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A Y Lin

Publications and source records attributed to A Y Lin.

At least 19 recordsLinked to original sources
PubMed2005

Expression of growth differentiation factor-5 and bone morphogenic protein-7 in intraocular osseous metaplasia.

BACKGROUND/AIMS: Intraocular bone is seen in a wide spectrum of ocular disorders. The pathogenetic mechanisms of bone formation in the eye are unclear. Growth differentiation factor-5 (GDF-5), bone morphogenic protein-7 (BMP-7), and transforming growth factor beta-1 (TGF beta1) are multifunctional cytokines that have important roles in bone formation. Immunohistochemistry was used to localise GDF-5, BMP-7, and TGF beta1 in the human eye to determine their role in intraocular bone formation. METHODS: Paraffin embedded sections from human eyes included fetal eyes (n = 5), normal adult eyes (n = 4), eyes with osseous metaplasia (n = 8), and eyes with focal fibrous metaplasia of the retinal pigment epithelium (RPE) without osseous metaplasia (n = 2). Immunohistochemistry was performed using indirect immunofluorescence with antibodies to GDF-5, BMP-7, and TGF beta1. The staining intensity was evaluated semiquantitatively in the RPE, retina, ciliary epithelium, and cornea; and analysed statistically. RESULTS: When compared with normal adult eyes, which showed no RPE immunoreactivity, the RPE metaplasia surrounding areas of osseous metaplasia showed mild GDF-5 and moderate BMP-7 (p = 0.004) intracytoplasmic immunoreactivity. In contrast, trace GDF-5 and mild BMP-7 staining was seen in zones of RPE fibrous metaplasia in areas not associated with osseous metaplasia. Mild intracytoplasmic TGF beta1 expression was seen in the RPE metaplasia surrounding the bone when compared with adult eyes. Both fetal and adult eyes showed trace to mild GDF-5 and BMP-7 labelling of the non-pigmented ciliary epithelium which was increased in the eyes with osseous metaplasia. In eyes with osseous metaplasia, a significant decrease in GDF-5 and BMP-7 labelling was noted in fetal keratocytes (p = 0.0159 for both antibodies) when compared to adult eyes. Also, a significant decrease in BMP-7 labelling was seen in keratocytes in eyes with osseous metaplasia (p = 0.0162). CONCLUSIONS: The increase in GDF-5, BMP-7, and TGF beta1 immunoreactivity in zones of RPE metaplasia in eyes with osseous metaplasia suggests that these proteins have an important role in intraocular ectopic bone formation.

Adult↗
PubMed2001

The development of lymphomas in families with autoimmune lymphoproliferative syndrome with germline Fas mutations and defective lymphocyte apoptosis.

Lymphomas were studied in kindreds with autoimmune lymphoproliferative syndrome (ALPS; Canale-Smith syndrome), a disorder of lymphocyte homeostasis usually associated with germline Fas mutations. Fas (CD95/APO-1) is a cell surface receptor that initiates programmed cell death, or apoptosis, of activated lymphocytes. Lymphoma phenotype was determined by immunohistochemistry, frequency of CD3(+)CD4(-)CD8(-) T-cell-receptor alpha/beta cells by flow cytometry, nucleotide sequences of the gene encoding Fas (APT1, TNFRSF6), and the percentage of lymphocytes undergoing apoptosis in vitro. Of 223 members of 39 families, 130 individuals possessed heterozygous germline Fas mutations. Eleven B-cell and T-cell lymphomas of diverse types developed in 10 individuals with mutations in 8 families, up to 48 years after lymphoproliferation was first documented. Their risk of non-Hodgkin and Hodgkin lymphomas, respectively, was 14 and 51 times greater than expected (each P <.001). Investigation of these 10 patients and their relatives with Fas mutations revealed that all had defective lymphocyte apoptosis and most had other features of ALPS. The tumor cells retained the heterozygous Fas mutations found in the peripheral blood and manifested defective Fas-mediated killing. These data implicate a role for Fas-mediated apoptosis in preventing B-cell and T-cell lymphomas. Inherited defects in receptor-mediated lymphocyte apoptosis represent a newly appreciated risk factor for lymphomas.

