Metenkephalin in seminal plasma of infertile men

BACKGROUND

Enkephalin is one of the opioids, which is expressed widely in reproductive organs. However, the function of enkephalin in male reproduction is not completely understood. The effect of metenkephalin on sperm motility remains especially controversial. In this study we examined the level of metenkephalin in seminal plasma from men with normal sperm production and patients with asthenospermia, oligospermia, and azoospermia to investigate the role of metenkephalin in seminal plasma on sperm function. We also investigated the effect of metenkephalin on sperm motility in vitro.

METHODS

Sixty nine infertile patients (31 oligospermic, 21 asthenospermic, and 17 azoospermic) were included in this study. The level of metenkephalin in seminal plasma of these men was measured and the effect of the peptide on the motility of human sperm was examined in vitro. Seventeen men with normal seminograms were a control group.

RESULTS

The level of metenkephalin in the seminal plasma of semen from asthenospermic men was significantly lower than that from the controls (P < 0.05). No significant correlations between the level of metenkephalin and the mean pathing or progressive velocity of sperm, or serum hormone levels were observed. In the in vitro study, which used semen from the controls, treatment of sperm with metenkephalin (50-200 pg/mL) maintained sperm motility for 4 hours. On the other hand, motility of sperm incubated without metenkephalin began to decrease at 3 hours. Metenkephalin levels of 50 pg/ mL in seminal plasma is considered to be necessary for maintaining sperm motility.

CONCLUSION

These results suggest that metenkephalin in seminal plasma is an important clue in the investigation of decreased sperm motility.

Hyperprolactinaemia among infertile patients and its effect on sperm functions

The effects of hyperprolactinaemia on sperm function were investigated in 264 men with oligozoo-, asthenozoo-, or teratozoospermia and who were attending a male infertility clinic. None of the patients exhibited galactorrhea or complained of impotence. There was no correlation between abnormal values in spermiogram and hyperprolactinaemia. After multiple measurements of serum prolactin concentration, 15 cases (5.7%) were diagnosed as hyperprolactinaemic (> or = 10 ng ml-1). Six of these patients were taking cimetidine and six were taking anti-anxiety drugs. Serum prolactin returned to the normal level after discontinuation of these drugs; thus these 12 cases were considered as drug-induced hyperprolactinaemia. The other three patients were diagnosed as having pituitary microadenomas and received bromocriptine treatment; the serum prolactin levels normalized within 1 month. No changes in sperm concentration, motility or morphology were found after normalization of serum prolactin levels. Sperm fertilizing ability was monitored by the hamster test for 10 months in the three patients with pituitary microadenoma, and no improvement was observed. Results suggest that hyperprolactinaemia, which does not cause symptoms, has little effect on the impairment of sperm functions. Measurement of serum prolactin in infertile men could be justified, however, for early detection of pituitary adenomas.

[An approach to the emergency surgery for arch and/or ascending aortic aneurysm]

The outcome of emergency surgery for the aortic arch aneurysm and/or dissecting aneurysm is worse than that of elective surgery. To decide the future strategy of the emergency surgery for these disease, 11 patients with emergency surgery (= group E: 8 for aortic dissection and 3 for rupture of the aortic arch aneurysm, age; 61 +/- 13 SD) were compared with 12 patients who had elective surgery (= group S: 5 for aortic dissection and 7 for aortic arch aneurysm, age; 69 +/- 3 SD). Ascending aorta replacement was performed in 7 cases in group E v.s. 1 in group S, aortic arch replacement in 2 v.s. 5, ascending aorta and aortic arch replacement in 1 v.s. 4 and patch replacement of the aortic wall in 1 v.s. 2, respectively. Selective cerebral perfusion (SCP) upon the cardiopulmonary bypass (CPB) was used in 45% (5/11) in group E. v.s. in 92% (11/12) in group S, p < 0.05. CPB time, aortic clamp time and SCP time were not significantly different between E group and S group. Postoperative cardiac failure, respiratory failure, renal failure, brain injury and infection occurred at insignificant rates between both groups. Thirty-day and 3-year survivorships were 73% in group E, while in group S they were 92% and 75%, respectively. In group E there were 2 cases which had aortic wall injury due to the aortic clamp used during the surgery. We recommend the use of selective cerebral perfusion and open distal anastomosis in emergency surgery for aortic arch aneurysm and/or Stanford type A aortic dissection.

