Sterile-water negative pressure instillation therapy for complex wounds and NPWT failures.

OBJECTIVE: To investigate use of negative pressure wound therapy (NPWT) combined with instillation for patients either presenting with a complex wound or after failure of classic NPWT. METHOD: A retrospective case series study conducted on patients treated using an NPWT instillation system (V.A.C. Instill; KCI Inc.) from January to December 2012. The instillation machine was used with pure saline so as not to interfere with local antibacterial solutions. Two clinical indications-patients presenting either large undermining, deep inaccessible wounds or infected wounds and those for whom conventional NPWT had proved ineffective, were analysed-with efficacy of the promotion of granulation tissue as the primary outcome. Length of instillation time, the rhythm and the amount of liquid to be injected compared with the estimated volume of the cavity were also evaluated. RESULTS: Twenty-four patients were included in this series--12 post-NPWT failures and 12 complex wounds-with positive outcomes in 23 cases. Surgical closure was realised after promotion of granulation tissue, using either flaps or skin grafts alone, or combined with previous application of a dermal substitute. No complications linked to instillation were observed during the period of use. CONCLUSION: The results of this case series suggests that use of NPWT combined with pure saline instillation could have a positive impact on the healing trajectory of patients with complex wounds or after failure of classic NPWT.

Long-term efficacy of ciliary muscle gene transfer of three sFlt-1 variants in a rat model of laser-induced choroidal neovascularization.

Inhibition of vascular endothelial growth factor (VEGF) has become the standard of care for patients presenting with wet age-related macular degeneration. However, monthly intravitreal injections are required for optimal efficacy. We have previously shown that electroporation enabled ciliary muscle gene transfer results in sustained protein secretion into the vitreous for up to 9 months. Here, we evaluated the long-term efficacy of ciliary muscle gene transfer of three soluble VEGF receptor-1 (sFlt-1) variants in a rat model of laser-induced choroidal neovascularization (CNV). All three sFlt-1 variants significantly diminished vascular leakage and neovascularization as measured by fluorescein angiography (FA) and flatmount choroid at 3 weeks. FA and infracyanine angiography demonstrated that inhibition of CNV was maintained for up to 6 months after gene transfer of the two shortest sFlt-1 variants. Throughout, clinical efficacy was correlated with sustained VEGF neutralization in the ocular media. Interestingly, treatment with sFlt-1 induced a 50% downregulation of VEGF messenger RNA levels in the retinal pigment epithelium and the choroid. We demonstrate for the first time that non-viral gene transfer can achieve a long-term reduction of VEGF levels and efficacy in the treatment of CNV.

Effects of ciliary muscle plasmid electrotransfer of TNF-alpha soluble receptor variants in experimental uveitis.

Intraocular inflammation has been recognized as a major factor leading to blindness. Because tumor necrosis factor-alpha (TNF-alpha) enhances intraocular cytotoxic events, systemic anti-TNF therapies have been introduced in the treatment of severe intraocular inflammation, but frequent re-injections are needed and are associated with severe side effects. We have devised a local intraocular nonviral gene therapy to deliver effective and sustained anti-TNF therapy in inflamed eyes. In this study, we show that transfection of the ciliary muscle by plasmids encoding for three different variants of the p55 TNF-alpha soluble receptor, using electrotransfer, resulted in sustained intraocular secretion of the encoded proteins, without any detection in the serum. In the eye, even the shorter monomeric variant resulted in efficient neutralization of TNF-alpha in a rat experimental model of endotoxin-induced uveitis, as long as 3 months after transfection. A subsequent downregulation of interleukin (IL)-6 and iNOS and upregulation of IL-10 expression was observed together with a decreased rolling of inflammatory cells in anterior segment vessels and reduced infiltration within the ocular tissues. Our results indicate that using a nonviral gene therapy strategy, the local self-production of monomeric TNF-alpha soluble receptors induces a local immunomodulation enabling the control of intraocular inflammation.

Drainage of fluorescent liposomes from the vitreous to cervical lymph nodes via conjunctival lymphatics.