Adult↗
PubMed2001

Study of crystallization of endogenous surfactant in Eudragit NE30D-free films and its influence on drug-release properties of controlled-release diphenhydramine HCl pellets coated with Eudragit NE30D.

This study investigates the crystallization of the endogenous surfactant nonoxynol 100 in Eudragit NE30D-free films during storage and the influences of nonoxynol 100 on the dissolution of diphenhydramine hydrochloric acid (HCl) pellets coated with Eudragit NE30D before and after aging at ambient conditions. Polarizing light microscopy showed that when Eudragit NE30D-free films were stored at ambient conditions, off-white, flower-shaped crystals formed and increased in the polymer film as storage time increased. Also, x-ray diffraction showed polymer crystals in the aged free film. Thermogravimetric analysis showed no evidence of combined volatile molecules with the polymer molecules, and Fourier transformed infrared spectroscopy (FTIR) data suggested the same chemical composition of the polymer before and after phase separation. Further, from normal light microscopy, the appearance of the melting droplets in the polymer film indicated that the polymer molecules did not form the crystals. After the extraction of nonoxynol 100 by water, the free film formed by the water-extracted Eudragit NE30D was found free of the crystals after aging at the same conditions. The combination of the thermogravimetric analysis, FTIR, and microscopy showed that the origin of the crystals in dry Eudragit NE30D-free films came from nonoxynol 100, and not from the polymer molecules themselves. Monitoring by differential scanning calorimeter, it was found that the rates of crystallization of nonoxynol 100 were faster when the films were stored at 30 degrees C and 40 degrees C than when stored at ambient conditions and 45 degrees C. When stored at -5 degrees C, the crystallization rate was nearly zero. As the temperature got closer to melting temperature, the crystallization rate was very low because the system was in a thermodynamically disfavored state. The rate gradually increased and finally passed through a maximum as the crystallization temperature decreased. As the temperature kept decreasing, the crystallization rate became small again and eventually stopped because the system turned into a kinetically disfavored state. Because the phase transition of nonoxynol 100 in Eudragit NE30D occurred at ambient conditions, its influence on the dissolution of diphenhydramine HCl pellets coated with Eudragit NE30D was studied. Three different levels of nonoxynol 100 were used in Eudragit NE30D dispersions to make 3 different batches of Eudragit NE30D film-coated, controlled-release diphenhydramine HCl pellets. The results showed the dissolution rate increased as the level of nonoxynol 100 increased in the coating formula. Compared to the commonly used water-soluble additive human peripheral mononuclear cell, nonoxynol 100 was more effective in enhancing the dissolution of diphenhydramine HCl from pellets coated with Eudragit NE30D. Further study showed that the phase separation of the surfactant during aging tends to stabilize or slightly increase dissolution rates at higher surfactant levels.

Acrylates↗
PubMed2001

Amphotericin B--not so terrible.

OBJECTIVE: To describe a patient who developed adverse reactions to two different lipid formulations of amphotericin B: liposomal amphotericin B (AmBisome) and amphotericin B colloidal dispersion (ABCD, Amphocil), yet tolerated amphotericin B deoxycholate (Fungizone) despite renal toxicity. CASE SUMMARY: A 72-year-old woman with acute myelomonocytic leukemia was treated with amphotericin B deoxycholate for suspected pulmonary aspergillosis; the drug was well tolerated but resulted in renal failure. Antifungal therapy was then changed to liposomal amphotericin B. Within 10 minutes of liposomal amphotericin B infusion, the patient developed severe dyspnea, chest pain, and a feeling of imminent death. On the following day, liposomal amphotericin B was switched to amphotericin B colloidal dispersion. Again, within 10 minutes of this infusion, the patient developed fever, chills, hypotension, severe chest pain, dsypnea, and a feeling of imminent death. The patient refused any further treatment with these drugs and insisted on switching back to amphotericin B deoxycholate, which was then administered for 10 days and was well tolerated. DISCUSSION: Severe adverse reactions, such as anaphylaxis, cardiac toxicity, and respiratory failure, following administration of all three lipid formulations of amphotericin B have been reported. In most reported cases, switching to a different lipid formulation of amphotericin B was well tolerated. This is in contrast to our case, where a severe reaction was repeated when another lipid preparation was given, necessitating switching back to amphotericin B deoxycholate despite its nephrotoxicity. CONCLUSIONS: In some patients, paradoxically, lipid formulations of amphotericin B may be less tolerable than conventional amphotericin B.