A simple assay for xylanase using o-nitrophenyl-beta-D-xylobioside

We measured xylanase activities upon eight chromogenic substrates, o- or p-nitrophenyl-beta-D-xylopyranoside (oNP-X or pNP-X) and o- or p-nitrophenyl-beta-D-xylooligosaccharides (oNP-Xn or pNP-Xn, n = 2-4), and studied for their uses as substrates in a kinetic study. The Kcat and K(m) of Bacillus pumilus xylanase (EC 3.2.1.8) activities for pNP-X2 were 0.24s-1 and 0.5 mM, respectively. The relative xylanase activities with the other substrates to that with pNP-X2, pNP-X3, pNP-X4, oNP-X, oNP-X2, oNP-X3, and oNP-X4 were < 0.001, 9.4, 9.7, < 0.001, 19, 190, and 200, respectively. HPLC analysis of the digestion products of oNP-X2 or pNP-X2 showed that the xylanase hydrolyzed each of the substrates only at the ether bond between nitrophenol and xylobiose. All ether bonds of pNP-X3, oNP-X3, pNP-X4, or oNP-X4 were hydrolyzed by the xylanase and further hydrolyses proceeded in the digestion products, e.g., oNP-X2 and oNP-X3 from oNP-X4. Therefore, oNP-X2 was screened as a useful substrate in a kinetic study of the xylanase. The K(m) and Kcat of the xylanase for oNP-X2 were 0.38 mM 2.29s-1, respectively. Thermodynamic studies showed that the higher reaction rate obtained with oNP-X2 than that with pNP-X2 was due to a significant decrease in the activation energy change, despite a decrease in the activation entropy change.

[DNA synthesis in the testes of infertile men with varicocele--image cytometeric analysis of proliferating cell nuclear antigen]

BACKGROUND

The analysis of cell kinetics of germ cells have been implicated as important clue to investigate the etiology of infertile patients. We examined the germ cell kinetics of varicocele testis using proliferating cell nuclear antigen (PCNA) immunostaing by image cytometry (CAS 2000), which is very accurate and useful method to evaluate the staining intensity.

PATIENTS AND METHODS

Testicular biopsy specimen obtained from 28 cases of male infertility with left varicocele and 5 normal controls were quantitatively examined concerning PCNA expression. Positive rate of PCNA (PR) was expressed as the percent of nuclear area positively stained with PCNA monoclonal antibody compared with total nuclear area analyzed in more than 20 seminiferous tubules. A hematoxylin and eosin-stained sections, which were fixed in Bouin's solution were used to examine Johnsen's mean score by photomicroscopy.

RESULTS

PR of right and left testes of varicocele patients were 11.3 +/- 4.8% and 11.3 +/- 4.1%, respectively. PR of normal testes was 21.7 +/- 3.1%. PR of each side were reduced similarly and the difference of PR between right and left testes of varicocele patients were not significant. Bilateral PR was 11.4 +/- 4.1%. Bilateral PR was significant lower than that of normal testes (p < 0.001). Concerning varicocele grade, sperm concentration of seminogram, Johnsen's mean score and the improvement of seminogram, no significant correlations between PR and those were observed.

CONCLUSION

PR evaluated by image cytometry is very useful biological parameter to assess the germ cell kinetics. In varicocele patients, not only left side but also right side of testes were deteriorated in the cell kinetics and the decrease in DNA synthesis is one of the causes that have deleterious effects on spermatogenesis.

Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis (UC)

The third component of complement (C3) is central to both the classical and alternative pathways in complement activation. In this study, involvement of C3 activation in the mucosal injury of UC was investigated. We examined the distribution of activated (C3b) and degraded fragments (iC3b/C3dg) of C3, terminal complement complex (TCC), and complement regulatory proteins in normal and diseased colonic mucosa including UC and other types of colitis using immunohistochemical techniques at the level of light and electron microscopy. While C3b and iC3b/C3dg staining was negligible in the normal mucosa, iC3b/C3dg and, to a lesser extent, C3b were deposited in UC mucosa along the epithelial basement membrane. The deposition was enhanced in relation to the severity of mucosal inflammation (C3b, P less than 0.05; iC3b/C3dg, P less than 0.01). Epithelial deposition of TCC was not observed in most UC mucosa. Immunoelectron microscopy showed that C3b and iC3b/C3dg were distributed mainly along the epithelial basement membrane and the underlying connective tissue in a granular, studded manner, and weakly present along the basolateral surface of epithelial cells. These C3 fragments were also deposited in inflammatory control mucosa such as ischaemic and infectious colitis. Our findings suggest that deposition of the C3 fragments occurs in inflamed colonic mucosa of diverse etiologies, including UC, but to define a role of the deposition in the development of mucosal injury in UC awaits direct study.