The use of liposomes as carriers for the delivery of biologically active molecules into the eye is of major interest. Indeed, encapsulation of biologically active molecules in liposomes may increase their bioavailability and may induce a sustained release, thus avoiding repeated intraocular injections and reducing side effects. We describe here the fate of rhodamine-conjugated liposomes (Rh-Lip) injected into the vitreous of normal Lewis rats. Twenty-four hours after intravitreal injection fluorescent liposomes were detected in the vitreous, the inner layer of the retina and to a lesser extent in the anterior segment of the eye. In addition, numerous Rh-Lip were also observed in the episclera and conjunctival stroma, in conjunctival lymphatic vessels and cervical lymph nodes (LN) draining the conjunctiva and the eye. In the LN, Rh-Lip were taken up by resident macrophages adjacent to CD4+ and CD8+ T cells. Thus, intravitreal injection of anti-inflammatory drugs loaded in liposomes could modulate the ocular immune microenvironment. In addition the passage of drugs into the cervical LN could alter the immune status of these LN and contribute to the regulation of intraocular inflammation. Our results suggest that this phenomenon should be taken into account to design new therapies based on intraocular drug administration.

Ocular and systemic bio-distribution of rhodamine-conjugated liposomes loaded with VIP injected into the vitreous of Lewis rats.

PURPOSE: Local delivery of therapeutic molecules encapsulated within liposomes is a promising method to treat ocular inflammation. The purpose of the present study was to define the biodistribution of rhodamine-conjugated liposomes loaded with vasoactive intestinal peptide (VIP), an immunosuppressive neuropeptide, following their intravitreal (IVT) injection in normal rats. METHODS: Healthy seven- to eight-week-old Lewis male rats were injected into the vitreous with empty rhodamine-conjugated liposomes (Rh-Lip) or with VIP-loaded Rh-Lip (VIP-Rh-Lip; 50 mM of lipids with an encapsulation efficiency of 3.0+/-0.4 mmol VIP/mol lipids). Twenty-four h after IVT injection, the eyes, the cervical, mesenteric, and inguinal lymph nodes (LN), and spleen were collected. The phenotype and distribution of cells internalizing Rh-Lip and VIP-Rh-Lip were studied. Determination of VIP expression in ocular tissues and lymphoid organs and interactions with T cells in cervical LN was performed on whole mounted tissues and frozen tissue sections by immunofluorescence and confocal microscopy. RESULTS: In the eye, 24 h following IVT injection, fluorescent liposomes (Rh-Lip and VIP-Rh-Lip) were detected mainly in the posterior segment of the eye (vitreous, inner layer of the retina) and to a lesser extent at the level of the iris root and ciliary body. Liposomes were internalized by activated retinal Müller glial cells, ocular tissue resident macrophages, and rare infiltrating activated macrophages. In addition, fluorescent liposomes were found in the episclera and conjunctiva where free VIP expression was also detected. In lymphoid organs, Rh-Lip and VIP-Rh-Lip were distributed almost exclusively in the cervical lymph nodes (LN) with only a few Rh-Lip-positive cells detected in the spleen and mesenteric LN and none in the inguinal LN. In the cervical LN, Rh-Lip were internalized by resident ED3-positive macrophages adjacent to CD4 and CD8-positive T lymphocytes. Some of these T lymphocytes in close contact with macrophages containing VIP-Rh-Lip expressed VIP. CONCLUSIONS: Liposomes are specifically internalized by retinal Müller glial cells and resident macrophages in the eye. A limited passage of fluorescent liposomes from the vitreous to the spleen via the conventional outflow pathway and the venous circulation was detected. The majority of fluorescent liposomes deposited in the conjunctiva following IVT injection reached the subcapsular sinus of the cervical LN via conjuntival lymphatics. In the cervical LN, Rh-Lip were internalized by resident subcapsular sinus macrophages adjacent to T lymphocytes. Detection of VIP in both macrophages and T cells in cervical LN suggests that IVT injection of VIP-Rh-Lip may increase ocular immune privilege by modulating the loco-regional immune environment. In conclusion, our observations suggest that IVT injection of VIP-loaded liposomes is a promising therapeutic strategy to dampen ocular inflammation by modulating macrophage and T cell activation mainly in the loco-regional immune system.

Ocular transfer of retinal glial cells transduced ex vivo with adenovirus expressing viral IL-10 or CTLA4-Ig inhibits experimental autoimmune uveoretinitis.