Acute Kidney Injury↗
PubMed1998

Familial eosinophilia: clinical and laboratory results on a U.S. kindred.

We describe a five-generation kindred with familial eosinophilia (FE; MIM131400), characterized by the occurrence of sustained eosinophilia of unidentifiable cause in multiple relatives. The inheritance pattern is consistent with an autosomal dominant pattern. Among 52 related subjects studied, 19 were affected and 33 were unaffected. Ten unaffected spouses were also evaluated. Four subjects with sustained eosinophilia were diagnosed with cardiac abnormalities and two of them also had neurologic symptoms. In comparison with the unaffected or spouses, evaluation of complete blood counts showed that the affected relatives had, as expected, significantly higher white cell (P < 0.005) and absolute eosinophil counts (P < 0.001) and lower red cell counts (P < 0.05). Evaluation of serum cytokine levels (IL-5, IL-3, and granulocyte-macrophage colony-stimulating factor (GMCSF) and serology for parasitic helminth infection demonstrated no differences between the affected and unaffected individuals; no individuals studied had serologic evidence for parasitic infection. There were also no differences in anti-nuclear antibody, serum cobalamin (vitamin B12) level, immunoglobulin level, leukocyte alkaline phosphatase, rheumatoid factor, HLA analysis, and stool findings for ova and parasites. Among eight affected persons who had peripheral blood or bone marrow karyotype analysis, two carried the same chromosome abnormality, a pericentric inversion of chromosome 10, inv (10) (p11.2q21.2). A gene mapping study is currently underway to study the underlying genetic mechanism(s) of this syndrome.

Adolescent↗
PubMed1998

Allelic imbalance, including deletion of PTEN/MMACI, at the Cowden disease locus on 10q22-23, in hamartomas from patients with Cowden syndrome and germline PTEN mutation.

Cowden disease (CD) is a rare, autosomal dominant inherited cancer syndrome characterized by multiple benign and malignant lesions in a wide spectrum of tissues. While individuals with CD have an increased risk of breast and thyroid neoplasms, the primary features of CD are hamartomas. The gene for CD has been mapped by linkage analysis to a 6 cM region on the long arm of chromosome 10 at 10q22-23. Loss of heterozygosity (LOH) studies of sporadic follicular thyroid adenomas and carcinomas, both component tumors of CD, have suggested that the putative susceptibility gene for CD is a tumor suppressor gene. Somatic missense and nonsense mutations have recently been identified in breast, prostate, and brain tumor cell lines in a gene encoding a dual specificity phosphatase, PTEN/MMACI, mapped at 10q23.3. Furthermore, germline PTEN/MMACI mutations are associated with CD. In the present study, 20 hamartomas from 11 individuals belonging to ten unrelated families with CD have been examined for LOH of markers flanking and within PTEN/MMACI. Eight of these ten families have germline PTEN/MMACI mutations. LOH involving microsatellite markers within the CD interval, and including PTEN/MMACI, was identified in two fibroadenomas of the breast, a thyroid adenoma, and a pulmonary hamartoma belonging to 3 to 11 (27%) of these patients. The wild-type allele was lost in these hamartomas. Semi-quantitative PCR performed on RNA from hamartomas from three different tissues from a CD patient suggested substantial reduction of PTEN/MMACI RNA levels in all of these tissues. The LOH identified in samples from individuals with CD and the suggestion of allelic loss and reduced transcription in hamartomas from a CD patient provide evidence that PTEN/MMACI functions as a tumor suppressor in CD.

Chromosomes, Human, Pair 10↗
PubMed1998

TGF-beta2 inhibits growth of uveal melanocytes at physiological concentrations.