[Comparison between high-resolution computed tomography and 99mTc-technegas SPECT pulmonary emphysema]

Scintigraphy with 99mTc-technegas was recently introduced for clinical imaging of lung ventilation. This method has been found to be useful in emergencies, to be more suitable for single photon emission computed tomography (SPECT) than other agents used in ventilation scintigraphy, and could reveal abnormalities in ventilation more easily than high resolusion computed tomography (HRCT) in pulmonary emphysema. We compared 99mTc-technegas SPECT with HRCT in six regions: the right upper, middle, and lower lobes, the left upper lobe, the lingula, and the left lower lobe, in 15 patients with pulmonary emphysema. Patients with centrilobular emphysema tended to show stronger changes in upper lobes than in lower lobes on both 99mTc-technegas SPECT and HRCT. Some regions showed no change on HRCT but various changes on 99mTc-SPECT. Patients with panlobular emphysema showed severe changes on 99mTc-SPECT in lower lung fields in which well-demarcated areas of low attenuation were not seen on HRCT. We conclude that 99mTc-SPECT is useful for detecting early changes and panlobular changes in pulmonary emphysema.

A phenomenological model describing pharyngeal pulsing in the nematode Caenorhabditis elegans anesthetized by alcohol

The recovery process of the suppressed pharyngeal pulsation in the nematode has been investigated for several concentrations of a homologous primary alcohol series (CnH2n-1OH, n = 1,2,3). A mathematical model describing the time course of the recovery process is phenomenologically constructed by using two time constants of delay time tD and recovery time tau. The values of tD and tau are obtained by fitting the equation to experimental data. The obtained values increase with increasing alcohol concentration. To observe the characteristics of tD and tau against the alcohol of order n, the inverse of these time constants are computed at 25 v/v% concentration and plotted on a semi-logarithmic scale. The plot curves decrease non-linearly and are dissimilar to the well-known curves illustrating the importance of lipid solubility in the cell membrane in anesthetic phenomena.

Loss of cerebellar Purkinje cells in aged mice homozygous for a disrupted PrP gene

Prion protein (PrP) is a glycoprotein constitutively expressed on the neuronal cell surface. A protease-resistant isoform of prion protein is implicated in the pathogenesis of a series of transmissible spongiform encephalopathies. We have developed a line of mice homozygous for a disrupted PrP gene in which the whole PrP-coding sequence is replaced by a drug-resistant gene. In keeping with previous results, we find that homozygous loss of the PrP gene has no deleterious effect on the development of these mice and renders them resistant to prion. The PrP-null mice grew normally after birth, but at about 70 weeks of age all began to show progressive symptoms of ataxia. Impaired motor coordination in these ataxic mice was evident in a rotorod test. Pathological examination revealed an extensive loss of Purkinje cells in the vast majority of cerebellar folia, suggesting that PrP plays a role in the long-term survival of Purkinje neurons.

Suppression of CD44 expression decreases migration and invasion of human glioma cells

We have reported high expression of CD44H in human glioma cells. To investigate the role of CD44H in the invasion of human glioma, we established a CD44-anti-sense-gene-expression glioma cell line named U-251A1. The expression of CD44H in the G-418-selected U-251A1 cells was reduced to 20% of that in the parental U-251SP cells, as determined by flow-cytometry analysis. We first examined the migratory responses of U-251A1 cells in vitro by time-lapse video-microscopic sparse cell-migration assay on hyaluronic acid or on chondroitin 6 sulfate. U-251A1 cells did not show significant differences in motility on any substrate, while U-251SP and other CD44H-positive cells showed dose-dependent increase of migration specifically on hyaluronic acid. To examine the physiologic function of CD44H in gliomas in vivo, U-251A1 and its control cells, U-251S1, which retain CD44-sense-expression vector, were injected stereotactically into the brains of nude mice. U-251A1 cells were localised in the region of the injection site, with relatively well demarcated borders between tumour and brain tissue, while the control cells demonstrated a cell-infiltration pattern. Our data suggest that CD44H may be required for infiltration of glioma cells through its interaction with hyaluronic acid, a major component of the brain extracellular matrix.

