Increased expression of phospholipase D1 in the sciatic nerve of rats with experimental autoimmune neuritis

Phospholipase D1 (PLD1) expression in the sciatic nerve was studied in induced experimental autoimmune neuritis (EAN) in Lewis rats. PLD1 immunoreactivity was seen in some Schwann cells in the sciatic nerves of normal rats. In parallel with the progression of EAN, PLD1-positive Schwann cells significantly increased in number and showed intense immunoreactivity. PLD1 was also detected in some ED1+ macrophages in EAN lesions. These results suggest that PLD1 in macrophages and Schwann cells plays an important role in the activation of these cells in the pathogenesis of EAN, an animal model of human peripheral demyelinating disease.

Increased expression of phospholipase D1 in the spinal cords of rats with experimental autoimmune encephalomyelitis

Phospholipase D1 (PLD1) expression was studied in the central nervous system (CNS) under the condition of induced experimental autoimmune encephalomyelitis (EAE) in Lewis rats. After inducing EAE, the expression of PLD1 was analyzed by Western blot and immunohistochemistry. Western blot analysis showed that expression of the isozymes PLD1 significantly increased in the spinal cord at the peak stage of EAE, and declined thereafter. Immunohistochemistry showed that PLD1-positive cells increased in number in EAE lesions, which consisted mainly of ED1-positive macrophages and glial fibrillary acidic protein-positive astrocytes. In contrast, PLD1 was only weakly expressed in some spinal cord astrocytes in control rats. These results suggest that PLD1 is increased in autoimmune CNS inflammation, and possibly involved in the activation of macrophages and astrocytes in EAE lesions.

Expression of telomerase subunits in normal and neoplastic prostate epithelial cells isolated by laser capture microdissection

BACKGROUND

Vertebrates have special structures at the ends of their chromosomes, known as telomeres, which may provide the chromosomes with stability and protect them from exonucleolytic degradation. The shortening of telomeric DNA with each cell division may lead to cell cycle arrest and/or apoptosis of a normal human somatic cell. Telomerase, an RNA-dependent DNA polymerase, elongates the 3'-ends of telomeric DNA. Thus, the presence of telomerase activity may reflect a cell's potential immortal state. The telomerase complex is comprised of several subunits. In the current study, the authors describe the use of laser capture microdissection (LCM) to procure pure matched tumor and normal cell populations from histologic sections and to determine the expression of telomerase subunits in these purified samples.

METHODS

Pure matched tumor and normal prostate epithelial cells were procured by LCM using fresh frozen tissue samples obtained from patients undergoing radical prostatectomy. RNA was extracted from LCM captured cells, and the subunits for telomerase were assayed by reverse transcriptase-polymerase chain reaction.

RESULTS

In 18 samples that were captured with LCM, only the catalytic subunit of telomerase, or hTERT, was found to be discriminatory between tumor cells (17 of 18 specimens, 94.4%) and nontumor cells (none of 18 specimens). TP1, a protein that has been shown to be associated with telomerase activity, was expressed in 3 of 18 normal cells (16.7%) and 15 of 18 tumor cells (83.3%). The RNA subunit of telomerase, or hTR, was expressed in 10 of 18 normal cells (55.6%) and 18 of 18 tumor cells (100%). There was no apparent correlation between telomerase subunit(s) expression and Gleason sum score.

CONCLUSIONS

Molecular analyses of LCM cells from prostate carcinoma patient samples demonstrated transcriptional up-regulation of all telomerase subunits in the prostatic epithelium. However, only the catalytic subunit of telomerase, hTERT, was found to be discriminatory between neoplastic versus normal cells (94.4% vs. 0%). This finding suggests that the hTERT subunit may be a useful marker for the detection of prostate carcinoma and/or a potential target for therapy.

Skin-sparing mastectomy with sentinel lymph node dissection: less is more

Skin-sparing mastectomy is an emerging technique useful for patients with early-stage breast cancer who are not candidates for breast conservation surgery and are candidates for immediate plastic surgery reconstruction of the breast. Coupled with sentinel node surgery to assess lymph node status, the goal of this technique is to achieve maximal breast and axillary tissue conservation without compromising thorough tumor resection.

