Long-term results of cyclosporine-induced remission of relapsing nephrotic syndrome in children

Twenty-nine children with nephrotic syndrome were treated with cyclosporine (CsA), 100 mg/m2/day for 6 months and prednisone, 2 mg/kg every other day for 1 month and then subsequently 1 mg/kg every other day for 5 months. A renal biopsy had shown minimal change disease (MCD) in 18 children, focal segmental glomerulosclerosis (FSGS) in 3 children, membranous glomerulonephritis (MGN) in 4 children, membranoproliferative glomerulonephritis (MPGN) in 2 children, and IgA nephropathy in 2 children. All MCD patients went into complete remission during therapy. Five out of 11 steroid-sensitive patients (45.5%) remained in complete remission, while the remaining 6 (54.5%) had 2 to 3 relapses, 19 to 47 months after CsA discontinuation. Two out of 7 steroid-resistant patients (28.6%) were still in complete remission and 5 (71.4%) had 1 to 6 relapses 25 to 49 months after CsA withdrawal. The mean number of relapses in the steroid-sensitive group before and after CsA treatment decreased more (8.5 vs 1.4) than in the steroid-resistant group (8.1 vs 2.4) (p < 0.05). At the most recent examination, 1 of 3 FSGS patients achieved complete remission and 2 had a partial response. Three of 4 MGN patients were in complete remission and 1 was in partial remission. One of 2 MPGN patients achieved complete remission and 1 showed partial remission. Two patients with IgA nephropathy were in partial remission. We compared MCD patients in sustained remission and relapse; the mean CD4/CD8 ratio decreased from 1.5 to 0.9 in the remission group, in comparison with no change in the relapsed group (p < 0.05). The posttreatment renal biopsy showed lesions of nephrotoxicity in 3 of 18 children with MCD whose renal function did not alter after CsA treatment. We concluded: 1) A 6-month treatment of CsA, in combination with a low-dose alternate-day steroid, proved to be effective in maintaining the remission of steroid-sensitive and steroid-resistant MCD patients. 2) The CD4/CD8 ratio can be used as a index to predict remission or relapse after CsA therapy.

Dietary alpha-linolenic acid increases the biosynthesis of the choline glycerophospholipids from [14C]CDPcholine in rat liver and kidney but not in brain

The effect of feeding rats for 30 days with diets containing high levels of linoleic acid (sunflower oil, SO) or alpha-linolenic acid (perilla oil, PO) was studied in the liver, kidney and brain. The PO group showed a higher labeling of choline glycerophospholipids (CGP) in liver and kidney but no difference with the SO group in ethanolamine glycerophospholipids (EGP) labeling. The brain displayed the lowest incorporation of both precursors and no difference between the two diets. Analyses of brain CGP and EGP fatty acid composition showed that in the PO group the ratio n-6/n-3 was lower than in the SO group, mainly as a consequence of lower levels of n-6 fatty acids. The mole % of docosahexaenoate (DHA) in these lipids was the same for both groups and only triacylglycerols (TAG) displayed a higher DHA. Therefore, at least in the brain, the magnitude of fatty acid changes observed in CGP and EGP for the PO group does not affect the uptake/incorporation of the precursors into phospholipids.

Aromatic-aromatic ring interaction revisited with model compounds of Wilcox

Aromatic-aromatic nonbonded interactions have been reexamined using model compounds of Wilcox and collaborators (J. Am. Chem. Soc. 1994, 116, 4497). It was found that at low temperatures down to 210 degrees K, the population of the folded conformers (A) is higher than that of the unfolded conformers (B), suggesting that edge-to-face aromatic-aromatic ring interactions are in effect. However, the free energy difference between the two types of conformers did not vary linearly with temperature, which is against what we expected from the thermodynamic relationship of delta G = delta H-T delta S. This suggests that in the presence of solvent molecules a free energy cancellation effect operates between the two conformers. Although A has a free energy gain of only approximately 0.5 kcal/mol over B in organic solvents, as obtained by subtracting the solvent-induced unfolding effect, it could still be a significant energy with respect to conformational preference.