The effect of TGF-beta2 on growth of uveal melanocytes in vitro was studied and the dose-dependent inhibitory effect of TGF-beta2 was compared with the known concentration of TGF-beta2 in aqueous humor. Uveal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor. The uveal melanocytes were plated into multi-well plates. After 24 hr, TGF-beta2 was added to the medium in various concentrations. After 5 days, the cells were detached, counted and compared to the controls. The effect of TGF-beta2 on DNA synthesis (as evaluated by uptake of bromodeoxyuridine) were also tested. TGF-beta2 inhibited growth and DNA synthesis of cultured uveal melanocytes in a dose-dependent manner at concentrations from 0.03-10.0 ng ml-1. The growth-inhibition of TGF-beta2 was present even in serum-free medium. TGF-beta2 had little or no effect on melanogenesis of cultured uveal melanocytes. The serum used for cultivation did not contain active TGF-beta1 or TGF-beta2 as measured by immunoassay. The known amount of active TGF-beta2 in aqueous humor (0.2-0.4 ng ml-1) is sufficient to inhibit the growth of uveal melanocytes. It indicates that TGF-beta2 is a potent growth inhibit factor of uveal melanocytes and may play an important role in maintaining the non-proliferative, relatively quiescence status of uveal melanocytes in vivo.

Adult↗
PubMed1998

Pathological findings in human autoimmune lymphoproliferative syndrome.

The defects in lymphocyte apoptosis that underlie the autoimmune lymphoproliferative syndrome (ALPS) are usually attributable to inherited mutations of the CD95 (Fas) gene. In this report, we present the histopathological and immunophenotypic features seen in the lymph nodes (n = 16), peripheral blood (n = 10), bone marrow (n = 2), spleen (n = 3), and liver (n = 2) from 10 patients with ALPS. Lymph nodes showed marked paracortical hyperplasia. Interfollicular areas were expanded and populated by T cell receptor-alphabeta CD3+ CD4-CD8- (double-negative, DN) T cells that were negative for CD45RO. CD45RA+ T cells were increased in all cases studied. The paracortical infiltrate was a result of both reduced apoptosis and increased proliferation, as measured by in situ detection of DNA fragmentation and staining with MIB-1, respectively. The paracortical proliferation may be extensive enough to suggest a diagnosis of malignant lymphoma. Many of the paracortical lymphocytes expressed markers associated with cytotoxicity, such as perforin, TIA-1, and CD57. CD25 was negative. In addition, most lymph nodes exhibited florid follicular hyperplasia, often with focal progressive transformation of germinal centers; in some cases, follicular involution was seen. A polyclonal plasmacytosis also was present. The spleens were markedly enlarged, more than 10 times normal size. There was expansion of both white pulp and red pulp, with increased DN T cells. DN T cells also were observed in liver biopsies exhibiting portal triaditis. In the peripheral blood, the T cells showed increased expression of HLA-DR and CD57 but not CD25. CD45RA+ T cells were increased in the four cases studied. Polyclonal B cell lymphocytosis with expansion of CD5+ B cells was a characteristic finding. Taken together, the histopathological and immunophenotypic findings, particularly in lymph nodes and peripheral blood, are sufficiently distinctive to suggest a diagnosis of ALPS. Of note, two affected family members of one proband developed lymphoma (T-cell-rich B-cell lymphoma and nodular lymphocyte predominance Hodgkin's disease, respectively).

Apoptosis↗
PubMed1998

Familial eosinophilia maps to the cytokine gene cluster on human chromosomal region 5q31-q33.

Familial eosinophilia (FE) is an autosomal dominant disorder characterized by peripheral hypereosinophilia of unidentifiable cause with or without other organ involvement. To localize the gene for FE, we performed a genomewide search in a large U.S. kindred, using 312 different polymorphic markers. Seventeen affected subjects, 28 unaffected bloodline relatives, and 8 spouses were genotyped. The initial linkage results from the genome scan provided evidence for linkage on chromosome 5q31-q33. Additional genotyping of genetic markers located in this specific region demonstrated significant evidence that the FE locus is situated between the chromosome 5q markers D5S642 and D5S816 (multipoint LOD score of 6.49). Notably, this region contains the cytokine gene cluster, which includes three genes-namely, those for interleukin (IL)-3, IL-5, and granulocyte/macrophage colony-stimulating factor (GM-CSF)-whose products play important roles in the development and proliferation of eosinophils. These three cytokine genes were screened for potential disease-specific mutations by resequencing of a subgroup of individuals from the present kindred. No functional sequence polymorphisms were found within the promoter, the exons, or the introns of any of these genes or within the IL-3/GM-CSF enhancer, suggesting that the primary defect in FE is not caused by a mutation in any one of these genes but, rather, is caused by another gene in the area.