Psoas hitch ureteral reimplantation in adults--analysis of a modified technique and timing of repair

OBJECTIVES

The psoas hitch ureteral reimplantation technique has been used with great success to bridge defects in ureteral length due to injury or planned resection. Several surgical principles have been historically stressed when performing this procedure, including adequate mobilization of the bladder, fixation of the bladder to the psoas tendon before reimplantation, the use of a submucosal nonrefluxing-type ureteral anastomosis, and a 6-week delay before attempting repair after a surgical injury. We retrospectively reviewed patients who underwent ureteroneocystostomy with a psoas hitch, evaluated the relevance of these principles, and describe a modification of the technique.

METHODS

All patients undergoing psoas hitch ureteral reimplantation were reviewed. The indications, complications, and long-term outcomes were assessed.

RESULTS

Between 1989 and 1999, 24 patients underwent psoas hitch reimplantation at our institution. The indications were operative injury in 11, planned surgical resection during nonurologic pelvic surgery in 4, cancer in 4, stricture in 4, and trauma in 1. Refluxing-type ureteral anastomoses were performed in 17 cases. One case of postoperative urosepsis occurred. A delayed repair after operative injury did not improve the operative time or overall morbidity. No cases of chronic flank pain, recurrent pyelonephritis, persistent severe hydronephrosis, or compromised renal function, as measured by a change in baseline serum creatinine level, occurred. No patient required reoperation for either early or delayed complications or failure of the repair at a follow-up of 1 to 122 months (mean 32.75).

CONCLUSIONS

Psoas hitch ureteral reimplantation is an effective means of treating defects in ureteral length. Immediate repair may be safely undertaken as soon as the ureteral injury is recognized. Long-term sequelae are unusual in adults, even when using refluxing-type ureteral anastomoses.

Melatonin ameliorates autoimmune encephalomyelitis through suppression of intercellular adhesion molecule-1

Melatonin (N-acetyl-5-methoxytryptamine), a pineal neurohormone, is a hydroxyl radical scavenger and antioxidant, and plays an important role in the immune system. We studied the effect of exogenous melatonin on the pathogenesis of experimental autoimmune encephalomyelitis (EAE). EAE was induced in Lewis rats by immunization with rat spinal cord homogenates. Subsequent oral administration of melatonin at 5 mg/kg significantly reduced the clinical severity of EAE paralysis compared with administration of the vehicle alone (p<0.01). Infiltration of ED1+ macrophages and CD4+ T cells into spinal cords occurred both in the absence and presence of melatonin treatment, but melatonin-treated rats had less spinal cord infiltration of inflammatory cells than did the control group. ICAM-1 immunoreactivity in the blood vessels of EAE lesions was decreased in melatonin-treated rats compared to vehicle-treated rats. These findings suggest that exogenous melatonin ameliorates EAE via a mechanism involving reduced expression of ICAM-1 and lymphocyte function associated antigen-1a in autoimmune target organs.

Pertussis toxin-induced hyperacute autoimmune encephalomyelitis in Lewis rats is correlated with increased expression of inducible nitric oxide synthase and tumor necrosis factor alpha

The involvement of inducible nitric oxide synthase (iNOS) and tumor necrosis factor alpha (TNF-alpha), which have diverse roles in the progression of autoimmune disease models, was studied in pertussis toxin (PT)-induced hyperacute experimental autoimmune encephalomyelitis (EAE) in Lewis rats. The expression of TNF-alpha mRNA (increased 5-fold, P<0.01) and iNOS protein (3-fold, P<0.01) was much greater in the spinal cords with PT(+) EAE at the peak stage of EAE than in those with PT(-) EAE, as shown by competitive PCR and Western blot analysis, respectively. Immunohistochemistry showed that the majority of ED1-positive macrophages in EAE lesions contained iNOS, and that there were many more iNOS-positive cells in the CNS lesions of PT(+) rats than in those of PT(-) rats. These findings suggest that PT-induced hyperacute EAE is partly mediated by the enhanced expression of iNOS and TNF-alpha in the early stages of rat EAE.