Simulation and fabrication of attenuated phase-shifting masks: CrF(x)

To acquire the required resolution for 248- and 193-nm lithography, a study of attenuated phase-shifting mask (Att-PSM) technology is in progress. We performed a simulation study using a matrix method to calculate relative transmittance and the amount of phase shift of light through the PSM. However, we found that the average film composition changed with deposition time. Accordingly, optical constants were found to be a strong function of film thickness. Therefore we rearranged the relationship between deposition parameters (e.g., deposition time or gas flow rate ratio) and optical constants (e.g., refractive index and extinction coefficient) to extract the empirical formula for the optical constants with respect to film composition. To verify our simulation study, we fabricated a phase shifter based on our simulation result, which was found to have a transmittance of 8.3% and a phase shift of 179.5 degrees . Consequently, we obtained a reliable optimum condition for the deep-ultraviolet Att-PSM.

Co-duplication of a variant surface glycoprotein gene and its promoter to an expression site in African trypanosomes

Activation of the metacyclic variant antigen type 7 (MVAT7) variant surface glycoprotein (VSG) gene in bloodstream Trypanosoma brucei rhodesiense involves a duplicative transposition of the gene. The DNA transposition unit extends from a site approximately 3.0 kilobases upstream of the VSG gene through the coding region and includes a 73-base pair sequence that possesses promoter activity in transient transfections. This MVAT7 promoter has 80% identity to a previously characterized promoter for the MVAT4 VSG gene. Nuclear run-on assays demonstrate that the MVAT7 promoter is active in MVAT7 bloodstream organisms and that its transcript is synthesized by an RNA polymerase resistant to alpha-amanitin, consistent with previously published reports regarding VSG gene transcription. The transcription start site was identified by primer extension studies and a modified rapid amplification of cDNA ends protocol. Selective mutational analysis of the MVAT7 promoter showed that two conserved trinucleotide regions are important for full promoter function. This study demonstrates that the MVAT7 VSG gene is co-duplicated with its promoter and transcribed into a monocistronic precursor RNA.

Homocysteine in sickle cell disease: relationship to stroke

PURPOSE

The risk factors and pathophysiology of stroke and other serious complications of sickle cell disease (SCD) are poorly defined. Hyperhomocysteinemia has recently been identified as a risk factor for stroke and other vascular diseases in the general population, however its role in SCD has not been investigated.

PATIENTS AND METHODS

We measured serum homocysteine and red cell folate levels in 100 patients with SCD, including 16 patients with stroke. A disease severity score was determined for all patients and those without stroke were classified into mild (44 patients) or severe (40 patients) disease groups.

RESULTS

Homocysteine levels for the stroke group (median 13.3 mumol/L, mean 13.1 +/- 4.3 mumol/L) were significantly higher than those in patients without stroke (median 9.7 mumol/L, mean 10.7 mumol/L) (P < 0.02), and on multiple regression analysis homocysteine level was independently correlated with stroke (P < 0.026). Homocysteine and folate levels were inversely correlated (r = -0.41, P < 0.00005). Using logistic regression, the odds ratio for stroke in patients with homocysteine levels above the median (10.1 mumol/L) was 3.5 in this group of patients (95% confidence interval 1.1 to 11.9).

CONCLUSION

High homocysteine levels may be a risk factor for development of stroke in SCD patients. The role of homocysteine in the pathogenesis of stroke in SCD needs to be examined in a longitudinal, prospective study.