Adolescent↗
PubMed1998

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation.

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.

Chromosome Mapping↗
PubMed1997

Regulation of melanogenesis by human uveal melanocytes in vitro.

The purpose of this study was to investigate factors regulating melanogenesis in cultured human uveal melanocytes. The effects of various substances on the melanin content, tyrosinase activity and growth of cultured uveal melanocytes were tested. 12-O-tetradecanoyl-phorbol-13-acetate (a protein kinase C activator) and various cAMP-elevating agents, including isobutylmethylxanthine, cholera, toxin, and dibutyryl-cAMP increased melanin content per culture, tyrosinase activity and cell numbers of uveal melanocytes in a dose dependent manner. Basic fibroblast growth factor (tyrosine kinase activator) stimulated growth but did not affect melanin content per culture of uveal melanocytes in vitro. These results indicate that cAMP-elevating agents and protein kinase C activator stimulate melanogenesis and growth of cultured uveal melanocytes. Tyrosine kinase activator stimulates growth but not melanogenesis of cultured uveal melanocytes.

Adult↗
PubMed1996

Epstein-Barr virus and familial Hodgkin's disease.

Several studies suggest that the Epstein-Barr virus (EBV) is etiologically linked to Hodgkin's disease (HD). This study was undertaken to examine the role of EBV in familial HD (FHD). Among 60 FHD patients from 27 families with two or more cases per family, we tested available paraffinized tumor tissues from 46 cases by in situ hybridization for EBV-encoded RNA (EBER1) expression. Thirteen of 46 FHD patients (28%) had EBER1 expressed in the Reed-Sternberg cells. Concordance rate of EBV positivity was evaluated among 34 first-degree related pairs from 17 families for which both cases had available paraffinized tumor tissues. Only two of 17 pairs were concordant for EBER1 positivity. There was no excess of positive concordance (P = .18). Serologically, FHD patients had higher geometric mean antibody titers (GMTs) to the viral capsid antigen (VCA) and early antigen D (EA-D). There was no difference in seroprevalence between patients and control groups, nor was there concordance in elevated serology among 15 pairs of first-degree related FHD cases. Young adult unaffected family members (UFM) may not react to EBV in the same way as the general population as evidenced by the lower titer of VCA, although not statistically significant, and significantly lower titers of EA-D, compared with age-matched controls. While EBV might have some role in a subset of HD, lack of concordance of EBER1 expression and EBV serology among the FHD cases in the same family suggest that EBV does not play an important role in FHD.

Adolescent↗
PubMed1996

NADPH-diaphorase histochemistry of rat choroid plexus blood vessels and epithelium.

Choroid plexus is the major source of cerebrospinal fluid. The hemodynamics and secretory function of this tissue are controlled by multiple endocrine and neural mechanisms. Nitric oxide (NO) has been demonstrated to play an important role in regulating choroidal blood flow. In the present study, performed on adult male Sprague-Dawley rats, we employed a NADPH-diaphorase (NADPH-d) histochemical method to localize nitrergic innervation of choroidal blood vessels. This approach was based on previous observations that NADPH-d colocalizes with NO synthase, a synthetic enzyme for NO, in the central and peripheral nervous systems. NADPH-d-positive nerve fibers were found to accompany both large arteries and veins and blood microvessels (possibly arterioles) located in choroidal stroma. NADPH-d reaction product was also localized to the vascular endothelial lining and choroidal epithelial cells. All the above sources of NO may play important roles in the regulation of secretory and hemodynamic functions of the choroid plexus.