A mutant cholera toxin B subunit that binds GM1- ganglioside but lacks immunomodulatory or toxic activity

GM1-ganglioside receptor binding by the B subunit of cholera toxin (CtxB) is widely accepted to initiate toxin action by triggering uptake and delivery of the toxin A subunit into cells. More recently, GM1 binding by isolated CtxB, or the related B subunit of Escherichia coli heat-labile enterotoxin (EtxB), has been found to modulate leukocyte function, resulting in the down-regulation of proinflammatory immune responses that cause autoimmune disorders such as rheumatoid arthritis and diabetes. Here, we demonstrate that GM1 binding, contrary to expectation, is not sufficient to initiate toxin action. We report the engineering and crystallographic structure of a mutant cholera toxin, with a His to Ala substitution in the B subunit at position 57. Whereas the mutant retained pentameric stability and high affinity binding to GM1-ganglioside, it had lost its immunomodulatory activity and, when part of the holotoxin complex, exhibited ablated toxicity. The implications of these findings on the mode of action of cholera toxin are discussed.

Intrathecal administration of endothelin-1 receptor antagonist ameliorates autoimmune encephalomyelitis in Lewis rats

The role of endothelin-1 (ET-1) in the development of experimental autoimmune encephalomyelitis (EAE) was studied by the blocking the action of ET-1 with a receptor antagonist, BQ-123. Intrathecal administration of BQ-123 significantly ameliorated EAE progression at the peak stage of EAE (p<0.05). By immunohistochemistry, ED-1-positive macrophages in EAE lesions were identified as major producers of ET-1, whereas the immunoreactivity of ET-1 on brain cells, such as astrocytes, was dramatically increased in accordance with the progression of EAE. This study points to a putative pro-1nflammatory role for ET-1 in the pathogenesis of EAE. One possible application for the ET-1 receptor antagonist might be helpful in the therapy of autoimmune neurological disorders.

Public-private partnerships in health care for developing countries: a new paradigm for change

The shift in traditional corporate philanthropy policy and practices from one of objective giving to strategic investing is discussed along with the positive impact of these changes as realized through a social awareness and the emerging new paradigm of public private partnerships. Examples of corporate support with focus on a case study concerning HIV/AIDS in Africa are presented within the context of lessons learned. These examples illustrate how public and private sectors working together, can maximize the potential philanthropic endeavor. Using strategically directed, yet humanitarian and culturally sensitive efforts, managed care organizations may find the concepts and negotiations inherent to philanthropic partnerships a familiar setting, and would therefore be suitable candidates to engage in public-private partnerships.

Exploration of the GM1 receptor-binding site of heat-labile enterotoxin and cholera toxin by phenyl-ring-containing galactose derivatives

Cholera toxin (CT) and the closely related heat-labile enterotoxin of Escherichia coli (LT) are responsible for numerous cases of diarrhea worldwide, leading to considerable morbidity and mortality. The B subunits of these heterohexameric AB(5) toxins form a pentameric arrangement which is responsible for binding to the receptor GM1 of the target epithelial cells of the host. Blocking these B pentamer-receptor interactions forms an avenue for therapeutic intervention. Here, the structural characterization of potential receptor-blocking compounds are described based on the previously identified inhibitor m-nitrophenyl-alpha-D-galactoside (MNPG). The structure of a CTB-MNPG complex confirms that the binding mode of this inhibitor is identical in the two homologous toxins CT and LT and is characterized by a glycosyl linkage geometry that leads to displacement of a well ordered water molecule near the amide group of Gly33 by the O1-substituent of MNPG. This glycosyl geometry is not maintained in the absence of a substituent that can displace this water, as shown by a complex of LTB with p-aminophenyl-alpha-D-galactoside (PAPG). New compounds were synthesized to investigate the feasibility of maintaining the favorable binding interactions exhibited by MNPG while gaining increased affinity through the addition of hydrophobic substituents complementary to either of two hydrophobic regions of the receptor-binding site. The structural characterization of complexes of LTB with two of these compounds, 3-benzylaminocarbonylphenyl-alpha-D-galactoside (BAPG) and 2-phenethyl-7-(2,3-dihydrophthalazine-1,4-dione)-alpha-D-galactoside (PEPG), demonstrates a partial success in this goal. Both compounds exhibit a mixture of binding modes, some of which are presumably influenced by the local packing environment at multiple crystallographically independent binding sites. The terminal phenyl ring of BAPG associates either with the phenyl group of Tyr12 or with the hydrophobic patch formed by Lys34 and Ile58. The latter interaction is also made by the terminal phenyl substituent of PEPG, despite a larger ring system linking the galactose moiety to the terminal phenyl. However, neither BAPG nor PEPG displaces the intended target water molecule. Both of the designed compounds exhibit increased affinity relative to the galactose and to PAPG notwithstanding the failure to displace a bound water, confirming that additional favorable hydrophobic interactions can be gained by extending the starting inhibitor by a hydrophobic tail. The insight gained from these structures should allow the design of additional candidate inhibitors that retain both the glycosyl geometry and water displacement exhibited by MNPG and the favorable hydrophobic interactions exhibited by BAPG and PEPG.