Gene transfer using immunomodulatory molecules is a promising tool for in vivo regulation of immune responses. Experimental autoimmune uveitis (EAU), which serves as a model for human ocular inflammation, is induced by systemic immunization with autoantigens, but its expression is restricted to the eye. Previously, we reported protection of rodents against EAU by intravenous or/and periocular injection of vIL-10-expressing adenovirus. Here, the expression of vIL-10 was targeted into the rat Lewis eye, by intravitreal injection of either the free virus or ex vivo transfected retinal Müller glial cells (RMG-vIL-10). As shown using GFP-expressing adenovirus, a longer expression of transgene was observed in the eye after transfer of transfected syngeneic RMG cells than was seen after injection of free virus. Intravitreal injection of RMG-vIL-10 led to significant decrease in ocular pathological manifestations, compared to control RMG cells. This was observed when cells were injected simultaneously with autoantigen, but also after a delayed administration of transfected cells. Finally, injection of RMG cells transfected with adenovirus expressing CTLA4 had a strongly protective effect. In conclusion, inhibition of antigen presentation at the site of expression of the autoimmune disorders represents an attractive alternative to treat ocular inflammation, and the transfer of ex vivo genetically modified cells provides a promising method to target the factor of interest into the eye.

Inhibition of experimental autoimmune uveoretinitis by systemic and subconjunctival adenovirus-mediated transfer of the viral IL-10 gene.

Pathological ocular manifestations result from a dysregulation in the balance between proinflammatory type 1 cytokines and regulatory type 2 cytokines. Interleukin-10 (IL-10) is an anti-inflammatory cytokine with potent immunosuppressive effects. We have examined the efficiency of viral IL-10 adenovirus (Ad-vIL-10)-mediated gene transfer on experimental autoimmune uveoretinitis (EAU) induced in mice and rats by purified retinal autoantigens, respectively, interphotoreceptor binding protein (IRBP) and S-antigen (S-Ag). B10-A mice that received a single unilateral injection of Ad-vIL-10 in the retro-orbital sinus venosus performed 1 day before immunization with IRBP in the footpads showed high levels of circulating vIL-10 in their sera and a significant reduction in pathological ocular manifestations. Lower levels of IFN-gamma and IL-2 were found in cellular supernatants from IRBP-stimulated splenic cells in these treated mice. The local effect on ocular disease of vIL-10 was neutralized completely by injection of a monoclonal anti-vIL-10 antibody, demonstrating the specificity of the treatment. To determine whether the transfer of the vIL-10 gene within the periocular tissues of the eye could prevent acute EAU, a subconjunctival injection of Ad-vIL-10 was performed in Lewis rats simultaneously with S-antigen in the footpads. This injection determined in situ vIL-10 expression with very low circulating vIL-10 and led to a significant reduction of EAU without affecting the systemic immune response. The present results suggest that Ad-mediated gene transfer resulting in systemic and local expression of vIL-10 provide a promising approach for the treatment of uveitis.

The effects of intraocular injection of interleukin-13 on endotoxin-induced uveitis in rats.

PURPOSE: Interleukin (IL)-13 is a strong immunomodulatory cytokine that inhibits macrophages from secreting proinflammatory mediators. This study was conducted to investigate the effect of intraocular injection of IL-13 on the development of endotoxin-induced uveitis (EIU) in the Lewis rat. METHODS: One injection into the anterior chamber of recombinant human IL-13 (6 ng in 10 microl saline) was performed either simultaneously with a single injection of lipopolysaccharide (LPS) from Salmonella typhimurium into the footpad or 6 hours before the IL-13 injection. EIU was evaluated by slit lamp examination at 6, 16, and 24 hours after LPS injection. Counts of inflammatory cells were performed on cryostat sections after specific immunostaining. Anterior chamber paracentesis was performed, and kinetic analysis of the IL-13 injected in the anterior chamber was performed by ELISA. Cytokine and chemokine gene expression in the iris-ciliary body and the retina was evaluated by reverse transcription-polymerase chain reaction. RESULTS: A significant inhibition of ocular inflammation was observed in IL-13-treated rats at 16 and 24 hours after LPS injection. Unilateral injection of IL-13 inhibited EIU only in the injected eye. High levels of IL-13 were detected in the aqueous humor at 2 hours after local IL-13 injection to remain high up to 18 hours. In contrast, IL-13 was not detected in the corresponding sera. Quantitative analysis of inflammatory cells in ocular tissues showed a significant decrease in OX-42(+) cells (microglia, activated macrophages, dendritic cells, and polymorphonuclear leukocytes) and ED1(+) cells (monocytes-macrophages and dendritic cells) in treated rats. A decreased expression of TNF-alpha, IL-1 beta, IL-6, monocyte chemoattractant protein (MCP)-1, and macrophage inflammatory protein (MIP)-2 mRNAs was observed in the iris-ciliary body and the retina from IL-13-treated rats, whereas IFN-gamma was upregulated in the iris-ciliary body. CONCLUSIONS: Injection of IL-13 into the anterior chamber may inhibit the ocular inflammation induced by LPS injection by reducing intraocular cytokine and chemokine mRNA expression in ocular tissues.

