were assembled on polyethylene pins derivatized with a 4-(beta-alanyloxymethyl)benzoate (beta-Ala-HMB) handle. For comparative purposes, peptides were also assembled on the diketopiperazine-forming handle N epsilon-(beta-alanyl)lysylprolyloxylactate. In model studies it was demonstrated that beta-Ala-HMB-linked peptides were cleaved from polyethylene pins with dilute sodium hydroxide or 4% methylamine/water to yield analogues with beta-Ala-free acid (beta-Ala-CO2H) and beta-Ala-methylamide (beta-Ala-CONHCH3), respectively. To assess the suitability of this approach for T-cell determinant analysis, analogues of a known T-cell determinant were synthesized with the various C-terminal endings. Peptides were characterized by amino acid analysis and fast atom bombardment-mass spectrometry. HPLC of the crude cleaved peptides indicated that 22 of the 24 peptides were greater than 95% pure. These crude peptide solutions were nontoxic in sensitive cell culture assays without further purification. All three cleavage procedures gave comparable activities in T-cell proliferation assays. These results demonstrate the potential of the multipin peptide synthesis method for the production of large numbers of different peptide analogues.

Effects of DL-alpha-difluoromethylornithine, 4-deoxypyridoxine and methylglyoxal bis(guanylhydrazone) on allograft prolongation

DL-alpha-difluoromethylornithine (DFMO), 4-deoxypyridoxine (4-DOP), and methylglyoxal bis (guanylhydrazone) (MGBG) were tested as inhibitors of acute skin graft rejection. Proximal full thickness tail skins were exchanged between C57BL/6 and Balb/C mice. Distal autografts were placed to monitor healing. Inhibitors were given singly or in combination, either orally or by injection, in various schedules to 10 groups of mice. Compared to controls, singly treated mice had significant mean prolongation of allografts ranging from 126% to 141%. Likewise, DFMO plus MGBG extended mean time of complete rejection ranging from 172% to 206%. Autografts remained intact. Some grafts persisted after discontinued immunosuppression. Complete rejection was preceded by a decline in vascularity of the graft bed and/or gradual replacement by host tissue. Graft protection in such stringent circumstances i.e., the use of skin in strains with complete histoincompatibility at the H-2 MHC loci, clearly indicate the anti-rejection effects of polyamine synthesis inhibitors. Moreover, primary and secondary effects of DFMO establish the critical role of polyamine pathway activation in acute rejection. In doses and schedules used, toxicity was encountered when DFMO and 4-DOP were used in combination and when increased amounts of MGBG were administered.

Large histiocytes in the choroid of leukemic patients

We identified large histiocytes as a prominent feature in the choroid of eyes obtained at autopsy in seven of nine patients who died of leukemia. The eyes of four of the seven patients affected had leukemic choroidal infiltrates, and a majority had similar-appearing histiocytes identified in spleen or bone marrow. The significance of these cells is undetermined; we postulate that these macrophages are ingesting debris of degenerating leukemic cells.