Expression and regulation of neuropeptide Y messenger ribonucleic acid in cultured immature rat Leydig and Sertoli cells

Neuropeptide Y (NPY) potentiates the release of gonadotropins from the pituitary in response to GnRH in the hypothalamus and modulates reproductive function. In the present study, we showed that 1) specific organs in the male rat reproductive tract express NPY messenger RNA (mRNA); 2) the multifactorial regulation of NPY mRNA in rat Leydig and Sertoli cells is temporally and hormonally regulated in vitro; 3) both Sertoli cell factor(s) and germ cell factor(s) potentiated to stimulate NPY gene levels in Leydig cells; and 4) intense NPY immunoreactivity was detected in cultured Leydig cells. Using the RT-PCR method, we found that Leydig cells, Sertoli cells, epididymis, and vas deferens expressed NPY mRNA, whereas germ cells, seminal vesicle, and prostate did not. Northern blot analyses showed that NPY mRNA was not expressed in freshly isolated immature Leydig cells, but that NPY mRNA levels were increased by the addition of LH, cytokines such as interleukin-1 alpha and -1 beta, forskolin, or phorbol 13-myristate 12-acetate. Npy mRNA levels in immature Sertoli cells were also increased by FSH. In addition, a germ cell factor(s) secreted from pachytene spermatocytes or round spermatids purified by centrifugal elutriation as well as a Sertoli cell factor(s) stimulated by FSH increased NPY gene levels in Leydig cells. Immunocytochemical analyses showed that the immunostaining was more marked in Leydig cells than in Sertoli cells in vitro. These findings indicate that testicular NPY gene expression is induced in Leydig cells or Sertoli cells by gonadotropins or cytokines within the testes, and that factors secreted from Sertoli cells or germ cells affect NPY gene expression in Leydig cells in vitro. Our findings suggest that NPY expressed in the reproductive system may modulate reproductive function as well as that in the nervous system.

Antigen-presenting-cell function of interferon gamma-treated human gingival fibroblasts

The present study was carried out to examine the antigen-presenting cell (APC) functions of human gingival fibroblasts (HGF) elicited with IFN gamma. Stimulation of HGF with IFN gamma clearly induced HLA-DR expression and enhanced expression of intercellular adhesion molecule-1 (ICAM-1) on HGF. Despite the phenotypical resemblance of IFN gamma-treated HGF to so-called APC, HLA-DR positive HGF were unable to induce proliferation of allo-reactive peripheral blood T cells (PBT) isolated from different donors. The failure of IFN gamma-treated HGF to stimulate unprimed allo-reactive PBT was not due to the lack of production of IL-1 or the immunosuppressive effect of PGE2 from HGF. On the other hand, the fact that detectable expression of CD80, ligand for CD28, was not found on IFN gamma-treated HGF may at least in part explain the ineffective function of HGF as APC. Interestingly, IFN gamma-treated HGF induced proliferation of primed allo-reactive CD4+ T cells in a HLA-DR dependent manner, suggesting that IFN gamma-treated HGF may have the ability to stimulate pre-activated T cells. We then confirmed that high levels of IFN gamma mRNA were detectable in inflamed gingival tissue. Although it cannot be concluded from this study that HGF are incapable of effectively presenting antigenic peptides to autologous T cells bearing appropriate T cell receptors, present results suggest that HGF may be affected by locally-secreted IFN gamma and that the IFN gamma-stimulated HGF may play a role in regulating immune responsiveness in inflammatory periodontal lesions.

Alteration of extracellular matrix in dilated cardiomyopathic hamster heart

The purpose of this study was to characterize the collagen in hereditary dilated cardiomyopathic hamster hearts, and to examine the participation of the collagen in the occurrence and progression of cardiomyopathy. BIO 53.58 hamsters (5, 10, 20 weeks old) were used as the model of dilated cardiomyopathy. Flb hamsters were used as controls. The collagen content was almost constant at any age in the Flb hamsters, but increased with age in BIO 53.58 hamsters. Type III collagen increased significantly in BIO 53.58 hamsters at 10 weeks. The acetic acid solubility of collagen decreased in BIO 53.58 hamsters as the fibrosis progressed, but was unchanged in controls. Reducible crosslinks showed a tendency to decrease progressively in BIO 53.58 hamsters. There were no differences between Flb and BIO 53.58 hamsters at 5 weeks, but its expression in BIO 53.58 hamsters at 10 and 20 weeks of age increased compared to Flb controls. These findings indicate that in the early phase of cardiomyopathy the extracellular matrix of the myocardium is rich in type III collagen. In the later phase, the matrix resembles that of hard tissues, whose collagen is mainly of type I collagen and is insoluble. These data suggest that the increased collagen synthesis may impair the cardiac function in the development of cardiomyopathy.