Spontaneous retinopathy in HLA-A29 transgenic mice.

Humans who have inherited the class I major histocompatibility allele HLA-A29 have a markedly increased relative risk of developing the eye disease termed birdshot chorioretinopathy. This disease affecting adults is characterized by symmetrically scattered, small, cream-colored spots in the fundus associated with retinal vasculopathy and inflammatory signs causing damage to the ocular structures, leading regularly to visual loss. To investigate the role of HLA-A29 in this disease, we introduced the HLA-A29 gene into mice. Aging HLA-A29 transgenic mice spontaneously developed retinopathy, showing a striking resemblance to the HLA-A29-associated chorioretinopathy. These results strongly suggest that HLA-A29 is involved in the pathogenesis of this disease. Elucidation of the role of HLA-A29 should be assisted by this transgenic model.

Delayed onset and decreased severity of experimental autoimmune uveoretinitis in mice lacking nitric oxide synthase type 2.

To investigate the role of nitric oxide (NO), produced by the inducible form of NO synthase (NOS-2) in the development of experimental autoimmune uveoretinitis (EAU), we immunized C57BL/6x129Sv (H-2(b)) mice carrying a targeted disruption of the gene encoding NOS-2 (NOS-2[-/-]), and wild-type (WT) C57BL/6x129Sv controls with interphotoreceptor retinoid binding protein (IRBP). NOS-2[-/-] mice developed a clinical EAU with delayed onset and decreased severity compared to WT controls. The ocular tissues from WT mice contained activated F4/80 macrophages with NOS-2 expression and retinal destruction whereas less intense EAU was detected in NOS-2[-/-] mice. The expression of NOS-2 mRNA was detected in the retina at the peak of EAU in WT. Analysis of cytokine production in the spleen from NOS-2[-/-] mice by RT-PCR showed high levels of IL-10 mRNA. Our results demonstrate that NO is clearly involved in EAU and may be important for the regulation of immune responses through the regulation of IL-10.

Inhibition of endotoxin-induced uveitis and potentiation of local TNF-alpha and interleukin-6 mRNA expression by interleukin-13.

PURPOSE: To investigate the effect of systemic injections of interleukin (IL)-13 on the development of endotoxin-induced uveitis (EIU) in the rat. METHODS: EIU was induced in Lewis rats by a single footpad injection of lipopolysaccharide (LPS; 350 microg/kg) from Salmonella typhimurium. Rats were treated with a subcutaneous injection in the back of recombinant human IL-13 (50 microg/kg in 0.2 ml of saline) performed 30 minutes before LPS injection and 6 and 10 hours afterward. At 23 hours after LPS injection, EIU was evaluated by slit-lamp examination and by counts of inflammatory cells on cryostat sections after specific immunostaining. The expression of nitric oxide synthase (NOS)-II in ocular tissues was determined by dual immunofluorescent staining and the release of nitrite in aqueous humor by Griess reaction. Cytokine gene expression in the iris/ciliary body, choroid, and retina was evaluated by reverse transcription-polymerase chain reaction. RESULTS: At 24 hours after LPS injection, significant clinical inhibition of ocular inflammation and fibrin deposition in the eye was observed in IL-13-treated rats. Quantitative analysis of ocular tissues revealed a significant decrease of OX42+ cells (microglia, activated macrophages, dendritic cells, and polymorphonuclear leukocytes) and ED-1+ cells (monocytes/macrophages and dendritic cells). No effect on ED2+ cells (resident tissue macrophages) was found. Treatment with IL-13 decreased nitrite levels in aqueous humor and enhanced the expression of tumor necrosis factor-alpha (TNF-alpha) and IL-6 mRNA in ocular tissues. CONCLUSIONS: Interleukin-13 treatment inhibits LPS-induced ocular inflammation with inhibition of nitrite release and increased TNF and IL-6 production in the eye. These results confirm the role of the NO pathway in the pathogenesis of EIU and suggest the involvement of TNF and IL-6 in the downregulation of ocular inflammation.