Animals↗
PubMed1996

Absence of germline p53 mutations in familial lymphoma.

p53, a tumor suppressor gene, is frequently mutated in sporadic human cancer, and inherited mutations in p53 predispose to the early onset of cancer. p53 mutations occur frequently in sporadic lymphoma, and, in mice deficient for p53, lymphoma is the most common type of malignancy. Families with an increased incidence of lymphoma have been described, suggesting an inherited predisposition to lymphoma in these circumstances. To determine whether the predisposition to lymphoma in these families results from germline mutations in p53, we analysed exons 4-11 of the p53 gene in 35 individuals from 19 lymphoma-prone kindreds. We found no germline p53 mutations in any of the individuals tested. However, p53 expression assessed by immunohistochemistry, which suggests mutation, was observed in 35% of the tumor samples from the familial Hodgkin's disease cases and in 13% of the familial non-Hodgkin's lymphoma cases. These results suggest that p53 mutations do not play a critical role in heritable susceptibility to lymphoma. p53 may act by different, non-mutation related mechanisms in this setting, or be involved in late events in the pathogenesis of these tumors.

Adolescent↗
PubMed1996

Beta cap73: a novel beta actin-specific binding protein.

Whereas actin-binding proteins (ABPs) regulate network formation during the cell cycle, it is not known whether ABPs also function to sequester or target isoactins to specific subcellular compartments. Recently, we have shown that ezrin indirectly associates with beta, but not alpha actin filaments in a calcium- and cytochalasin-sensitive manner [Shuster and Herman, 1995: J. Cell Biol. 128:837-848]. To identify the beta actin-specific binding protein that fosters ezrin-beta actin interactions, we developed an isoactin affinity fractionation and F-isoactin overlay/Western blotting technique. Results reveal that a 73 kd polypeptide that co-precipitates with ezrin and beta actin [Shuster and Herman, 1995: J. Cell Biol. 128:837-848] can also binds directly to filaments of beta, but not alpha actin by isoactin overlay. In an effort to establish whether p73 plays a role in regulating beta actin dynamics in cells, we produced monoclonal antibodies by immunizing BALB/c mice with p73-containing lamellar lysates or high salt elutions from beta actin affinity columns. Two monoclonal antibodies were cloned that react with p73 present in fractions released from beta actin Sepharose-4B or purified to homogeneity by DEAE chromatography. Anti-p73 Western blots reveal that there is a 16-fold difference in p73 binding to beta actin vs. alpha actin affinity columns when experiments are performed in physiological salts. To characterize p73-beta actin binding in vitro and establish whether p73 binds along the lengths or at the barbed end of the beta actin filament, we asked whether cytochalasin D (CD) could displace p73 pre-bound to beta actin-Sepharose 4B. Anti-p73 Western blotting reveals that nanomolar concentrations of CD are capable of selectively eluting p73 and ezrin from beta actin Sepharose 4B, indicating that p73 binds beta actin via the barbed end. Simultaneous double antibody localization studies using anti-beta actin IgG and anti-p73 IgM reveal that p73 and beta actin are co-localized in the forward aspects of motile cytoplasmic domains, in close proximity to the plasma membrane. Because of its isoform-specific interactions with the barbed end of beta actin filaments, we have named this molecule beta cap73. These results indicate that isoform-specific actin-binding proteins can be identified from cortical cytoplasm, and suggest that beta cap73 may not only act to spatially regulate the intracellular distribution of isoactins, but may also facilitate forward protrusion formation through the regulated release of free filament ends during cell motility.

Actins↗
PubMed1996

Immunohistochemical localization of nitric oxide synthase in rat anterior choroidal artery, stromal blood microvessels, and choroid plexus epithelial cells.

Nitric oxide (NO) has recently been shown to regulate blood flow to choroid plexus, a specialized brain structure responsible for production of most of cerebrospinal fluid. In the present study, we used a specific polyclonal rabbit antibody against the neuronal isoform of NO synthase (NOS), a synthetic enzyme for NO, to determine the localization of NOS in the choroid plexus of adult male Sprague-Dawley rats. NOS-containing nerve fibers were found in the anterior choroidal artery and its branches, and in stromal blood microvessels. Chronic denervation experiments indicated that these nerve fibers originate predominantly from the sphenopalatine ganglion. NOS-immunopositive staining was also detected in the cytoplasm of choroidal epithelial cells. NADPH-diaphorase, a histochemical marker for NOS, was found to colocalize with NOS-immunoreactive product in both nerve fibers and choroidal epithelium. Both neuronal and epithelium-derived NO may regulate secretory function and hemodynamics of choroidal tissue.

Animals↗