Diagnostic strategies of periodontitis based on the molecular mechanisms of periodontal tissue destruction

OBJECTIVE

Periodontitis is a disease showing differences in disease progression between patients and between sites within a patient. Routine clinical examinations today are not useful enough to distinguish susceptible patients and active lesions from resistant patients and chronic lesions. Diagnostic markers should be pathogenic and inflammatory factors participating in periodontal tissue destruction. These are both local and systemic factors.

MATERIALS AND METHODS

First of all, pathogenic factors and proinflammatory cytokines or mediators in gingival crevicular fluid (GCF) were examined and the difference was found between active and inactive periodontitis lesions distinguished by attachment loss. Active lesions were detected by discriminant-function analysis of these examinations, although the sensitivity of differential diagnosis was low. Then, we established a novel needle biopsy for understanding the pathophysiological conditions elicited in active and chronic inflammatory processes of periodontal tissue destruction. A variety of cytokines and mediators were detected in biopsied specimens by reversed transcription polymerase chain reactions (RT-PCR). Cytokine profiles were varied in inflammed periodontal biopsies. As IFN gamma mRNA expression was enhanced in inflamed gingiva, antigen-presenting-cell (APC) functions of human gingival fibroblasts (HGF) were examined.

RESULTS

Despite the phenotypical resemblance of IFN gamma-treated HGF to so-called APC, HLA-DR positive HGF could not induce proliferation but suppressed proliferation of alloreactive peripheral blood T cells (PBT). However, HLA-DR positive HGF stimulated the proliferative responses of PBT which had been primed with allo-APC. Regulatory immune responses by IFN gamma were different in T cell conditions.

CONCLUSIONS

Various kinds of cytokines participated in periodontal inflammation, and every cytokine is multi-functional. Complex and compound inflammatory processes can be clarified by examining cytokine networks and the precise effects of each cytokine on each of the cell types comprising periodontal tissue. It is, therefore, necessary for establishing diagnostic strategies to integrate pathogenic and inflammatory factors in periodontal tissue destruction.

A novel dipeptidyl aminopeptidase from Pseudomonas sp. strain WO24

An activity similar to that of dipeptidyl aminopeptidase I (DAP I) which releases dipeptide from Gly-Arg-p-nitroanilide (Gly-Arg-pNA) was detected in a Pseudomonas sp. An enzyme was isolated and purified about 400-fold by a series of column chromatographies. The enzyme, named DAP BI (DAP from bacteria, type I), was revealed to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing. The molecular mass was estimated to be 82 kDa by SDS-PAGE and 65 kDa by gel filtration, suggesting that the enzyme may be a monomer. The enzyme had an isoelectric point of 4.7. It is optimally active at pH 9.0. The Km and Vmax of the enzyme for Gly-Arg-pNA were 0.25 mM and 195 micromol/min/mg, respectively. The purified enzyme did not hydrolyze Gly-Phe-pNA, which was also a substrate for DAP I, whereas it hydrolyzed Arg-Arg-4-methoxy-beta-naphthylamide (Arg-Arg-MNA), a model substrate for DAP III. The Km and Vmax for Arg-Arg-MNA were 0.019 mM and 145 micromol/min/mg, respectively. This purified enzyme can also catalyze the removal of Asp-Arg from the N termini of angiotensins I and II. The enzyme activity was completely inhibited by Zn(II) (0.5 mM), tosyl-L-Lys-chloromethyl ketone (0.1 mM), and leupeptin (0.1 mM) and partially inhibited by Co(II) (0.5 mM) and chymostatin (0.1 mM), whereas the enzyme was not affected by general serine protease inhibitors (phenylmethylsulfonyl fluoride and diisopropylfluorophosphate) and thiol protease inhibitors. The substrate specificity, classification of catalytic site, and other enzymatic properties demonstrate that this enzyme is distinct from the previously described mammalian DAPs I and III and Saccharomyces cerevisiae DAP III. These results indicate that DAP BI may be a new type of the DAP family.