Effect of macrophage depletion by liposomes containing dichloromethylene-diphosphonate on endotoxin-induced uveitis.

Footpad injection of lipopolysaccharide (LPS) from Salmonella typhimurium in Lewis rats induces an acute anterior and posterior endotoxin-induced uveitis (EIU). To investigate the role of macrophages in the pathogenesis of EIU, we eliminated macrophages by means of liposomes containing dichloromethylene-diphosphonate (Cl2MDP), a drug which depletes macrophages but not other immunocompetent cells. Intravenous injection of CL2MDP-liposomes clearly inhibited clinical and histological manifestations of uveitis in the anterior segment of the eye (iris/ciliary body) and reduced TNF level in aqueous humor. Specific immunostaining showed that CL2MDP-liposome injections decreased the number of ED2 + resident macrophages in the iris/ciliary body and the choroid. After LPS injection, CL2MDP-liposome treatment reduced the density of infiltrating ED1 + cells (mainly monocytes/macrophages) in the iris/ciliary body but not in the choroid; little or no effect was detected on the OX42 + cellular infiltration (mainly polymorphonuclear leukocytes). The inflammatory cellular infiltration of the retina was not modified by the treatment. These findings suggest that macrophages play a key role in the pathogenesis of ocular inflammation.

Differential tumor necrosis factor and nitric oxide production in retinal Müller glial cells from C3H/HeN and C3H/HeJ mice.

Tumor necrosis factor (TNF) and nitric oxide (NO) have been shown to play a role in the pathogenesis of endotoxin-induced uveitis (EIU) in rats. Susceptibility to develop EIU in vivo is correlated with the extent of TNF production by retinal Müller glial cells (RMG). Moreover, RMG cells from the susceptible Lewis rat strain synthesize high amounts of nitrite under in vitro stimulation. Variations in susceptibility to endotoxin are observed among mice strains: C3H/HeN mice are known to be susceptible to develop EIU while C3H/HeJ are refractory. We show here that treatment of RMG cells from both strains with LPS + IFN-gamma does not induce TNF-synthesis in culture supernatants but produces high amounts of NO only in the supernatants from activated C3H/HeN RMG cells. The addition of TNF in the culture medium containing LPS/IFN-gamma further increases nitrite production in C3H/HeN RMG cells and allows the synthesis of low levels of nitrite in C3H/HeJ RMG cells. Addition of a specific NO synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA), blocks NO release. We have previously shown that intraperitoneal injections of the NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) which inhibited nitrite and TNF release in the ocular media reduced EIU in rat. We conclude here that the in vivo susceptibility to develop EIU in mice is correlated with the extent of in vitro nitrite production by RMG cells confirming the implication of NO in the induction of ocular inflammation. The low level of retinal inflammation observed during EIU in C3H/HeN mice compared to rats could be related to the absence of TNF production by RMG cells.

NGF involvement in ocular inflammation: secretion by rat resident retinal cells.

Nerve growth factor (NGF) has been reported to be involved in immune and inflammatory reactions. We provide evidence that NGF may play a role in ocular immune responses. Experimental autoimmune uveoretinitis (EAU) causes ocular inflammation in susceptible (Lewis, Lew x Brown-Norway (BN) F1 hybrid) but not in resistant or poorly susceptible BN and Long Evans rat strains. We examined NGF production by two resident ocular cell types, retinal Müller glia (RMG) and retinal pigmented epithelium (RPE). Interferon-gamma (IFN-gamma) or lipopolysaccharide (LPS) alone had no effect on NGF production while combined treatment with IFN-gamma and LPS strongly stimulated NGF secretion by both RMG and RPE cells. Furthermore, NGF secretion correlated with the degree of susceptibility to EAU of the different rat strains. RMG and RPE cells isolated from susceptible rats secrete high NGF levels while cells from resistant rats secrete low NGF levels.