Seed transmission of cucumber mosaic virus in spinach

ABSTRACT Spinach (Spinacia oleracea) seed from a commercial breeding line suspected of harboring cucumber mosaic virus (CMV) was analyzed for seed transmission of the virus. Initial seed grow-out tests and enzymelinked immunosorbent assay studies indicated that CMV was present in this seed lot at a level of nearly 15%. To verify these results and gain insight into the mechanism of seed transmission, four combinations of crosses between healthy and/or infected parent plants were conducted. None of the spinach seedlings derived from crossing healthy male and healthy female plants contained CMV, whereas a portion of seedlings derived from all of the other three crosses, i.e., healthy male and infected female, infected male and healthy female, and infected male and infected female plants, were infected with CMV. The results demonstrate that CMV is seed transmitted in spinach and indicate that both male and female parent plants can serve as infection sources. Ultrastructural studies, including immunogold labeling, revealed the presence of virus particles in the cytoplasm of ovary wall cells, ovule integuments and nucellus, anther, and seed-coat cells, as well as fine fibril-containing vesicles and electron-dense inclusions of amorphous aggregates in the central vacuoles of these cells. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify 860-bp cDNA fragments containing the CMV coat protein (CP) gene from the embryo, endosperm, and pollen tissues of CMV-infected plants. Taken together, these studies indicate that CMV occurs in virtually all spinach reproductive tissues. Analysis of several RT-PCR amplified and cloned CP genes and flanking sequences from parent and progeny plants revealed that the spinachinfecting CMV was a member of subgroup II. Furthermore, cDNA sequencing and restriction endonuclease mapping consistently revealed two sequence variants, designated SP103 and SP104, in most plants analyzed. These data suggest that there may have been mixed infections of two distinct, seed-transmitted CMV variants in spinach.

The effect of dietary threonine on Adh expression during the development of Drosophila melanogaster

The alcohol dehydrogenase (ADH) activity and ADH cross reacting material (ADH CRM) were measured and Northern blot analysis was carried to define the function and the regulation mechanism of the Adh gene. This study examined how dietary threonine affects the expression of the Adh gene during development of Drosophila melanogaster. Two wild type strains, one homozygous for Adh(F) and one for Adh(S) from Chunan, Korea were used. The ADH activity and CRMs of the Adh(F) strain were 2.1 times higher than those of Adhs strain, and ADH activity was higher with isopropanol (secondary alcohol) than with ethanol (primary alcohol) as a substrate in both Adh(F) and Adh(S) strains. When the larvae, pupae, newly emerged adults (0-1 day), and adults (5-7 days) of Drosophila melanogaster Adh(F) and Adh(S) strains were fed on a defined low yeast and threonine medium, ADH activity and ADH CRM levels were increased. Northern blot analyses indicated that the production of mRNA of the larvae, young adults (0-1 day), and adults (5-7 days) was increased by dietary threonine. ADH activity and ADH CRM increases in Drosophila melanogaster fed on threonine were as a result of threonine-stimulated alteration in the amount of ADH mRNA. The elevated level of the ADH mRNA transcribed from the proximal and distal promoters of threonine-fed larvae and adults showed that there was an induction.

A T-DNA gene required for agropine biosynthesis by transformed plants is functionally and evolutionarily related to a Ti plasmid gene required for catabolism of agropine by Agrobacterium strains

The mechanisms that ensure that Ti plasmid T-DNA genes encoding proteins involved in the biosynthesis of opines in crown gall tumors are always matched by Ti plasmid genes conferring the ability to catabolize that set of opines on the inducing Agrobacterium strains are unknown. The pathway for the biosynthesis of the opine agropine is thought to require an enzyme, mannopine cyclase, coded for by the ags gene located in the T(R) region of octopine-type Ti plasmids. Extracts prepared from agropine-type tumors contained an activity that cyclized mannopine to agropine. Tumor cells containing a T region in which ags was mutated lacked this activity and did not contain agropine. Expression of ags from the lac promoter conferred mannopine-lactonizing activity on Escherichia coli. Agrobacterium tumefaciens strains harboring an octopine-type Ti plasmid exhibit a similar activity which is not coded for by ags. Analysis of the DNA sequence of the gene encoding this activity, called agcA, showed it to be about 60% identical to T-DNA ags genes. Relatedness decreased abruptly in the 5' and 3' untranslated regions of the genes. ags is preceded by a promoter that functions only in the plant. Expression analysis showed that agcA also is preceded by its own promoter, which is active in the bacterium. Translation of agcA yielded a protein of about 45 kDa, consistent with the size predicted from the DNA sequence. Antibodies raised against the agcA product cross-reacted with the anabolic enzyme. These results indicate that the agropine system arose by a duplication of a progenitor gene, one copy of which became associated with the T-DNA and the other copy of which remained associated with the bacterium.