Molecular cloning of murine decay accelerating factor by immunoscreening

Although the cDNA of human decay accelerating factor (DAF) which restricts complement activation on homologous cell membranes was cloned in 1987, all trials to detect the cDNA of mouse DAF by cross-hybridization were unsuccessful. However, by immunoscreening with a rabbit antiserum against purified mouse DAF, we successfully cloned the cDNA. It contains four typical short consensus repeats (SCR) similar to that in human and guinea pig DAF. The base sequence showed 63.7 and 63.8% identity to that of human and guinea pig DAF respectively. The deduced amino acid sequence identity to human and guinea pig DAF was 47.2 and 46.5% respectively. Mouse complement receptor related gene Y (Crry)/p65 function is comparable to DAF. SCR3 and SCR4 of mouse DAF showed 50% identity to SCR2 and SCR3 of Crry/p65 respectively. Identification of the mouse DAF gene should open a new approach for determining the actual in vivo role of DAF by analyzing autoimmune mice as well as generating DAF gene knockout mice using embryonic stem cells.

Delayed and diminished pressor response to muscle sympathetic nerve activity in the elderly

We studied the effects of aging on alpha-receptor-mediated vasoconstrictive responses to sympathetic nerve activity in 16 healthy aged [75.8 +/- 2.7 (SE) yr] and young men (33.8 +/- 2.0 yr). Muscle sympathetic nerve activity (MSNA), heart rate, and blood pressure were analyzed during slow respiration (0.1 Hz). Peak amplitude and phase were calculated from a cosine function fitted with 0.1 Hz by using the least squares method. The latency of the pressor response to MSNA, defined as lag time from the peak of MSNA to diastolic blood pressure, was significantly longer in the aged than the young group (7.1 +/- 0.3 vs. 5.4 +/- 0.4 s; P < 0.01). The extent of pressor response to MSNA, defined as diastolic blood pressure rise in response to increase in total MSNA, was significantly lower in the aged than the young group (0.038 +/- 0.006 vs. 0.099 +/- 0.024 mmHg/unit, P < 0.001). These results suggest that alpha-receptor-mediated vasoconstrictive responses to MSNA may be attenuated in the elderly.

Interleukin-4 modulates collagen synthesis by human mesangial cells in a type-specific manner

Several studies have suggested an involvement of interleukin (IL)-4 in the pathophysiology of glomerulonephritis (GN). To elucidate its possible role in GN, we have investigated the effect of IL-4 on collagen accumulation by human mesangial cells (MC). After incubation with IL-1 alpha and/or IL-4 for 48 h, type I, III, and IV collagens in both soluble and cell-associated forms were identified by Western blotting. IL-1 alpha stimulated type I and IV collagen synthesis, lacking significant effect on type III collagen synthesis. In contrast, IL-4 stimulated type III collagen synthesis without affecting type I and type IV synthesis. Enzyme-linked immunosorbent assay confirmed the dose-dependent effect of IL-4 on collagen type III secretion (2.0-fold at 10 ng/ml). Importantly, IL-1 alpha-stimulated type I and IV collagen synthesis was suppressed by concomitant IL-4 treatment. Northern analysis of type I and III procollagen mRNAs displayed consistent results. These data indicate that IL-4 selectively stimulates type III collagen synthesis but also suppresses IL-1 alpha-stimulated type I and IV collagen synthesis. Therefore IL-4 could potentially contribute to the pathological changes in glomerular diseases in cooperate with other cytokines.

Inhibitory effect of double transfection to xenoendothelial cells using both decay accelerating factor and homologous restriction factor 20 genes on complement dependent cytolysis

Hyperacute rejection in discordant xenotransplantation occurs due to the complement activation via classical and/or alternative pathway. Regulator of complement activation (RCA) molecules inhibit species-specific complement dependent cytolysis. To confirm the effect of gene engineering using double RCA molecules on xenogeneic cells, the inhibitory effect on complement dependent cytolysis was compared between bovine aortic endothelial cells (BAEC) doubly transfected with both decay accelerating factor (DAF) and homologous restriction factor (HRF) 20 cDNA and BAEC singly transfected with DAF alone using retroviral vector. The positive percent expression of DAF and HRF20 antigen on double transfectant (BAEC/D+H) was 97.0% and 95.0%, respectively, whereas that of DAF antigen on single transfectant (BAEC/D) was 97.0%. After incubated with 25% human serum and anti-BAEC antibody, the viability of double transfectant (BAEC/ D+H) was significantly preserved, compared with that of single transfectant (BAEC/D). These findings demonstrated that xenoendothelial cells doubly transfected with both DAF and HRF20 cDNA could be protected from complement dependent cytolysis more effectively than those singly transfected with DAF alone in the presence of antixenoendothelial antibody.