Differential tumor necrosis factor expression by resident retinal cells from experimental uveitis-susceptible and -resistant rat strains.

Experimental autoimmune uveoretinitis (EAU) and endotoxin-induced uveitis (EIU), models for human ocular immunopathological syndromes, result in ocular inflammation in susceptible, but not in resistant rat strains. Moreover rapid photoreceptor degeneration occurs in susceptible rats developing EAU. In order to see whether differences in local ocular immune regulation may account for changes in resistance or susceptibility, we have examined the in vitro production of the cytotoxic cytokine tumor necrosis factor (TNF) by two resident ocular cell types, retinal Müller glia (RMG) and retinal pigmented epithelium (RPE). These cells were isolated and cultured in vitro from Lewis (Lew) (highly susceptible), Lew x Brown-Norway (BN) F1 hybrid (susceptible), BN and Long-Evans (LE) (resistant or poorly susceptible) rats. Constitutive production of the cytokine TNF, or its liberation in response to either interferon-gamma (IFN-gamma) or lipopolysaccharide (LPS) alone, was very low in RMG and RPE cells, irrespective of the strain. It was strongly induced by combined treatment with IFN-gamma and LPS in Lew RMG and RPE cells (mean values of 140 and 150 pg/10(5) cells, respectively) and in Lew x BN F1 RMG and RPE cells (mean values of 125 and 190 pg/10(5) cells, respectively), much less so from BN RMG and RPE cells (30 and 20 pg/10(5) cells, respectively) and remained undetectable in LE RMG and RPE cells. Hence susceptibility to EAU and EIU in vivo is correlated with the extent of TNF production by these two cell types under in vitro conditions, which may play a key role in initiating or perpetuating local immune responses.

Elevation of serum M-CSF concentrations during pregnancy and ovarian hyperstimulation.

Macrophage colony stimulating factor (CSF-1 or M-CSF) is involved in haemopoiesis and probably in mouse gestation. Sexual steroids induce its production by uterine glandular epithelial cells and its receptor (product of the protooncogene C-FMS) is expressed on placental trophoblastic cells. We measured M-CSF serum levels in 119 pregnant women and in eight women undergoing ovarian hyperstimulation for in vitro fertilization. M-CSF increased early (4-8 weeks) and progressively during gestation. Its rapid elevation during the course of ovarian hyperstimulation suggests that its synthesis is probably induced by sexual steroids. This locally produced M-CSF could play a role in human pregnancy and in the pathogenesis of thrombocytopenias observed during pregnancy.

Collagen gel cultures for detection of spared hematopoietic progenitors in Asta Z 7557 purged human marrows.

Asta-Z 7557, an in vitro active metabolite of cyclophosphamide, is used for human bone marrow purging in acute leukemias and solid tumors since it is more highly toxic to tumor than normal hematopoietic clonogenic cells. However, doses higher than 80 microM totally inhibit the growth of hematopoietic progenitors in semisolid assays, despite preservation of marrow repopulating ability in vivo. This discrepancy complicates assessment of the functional value of purged grafts. In 11 patients undergoing autologous bone marrow transplantation with 100 microM Asta-Z purged marrow, we investigated the advantages of the collagen gel culture system for detection of spared hematopoietic progenitors. This technique provides a suitable and convenient assay as compared with results with agar. In nine of 11 samples after 14 or 21 days of incubation, up to 100 colonies were observed, (64% monocytic, 27% granulocytic). Day-14 granulocytic colonies were mostly immature, suggesting that they derived from early CFU-GM or pre-CFU-GM. This development of early progenitors could account for the better sensitivity of this technique compared with agar or methylcellulose systems. The mechanism involved as well as the correlation between colony growth in collagen and clinical hematopoietic recovery is also considered.