TNF-alpha opens a paracellular route for HIV-1 invasion across the blood-brain barrier

BACKGROUND

HIV-1 invades the central nervous system early after infection when macrophage infiltration of the brain is low but myelin pallor is suggestive of blood-brain-barrier damage. High-level plasma viremia is a likely source of brain infection. To understand the invasion route, we investigated virus penetration across in vitro models with contrasting paracellular permeability subjected to TNF-alpha.

MATERIALS AND METHODS

Blood-brain-barrier models constructed with human brain microvascular endothelial cells, fetal astrocytes, and collagen I or fibronectin matrix responded in a dose-related fashion to cytokines and ligands modulating paracellular permeability and cell migration. Virus penetration was measured by infectious and quantitative HIV-1 RNA assays. Barrier permeability was determined using inulin or dextran.

RESULTS

Cell-free HIV-1 was retained by the blood-brain barrier with close to 100% efficiency. TNF-alpha increased virus penetration by a paracellular route in a dose-dependent manner proportionately to basal permeability. Brain endothelial cells were the main barrier to HIV-1. HIV-1 with monocytes attracted monocyte migration into the brain chamber.

CONCLUSIONS

Early after the infection, the blood-brain barrier protects the brain from HIV-1. Immune mediators, such as TNF-alpha, open a paracellular route for the virus into the brain. The virus and viral proteins stimulate brain microglia and macrophages to attract monocytes into the brain. Infiltrating macrophages cause progression of HIV-1 encephalitis.

Cancer incidence rate and mortality rate in sickle cell disease patients at Howard University Hospital: 1986-1995

The incidence of cancer in patients with sickle cell disease (SCD) is not known. The 10-year follow-up data on 696 patients with SCD was analyzed at our institution in order to determine the cancer incidence and cancer mortality rates. The age range was 18 to 79 years, with a mean age of 28.8 years. There were 377 females and 319 males. The median follow-up was 3 years. Five patients developed cancer during this period. The cancer incidence rate was 5/2,864 or 1.74 per 1,000 patient years. The 95% CI was 0.64 to 4.32 per 1,000 patient years. There were 68 deaths with 3 being due to cancer. The cancer mortality rate was 3/2,873 or 1.04 cases per 1,000 patient years. Our data represent the first published paper that the authors are aware of, where the cancer incidence and mortality rates have been calculated for any group of patients with SCD.

Structure/function relationship of the cAMP response element in tyrosine hydroxylase gene transcription

Expression of tyrosine hydroxylase (TH) is limited to catecholamine-producing neurons and neuroendocrine cells in a cell type-specific manner and is inducible by the cAMP-regulated signaling pathway. Previous results indicated that the cAMP response element (CRE) residing at -45 to -38 base pairs upstream of the transcription initiation site is essential for both basal and cAMP-inducible promoter activity of the 2.4-kilobase or shorter upstream sequence of the TH gene (Kim, K. S., Lee, M. K., Carroll, J. , and Joh, T. H. (1993) J. Biol. Chem. 268, 15689-15695; Lazaroff, M. , Patankar, S., Yoon, S. O., and Chikaraishi, D. M. (1995) J. Biol. Chem. 270, 21579-21589). Here, we further report that the CRE is critical for the promoter activity of the 5.6- or 9.0-kilobase upstream sequences of the rat TH gene, which had been shown to direct the cell-specific TH expression in vivo. To define the structure/function relationship of the CRE in transcriptional activation of the TH gene, we performed saturated mutational analyses of 12 nucleotides encompassing the CRE. Mutation of any nucleotide within the octamer motif results in a significant decrease of both basal and cAMP-inducible transcriptional activity of the TH reporter gene construct. Among the four nucleotides adjacent to the CRE (two 5' and two 3'), only the G residue at the immediate 3' position is important for full transcriptional activity. DNase I footprint analysis indicates a positive correlation between in vivo promoter activity and in vitro interaction between the CRE motif and its cognate protein factor(s). Reconstruction experiments using a TH promoter in which the native CRE was rendered inactive show that the CRE can transactivate transcription in either orientation through a window of approximately 200 base pairs upstream of the transcription initiation site, suggesting that CRE supports transcriptional activation of the TH gene in a distance-dependent manner. Finally, when the distance between the CRE and TATA box was changed by inserting an additional 5 or 10 bases, it was observed that both insertional mutations increased activity by approximately 3-fold. The cAMP inducibility was as intact as the wild type construct. Together, these results are consistent with a model in which transcriptional activation of the TH gene by the CRE requires that it be located within a certain proximity of the CAP site but does not depend on a stringent stereospecific alignment in relationship to the TATA element.