Insulin receptor mRNA in the substantia nigra in Parkinson's disease

Neurotrophic effects resulting from the insulin/insulin receptor system have been recognized as important in determining the etiological basis of neurodegenerative disorders. In Parkinson's disease, selective neuronal loss in the substantia nigra is accompanied by decreased immunoreactivity of the insulin receptor as determined using immunohistochemical studies. We performed semiquantitative mRNA analysis by reverse transcription-polymerase chain reaction (RT-PCR) using specific primers for human insulin receptor exon 22, which encodes a region of the beta subunit of the receptor serving as a tyrosine kinase domain. The relative levels of mRNA in the substantia nigra from Parkinson's brain tissues showed a marked depression compared with those of normal controls. Further investigations are needed to decide whether this is a primary, disease-specific alteration of gene expression or merely a secondary process.

Local inflammation caused by a monoclonal antibody that blocks the function of the rat membrane inhibitor of C3 convertase

The participation of membrane inhibitors in C-mediated inflammation in vivo was analyzed in rats with the use of mAbs against membrane inhibitors of C. 512Ag inhibits C3 convertase of homologous rat C and rat CD59 prevents the formation of homologous membrane attack complexes. The histologic distributions of 512Ag and CD59 in rat skin were essentially the same. However, although intracutaneous administration of mAb against 512Ag (anti-512Ag) in the form of F(ab')2 induced a remarkable inflammatory response visualized by exudation of Evans blue that had been previously injected i.v., the mAb against CD59 caused no inflammatory exudate. Furthermore, anti-512Ag F(ab')2 caused deposition of C3 followed by intense polymorphonuclear leukocyte infiltration and hemorrhage at the injection sites within 24 h. This reaction was completely abrogated by depletion of C. Therefore, spontaneous C activation on self cell membranes requires amplification at the C3 convertase step, which is restricted by membrane inhibitors such as 512Ag, thus preventing inflammation. A type II allergic response might preferentially occur at sites that exhibit an impairment of membrane inhibitor(s) of C3 convertase. However, although depletion of leukocytes by preadministration of cyclophosphamide did not reduce C3 deposition by anti-512Ag. Evans blue exudation was appreciably reduced, indicating that infiltrated leukocytes play a role in enhancing and prolonging inflammation initiated by local C activation.

Local inflammation caused by a monoclonal antibody that blocks the function of the rat membrane inhibitor of C3 convertase

The participation of membrane inhibitors in C-mediated inflammation in vivo was analyzed in rats with the use of mAbs against membrane inhibitors of C. 512Ag inhibits C3 convertase of homologous rat C and rat CD59 prevents the formation of homologous membrane attack complexes. The histologic distributions of 512Ag and CD59 in rat skin were essentially the same. However, although intracutaneous administration of mAb against 512Ag (anti-512Ag) in the form of F(ab')2 induced a remarkable inflammatory response visualized by exudation of Evans blue that had been previously injected i.v., the mAb against CD59 caused no inflammatory exudate. Furthermore, anti-512Ag F(ab')2 caused deposition of C3 followed by intense polymorphonuclear leukocyte infiltration and hemorrhage at the injection sites within 24 h. This reaction was completely abrogated by depletion of C. Therefore, spontaneous C activation on self cell membranes requires amplification at the C3 convertase step, which is restricted by membrane inhibitors such as 512Ag, thus preventing inflammation. A type II allergic response might preferentially occur at sites that exhibit an impairment of membrane inhibitor(s) of C3 convertase. However, although depletion of leukocytes by preadministration of cyclophosphamide did not reduce C3 deposition by anti-512Ag. Evans blue exudation was appreciably reduced, indicating that infiltrated leukocytes play a role in enhancing and prolonging inflammation initiated by local C activation.