Selection of a high affinity angiogenin-binding peptide from a peptide library displayed on phage coat protein

Although the phage-displayed peptide libraries have been widely used for the biopanning of peptide specific for various types of target molecules, the selected peptides often have affinities too low for practical purposes. In this report, selection of a high affinity peptide ligand specific for human angiogenin is described. We constructed a random dodecapeptide library displayed on the gene III protein of filamentous bacteriophage by use of a phagemid. The peptide insert was flanked by two cysteines to constrain the peptide structure by a disulfide bond. Phages were collected from 1.5 x 10(3) independent transformants. After the library phages were allowed to bind to the human angiogenin coated on a plate, the phages bound to the actin-binding site of angiogenin were selectively eluted with actin. The activity of each phage clone was estimated and three high affinity phage clones were identified. The peptides displayed by the three phage clones were synthesized as fusion proteins with Escherichia coli maltose-binding protein, and used for the quantitative estimation of their affinities. By this procedure, we were able to select a peptide having a dissociation constant of about 60 nM.

Long-lasting adenovirus transgene expression in mice through neonatal intrathymic tolerance induction without the use of immunosuppression

The major barrier to the clinical application of adenovirus gene therapy for diseases that require stable transgene expression is the immunogenicity of recombinant adenovirus, which ordinarily limits the duration of its effects to a period of about 2 weeks. We postulated that tolerance to adenovirus could be induced and transgene expression could be prolonged if T lymphocytes underwent thymic selection in the presence of adenovirus antigens. Mice were inoculated in the thymus with a recombinant adenovirus containing the lacZ marker gene during the neonatal period at a time before T-cell maturation had occurred. When the virus was administered intravenously to these mice in adulthood, they were found to have an impaired adenovirus-specific cytotoxic T-lymphocyte response which allowed prolonged hepatic lacZ expression, for up to 260 days. The ability to achieve unresponsiveness to a recombinant adenovirus after inoculation of the thymus in neonates extends the paradigm of intrathymic tolerance induction. Furthermore, this model will enable the study of stable adenovirus transgene expression in vivo without the use of immunosuppression and ultimately may have clinical utility.