Synthetic MHC class I peptide prolongs cardiac survival and attenuates transplant arteriosclerosis in the Lewis-->Fischer 344 model of chronic allograft rejection

BACKGROUND

A synthetic peptide corresponding to residues 75-84 of the alpha1 domain of HLA-B7 molecule (HLA-B7.75-84 [Allotrap]) inhibits cytotoxic T cell function in vitro and, when combined with subtherapeutic doses of cyclosporine (CsA), prolongs allogeneic cardiac survival. We now report the effects of HLA-B7.75-84 in the Lewis --> Fischer 344 rat model of chronic cardiac allograft rejection.

METHODS

Animals were treated with CsA (5 mg/kg/day s.c.) alone or with CsA plus alternate-day HLA-B7.75-84 (20 mg/kg/day i.p.) for 30 days. Allografts harvested at day 100 were evaluated by histology and immunohistology.

RESULTS

HLA-B7.75-84 plus CsA prolonged allograft survival (75% of allografts survived >90 days) compared with CsA alone (27% of allografts survived >90 days) (P<0.05). Histologic examination of control allografts showed dense cellular infiltrates and moderate transplant arteriosclerosis (>75% of arteries showed 10-20% occlusion). Infiltrating leukocytes consisted of macrophages (>75% cells), T cells (10-20%), and rare natural killer cells (<5%). Cell activation was shown by expression of major histocompatibility complex class II antigens (>75%), interleukin (IL) 2 receptor (5-10%), and staining for IL-2 (approximately 5% of intragraft mononuclear cells), interferon-gamma (5-10%) and tumor necrosis factor-alpha (approximately 20%). Leukocytes and vessels also showed labeling for the fibrogenic cytokine, transforming growth factor-beta, and all vessels showed dense deposition of IgG (IgG2a, IgG2b) and C3. The addition of HLA-B7.75-84 decreased overall cellularity (P<0.01) without affecting the composition of the infiltrate, but completely prevented transplant arteriosclerosis, diminished myocardial injury, and abrogated expression of IL-2R, IL-2, interferon-gamma, tumor necrosis factor-alpha, and transforming growth factor-beta. HLA-B7.75-84 also blunted the humoral response, which resulted in a predominance of vascular deposition of the non-complement-fixing IgG2c isotype and a concomitant decrease in C3.

CONCLUSIONS

Therapy with synthetic class I major histocompatibility complex peptide (HLA-B7.75-84) attenuates key histologic features of graft arteriosclerosis, in association with inhibition of multiple cytokines and growth factors and modulation of host alloantibody responses in vivo, which is of interest since Allotrap is currently undergoing clinical trials.

Identification and characterization of S fimbria-binding sialoglycoproteins on brain microvascular endothelial cells

We have previously shown that S-fimbriated Escherichia coli binds brain microvascular endothelial cells (BMEC) via a lectin-like activity of SfaS adhesin specific for NeuAc alpha2,3-galactose; however, BMEC molecules bearing these epitopes have not been identified. In the present study, we showed that the expression of S fimbriae conferred a three-fold increase in adhesion of E. coli to cow, human, and rat BMEC but did not enhance E. coli adhesion to systemic vascular endothelial cells such as human umbilical vein endothelial cells and human aortic arterial endothelial cells. Two BMEC-binding molecules for S fimbriae were identified as 65 (major)- and 130 (minor)-kDa sialoglycoproteins by S fimbria immunoblotting and were purified from bovine BMEC by wheat germ agglutinin and Maackia amurensis lectin (specific to NeuAc alpha2,3-galactose) affinity chromatography. The 65-kDa BMEC glycoprotein showed effective inhibition of S fimbria-mediated binding of E. coli to BMEC. Polyclonal antibodies raised against the mixture of 65- and 130-kDa proteins reacted to 65-kDa protein present only on BMEC, not on systemic vascular endothelial cells. Immunoprecipitation of biotinylated BMEC membrane proteins and immunocytochemistry studies of BMEC with anti-S fimbria-binding protein antibodies revealed that the 65-kDa protein is a surface protein. The N-terminal amino acid sequence of 65- and 130-kDa proteins showed no significant sequence homology with any other known proteins. These findings suggest that 65- and 130-kDa proteins represent novel sialoglycoproteins involved in the binding of S-fimbriated E. coli to BMEC.