Gastrotropin: not an enterooxyntin but a member of a family of cytoplasmic hydrophobic ligand binding proteins.

Gastrotropin, a peptide initially isolated from porcine intestinal extracts, has been proposed to be an enterooxyntin. We have isolated a full length gastrotropin cDNA from a hog small intestinal lambda gt11 library. No evidence of co-translational translocation or processing of the encoded 127-residue protein could be demonstrated using an in vitro transcription/translation/microsomal processing assay. Comparative sequence analyses indicate that gastrotropin is a new member of the family of cytoplasmic hydrophobic ligand proteins. Analysis of the distribution of gastrotropin in nine adult Sprague-Dawley rat tissues revealed that the gene is expressed in small intestine but not in stomach, liver, heart, skeletal muscle, lung, kidney, adrenals, or brain. Bioactivity studies demonstrated that neither gastrotropin nor a carboxyl-terminally amidated tridecapeptide fragment deduced from the cDNA sequence influence acid secretory activity in rats with gastric fistulas or in isolated canine gastric parietal cells. Together these data suggest that gastrotropin is not likely to be secreted as a hormone or to function as an enterooxyntin. Moreover, it appears that gastrotropin represents one of several members of the family of hydrophobic ligand binding proteins that are expressed in the small intestine.

Blood erythroid progenitors (CFU-E and BFU-E) in acute lymphoblastic leukemias.

Circulating erythroid progenitors from 14 patients with acute lymphoblastic leukemia (ALL) and from 8 healthy subjects were studied in culture to determine the frequency and size of CFU-E- and BFU-E-derived colonies. Cells were cultured in a plasma clot system, and hemoglobinized colonies identified by diaminobenzidine reaction. The numbers of CFU-E and BFU-E per milliliter of peripheral blood were greatly increased in 10 patients when compared to controls. In 13 patients, the size distribution of BFU-E-derived colonies, analyzed by counting the number of subunits in each colony, was also found to differ significantly from controls, with a large excess of small colonies and a low percentage or a total lack of large colonies. This abnormal BFU-E size distribution was partially corrected, in the 5 patients tested, by the addition to the culture medium of 10% phytohemagglutinin-leukocyte-conditioned medium (PHA-LCM). Bone marrow crowding out of the normal progenitors, as well as disturbances in the cellular interactions involved in their normal development, most likely explain these results and these factors could be implicated in the frequent pancytopenia of ALL.

Presynaptic inhibitory effects of sotalol, propranolol, and acebutolol on noradrenaline release upon cardiac sympathetic nerve stimulation in anesthetized dogs.

Effect of sotalol (STL) was compared with that of (+/-)-propranolol, (+)-propranolol (PPL), and acebutolol (ABL) on noradrenaline (NA) release as measured in coronary sinus (CS) blood during postganglionic stimulation (2 Hz, 30 s) of the left cardiac sympathetic nerves in anesthetized dogs. In control dogs receiving saline, increasing responses of CS-NA concentration, mean CS blood flow, and CS-NA output to repetitive stimulation were relatively stable throughout a given experimental period. Both STL (1,2.5, and 5 mg/kg, i.v.) and (+/-)-PPL (0.5 and 2.5 mg/kg, i.v.) diminished the increased CS-NA concentration by approximately 35 (P less than 0.05) to 60% (P less than 0.01) in a dose-dependent fashion. However, (+)-PPL (0.02-2.5 mg/kg, i.v.) and ABL (0.5-5 mg/kg, i.v.) did not significantly alter the increasing response of CS-NA concentration upon stimulation. STL, (+/-)-PPL, and ABL markedly inhibited the CS blood flow response to stimulation at all doses tested, while (+)-PPL did not significantly diminish the flow response even at the highest dose tested. Consequently, CS-NA output decreased significantly (p less than 0.01) in the presence of STL, (+/-)-PPL, and ABL at all doses tested but not with (+)-PPL at any dose tested. The inhibitory effect of STL and (+/-)-PPL on the increasing response of CS-NA concentration upon stimulation could be related to their beta-blocking effect, which exerts presumably on postulated presynaptic beta-adrenoceptors, as (+)-PPL did not at all diminish the response.(ABSTRACT TRUNCATED AT 250 WORDS)