Immunologic barriers to hepatic adenoviral gene therapy for transplantation

Adenoviral gene transfer has potential use to attenuate the immunogenicity of hepatic allografts. However, the clinical application of adenoviral gene therapy is currently impeded by the potent host immune response to the virus that limits the duration of its effects. In these studies, we identify the cellular and humoral immune responses to recombinant adenovirus in the liver of mice and define the immunologic barriers to the successful application of this technology to transplantation. The immunobiology of recombinant adenovirus was studied in mouse liver using vectors containing the lacZ and alkaline phosphatase marker genes. The duration of transgene expression was studied in various immunodeficient mice to determine the mechanism of viral clearance. Adoptive transfer of serum to B lymphocyte deficient mice and neutralizing antibody assays were used to define the antiviral humoral response. Hepatic adenoviral transgene expression was prolonged in animals deficient in CD4+ or CD8+ T cells indicating their importance in viral clearance. Unexpectedly, mice lacking B lymphocytes also had delayed elimination of virus suggesting that B cells play a role in the primary immune response. Effective repeat gene transfer was blocked by adenoviral-specific neutralizing antibody. Therefore, a T lymphocyte response results in viral elimination after a primary intravenous inoculation of recombinant adenovirus and a potent humoral response inhibits effective repeat adenoviral gene transfer. The immunogenicity of the vector must be overcome for adenoviral gene therapy to have therapeutic application for hepatic transplantation.

Gene transfer to the thymus. A means of abrogating the immune response to recombinant adenovirus

OBJECTIVE

The authors investigated whether adenoviral gene transfer to the thymus could be accomplished in vivo and whether immunologic unresponsiveness to recombinant adenovirus could be induced by intrathymic inoculation.

SUMMARY BACKGROUND DATA

A major barrier to the clinical application of adenovirus-mediated gene therapy for diseases requiring long-lasting gene expression is the immunogenicity of adenoviral vectors, which limits the duration of its effects. In other experimental models, intrathymic inoculation of foreign proteins or cells has proven to be an effective means to induce immunologic tolerance.

METHODS

The efficiency of gene transfer to the mouse thymus after direct inoculation of recombinant adenovirus was compared with that of several other vectors. Animals inoculated with adenovirus-infected pancreatic islets into the thymus were tested for unresponsiveness to the virus with a subsequent challenge of adenovirus administered into the liver by intravenous injection.

RESULTS

Adenovirus accomplished highly efficient gene transfer to the thymus, unlike plasmid DNA, DNA-liposome complexes, retrovirus, and adeno-associated virus. Adenoviral transgene expression was transient in the thymus of immunocompetent mice but persistent in CD8+ T-cell-deficient and severe combined immunodeficiency (SCID) mice, implicating the role of cytotoxic T lymphocytes in viral clearance. Intrathymic transplantation of syngeneic pancreatic islet cells infected with adenovirus impaired the normal antiviral cytotoxic T-lymphocyte response and prolonged hepatic transgene expression after an intravenous challenge with adenovirus.

CONCLUSIONS

Recombinant adenovirus accomplishes highly efficient gene transfer to the thymus in vivo. Intrathymic inoculation of adenovirus-infected islets can be used to induce immunologic unresponsiveness to the adenoviral vector and, potentially, to other proteins that it might be engineered to encode.

Judgments of "normal" and "problem" alcohol use as related to reported alcohol consumption

We obtained alcohol use data and judgments of individual ("What do you think?") and cultural ("What do people in general think?") norms for normal and problem quantity and frequency of alcohol use, as well as ratings of whether particular alcohol-related behaviors indicated a drinking problem, from 928 adult respondents who were members of Hawaii's five major racial/ethnic groups [Chinese, European (Caucasian), Filipino, Hawaiian/Part-Hawaiian, and Japanese ancestry]. As compared with older survey data (but consonant with recent survey data), Hawaiians have substantially increased in alcohol use, as have Filipinos (if they drink at all; a high proportion are abstainers), and to a lesser extent, Japanese. Chinese remain very low in alcohol use, while Caucasians have relatively decreased in use. Alcohol use norms (especially of own judged normal use) vary across sexes and ethnic groups and are predictors of consumption both within and across groups. Family resemblances are substantial with regard to alcohol use category (present users, former drinkers, abstainers). Among present users, family resemblances are often significant with regard to amount used; resemblances are more substantial between mothers and offspring than between spouses or between fathers and offspring. There were small but significant ethnic group differences in the number of specific behaviors judged to be indicative of a drinking problem, with the groups reporting the highest mean alcohol consumption (Caucasians and Hawaiians/Part Hawaiians) also indicating more behaviors, particularly pathological as opposed to celebratory behaviors, as being problematic.(ABSTRACT TRUNCATED AT 250 WORDS)