Molecular cloning and expression of human alpha2,8-sialyltransferase (hST8Sia V)

The cDNA encoding human alpha2,8-sialyltransferase (hST8Sia V) which exhibits activity toward gangliosides, GM1b, GD1a, GT1b, and GD3, was isolated by screening of human brain cDNA library with a DNA probe generated from the cDNA sequence of mouse ST8Sia V (mST8Sia V) and by 5'-RACE of mRNA from human brain tissue. Comparative analysis of this cDNA with mST8Sia V showed that each sequence of the predicted coding region contains 84% identity in both nucleotide and amino acid. Northern analysis of this cDNA indicated that, in contrast to mST8Sia V, two different sizes of transcripts corresponding to 11 and 2.5 kb were expressed in both human fetal and adult brain, while the transcript of 2.5 kb was detected only in adult heart and skeletal muscle. The enzyme expressed in COS cells showed a substrate specificity very similar to that of mST8Sia V.

Protein kinase A coordinately regulates both basal expression and cyclic AMP-mediated induction of three catecholamine-synthesizing enzyme genes

Studies have shown that the cyclic AMP-regulated pathway is involved in the activation of tyrosine hydroxylase (TH) and in the induction of gene expression of the three catecholamine-synthesizing enzymes, TH, dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT). In the present study we investigated further the role of protein kinase A (PKA) in the regulation of both basal and cyclic AMP-inducible transcription of the three catecholamine-synthesizing enzymes in primary cultured bovine chromaffin cells by using the PKA-specific inhibitor N-[2-(p-bromocinnamylamine)ethyl]-5-isoquinolinesulfonamide (H-89). In the presence of 40 microM H-89, mRNA levels of TH, DBH, and PNMT were reduced to 17 +/- 8, 19 +/- 8, and 14 +/- 2% of the untreated control, respectively, in 24 h, and intracellular norepinephrine and epinephrine levels were decreased to 20 and 34%, respectively, in 72 h. At 20 microM, although the basal enzyme gene expression levels were little affected, their induction by forskolin was abolished and norepinephrine and epinephrine levels fell to 55 and 74%. This reduction in catecholamines at 20 microM was probably due to changes in the phosphorylation state of TH, as its enzymatic activity was found to be decreased to 66 and 69% in 48 and 72 h, respectively. Thus, PKA activity in bovine adrenal medullary cells coordinately regulates both basal and cyclic AMP-inducible gene expression of specific catecholamine-synthesizing enzymes, resulting in changes in intracellular catecholamine levels available for consequent neurohormonal activities.

Selective expression of adhesion molecules on human brain microvascular endothelial cells

Human microvascular endothelial cells were isolated from children's brain and examined for their morphological characteristics and upregulation of cell adhesion molecules in response to TNF alpha. Our human brain microvascular endothelial cells (HBMEC) were positive for factor VIII-Rag, carbonic anhydrase IV, Ulex Europeus Agglutinin I, took up fluorescently labeled acetylated low density lipoprotein and expressed gamma glutamyl transpeptidase, demonstrating their brain endothelial cell characteristics. Upon treatment with TNF alpha. VCAM and ICAM but little ELAM was expressed on HBMEC, while VCAM, ICAM and ELAM were clearly evident on HUVEC. This selective expression of cell adhesion molecules was also demonstrated by in situ stimulation of brain tissues. In conclusion, microvascular endothelial cells from childrens brains display selective expression of cell adhesion molecules, which differ from macrovascular endothelial cells. This may have consequences for leukocyte trafficking into the central nervous system.

Immunoreactivity of presenilin-1 in human, rat and mouse brain

Monoclonal antibodies (mAbs) D3G6 and C8A5, specific for amino acid residues 160-168 of S182 protein, immunolabeled neurons, ependymal and choroid plexus cells, and myocytes in brain sections from normal subjects and people with Alzheimer disease or Down syndrome and in rats and mice. Oligodendroglia, microglia, and the majority of astrocytes were negative. S182 protein or a fragment of the protein detected with these mAbs is not a constituent of amyloid-beta deposits or tangles.

AM67, a secretory component of the guinea pig sperm acrosomal matrix, is related to mouse sperm protein sp56 and the complement component 4-binding proteins

The guinea pig sperm acrosomal matrix is the dense core of the acrosome and is likely to be important in acrosome biogenesis and fertilization. Isolated acrosomal matrices are composed of a limited number of major bands when analyzed by SDS-polyacrylamide gel electrophoresis, among which is a Mr 67,000 protein that we have termed AM67. Indirect immunofluorescence demonstrated that AM67 is localized to the apical segment of the cauda epididymal sperm acrosome. Immunoelectron microscopy further refined the localization of AM67 to the M1 (dorsal bulge) domain within the acrosome. Using a polymerase chain reaction product based upon tryptic peptide sequences from AM67, a lambdagt11 guinea pig testis cDNA library was screened to yield two cDNA clones that encode the AM67 peptides. Northern analysis revealed that AM67 is transcribed as a 1. 9-kilobase testis-specific mRNA. The complete AM67 sequence encodes a prepropolypeptide of 533 amino acids with a calculated Mr of 59, 768. Following cleavage of a probable signal sequence, the polypeptide was predicted to have a Mr of 56,851 and seven consensus sites for asparagine-linked glycosylation. The deduced amino acid sequence of AM67 is most similar to those of the mouse sperm protein sp56 and the alpha-subunits of complement component 4-binding proteins from various mammalian species. Although mouse sp56 has been reported to be a cell-surface receptor for the murine zona pellucida glycoprotein ZP3, standard immunoelectron microscopy using the anti-sp56 monoclonal antibody 7C5 detected sp56 within the mouse sperm acrosome, but failed to detect sp56 on the surface of acrosome-intact mouse sperm. Furthermore, acrosomal labeling was detected in mouse sperm prepared for immunofluorescence using paraformaldehyde fixation, but was not observed with live unfixed sperm. Thus, the finding that sp56 is present within the acrosome provides further support that sp56 and AM67 are orthologues and suggests that sp56 may function in acrosomal matrix-zona pellucida interactions during and immediately following the acrosome reaction in the mouse.

Novel homozygous and compound heterozygous mutations of sterol 27-hydroxylase gene (CYP27) cause cerebrotendinous xanthomatosis in three Japanese patients from two unrelated families

The autosomal recessively inherited cholesterol metabolic disease, cerebrotendinous xanthomatosis (CTX), is caused by mutations in the sterol 27-hydroxylase gene. Three Japanese CTX patients from two unrelated families were studied genetically. By DNA sequence analysis a novel mutation of A for G substitution at amino acid position 372 (CGG 372Arg to CAG 372Gln) was identified in one of the CTX families. The mutation was also found in two patients from the other family, with a compound heterozygous pattern of A for G substitution at amino acid position 441 (CGG 441Arg to CAG 441Gln). The latter mutation was the same as previously reported by our group (J. Lipid Res. 1994. 35: 1031-1039). As the two mutations changed the restriction enzyme sites, rapid screening methods were developed for the detection of the carriers. Transfection of the two mutant cDNAs into COS cells resulted in markedly reduced sterol 27-hydroxylase activity. These results indicate that the two mutations are responsible for the deficiency of the sterol 27-hydroxylase activity in these patients. The features of mutations identified till now in Japanese CTX patients are also reviewed.

Blood-brain barrier permeability during the development of experimental bacterial meningitis in the rat

In an attempt to examine whether routes of bacterial entry into the central nervous system have any bearing on subsequent changes in blood-brain barrier permeability, we examined cerebrospinal fluid (CSF) penetration of circulating 125I-albumin in two different models of experimental meningitis due to K1 Escherichia coli, type III group B streptococcus, or Haemophilus influenzae type b in infant rats: hematogenous meningitis subsequent to subcutaneous inoculation of bacteria vs meningitis induced by direct inoculation of bacteria into the CSF via the cisterna magna. In the model of hematogenous meningitis, the mean CSF penetration was significantly greater in animals with H. influenzae type b meningitis than in those with meningitis due to K1 E. coli or type III group B streptococcus. In contrast, the mean CSF penetration was significantly enhanced in all animals with meningitis induced by intracisternal inoculation regardless of infecting pathogens. Tumor necrosis factor activity in CSF appeared to correlate with the functional penetration of circulating albumin across the blood-brain barrier in both models of experimental meningitis. These findings suggest that the alterations of blood-brain barrier permeability during development of experimental meningitis may vary for different models of inducing meningitis and that the mechanisms responsible for these different permeability changes may be multifactorial.

A model for monocyte migration through the blood-brain barrier during HIV-1 encephalitis

HIV-1 invades the central nervous system early during viral infection, but neurologic impairment usually occurs years later. The strongest predictor for clinical dementia is the absolute numbers of immunocompetent brain macrophages. Thus, how monocytes penetrate the brain during disease remains critical for understanding the neuropathogenic mechanisms of HIV-1 encephalitis. To these ends, we constructed an artificial blood-brain barrier (BBB) consisting of a matrix-coated membrane with brain microvascular endothelial cells (BMVEC) on one side and astrocytes on the other. Astrocyte endfeet contacted the monolayer of BMVEC that formed tight junctions. To determine the role of viral and immune factors in monocyte penetration across the BBB, HIV-infected or uninfected monocytes with or without immune stimulation were placed onto the upper chamber of the BBB model system. Placement of immune-stimulated (LPS-treated) cells onto the BBB construct elicited gaps between BMVEC, with bulging of nuclear zones and increased numbers of vesicular Golgi complexes and endoplasmic reticulum. This correlated with a profound increase (up to 20-fold) in the number of migrating cells. Viral infection did not enhance monocyte migration. The activated monocytes showed increased numbers of philopodia, lysosomes, and vesicular Golgi complexes and expressed large levels of proinflammatory cytokines (TNF-alpha, IL-6, and IL-10). These data suggest that a major mechanism for the transendothelial migration of monocytes during HIV encephalitis is the immune activation that accompanies viral infection of the central nervous system.

Coronary stenting (Cordis) without anticoagulation

We evaluated the effect of antithrombotic regimens on subacute thrombosis and short-term clinical courses after successful implantation of the Cordis coronary stent, which is a flexible, balloon expandable, radiopaque tantalum stent. Two hundred seventy-five consecutive patients with 290 lesions were treated with 356 Cordis stent implantations. According to poststent antithrombotic regimen, patients were divided into 3 groups; 165 patients with 175 lesions received aspirin 200 mg/day, ticlopidine 500 mg/day, and warfarin for 1 month (group 1), 66 patients with 69 lesions received aspirin and ticlopidine (group 2), and 44 patients with 46 lesions received aspirin alone (group 3) after successful Cordis stenting. The overall procedural success rates were 97.7% in group 1, 98.6% in group 2, and 100% in group 3. More than 65% of the patients were eligible for elective stenting. The overall rate of stent thrombosis was 1.8%: 1.2% in patients assigned to the treatment with aspirin, ticlopidine, and warfarin; 0% in patients with aspirin and ticlopidine; and 6.8% in patients assigned to the treatment with aspirin alone. In conclusion, the Cordis coronary stent is an effective endovascular stent in various clinical indications including unstable angina and acute myocardial infarction. Antiplatelet therapy using aspirin and ticlopidine after successful Cordis coronary stenting is a promising alternative to anticoagulation therapy to overcome the drawbacks of stenting. However, poststent antithrombotic therapy with aspirin alone is associated with a significant rate of stent thrombosis.