HydroCoil occlusion for treatment of traumatic carotid-cavernous fistula: preliminary experience

OBJECTIVE

To summarize our preliminary experiences regarding HydroCoil occlusion for the treatment of carotid-cavernous fistula (CCF), and to evaluate the effectiveness of this treatment.

METHODS

From January 2006 to June 2007, 15 patients with traumatic CCF who were treated using HydroCoil occlusion were included in this study. All the patients presented with symptoms such as intracranial pulsatile noise, bulbar conjunctival hyperemia, and pulsatile exophthalmia. Cerebral angiography revealed that the fistula was located in the right internal carotid-cavernous segment in 6 cases, in the left internal carotid-cavernous segment in 8 cases, and on both sides in 1 case.

RESULTS

After CCF procedure, in 15 patients, the fistula was no longer visualized, the internal carotid artery on the affected side remained patent, and intracranial noise disappeared immediately. The preoperative symptoms exophthalmia, bulbar conjunctival hyperemia, etc., returned to normal 1 week after the operation. Vision recovered to varying extents. In the 9 patients who underwent 1-3 months of follow-up cerebral angiography, CCF recurrences and neurological complications were not observed.

CONCLUSION

Intravascular occlusion has been widely used for CCF treatment, and detachable balloon embolization remains the preferred treatment. In the case of failure of detachable balloon embolization because the patient cannot tolerate the procedure or internal carotid artery occlusion on the affected side is contraindicated, HydroCoil occlusion is a safe and effective though expensive alternative and a stable method of maintaining high carotid artery patency.

Identification of a novel HLA-A allele, HLA-A*9216

The new human leukocyte antigen (HLA)-A*9216 differs from A*02010101 by a nonsynonymous nucleotide change at condon 76 (GTG>CTG).

Concordant expression of proto-oncogene promyelocytic leukemia and major histocompatibility antigen HLA class I in human hepatocellular carcinoma

Many malignant cancer cells downregulate human leukocyte antigen (HLA) class I antigen expression to evade T cell recognition. However, hepatocellular carcinoma (HCC) is exceptional to the general findings in cancer cells, and the mechanisms for its upregulation remain unclear. It has been reported that promyelocytic leukemia (PML) proto-oncogene controls the transcription of multiple class I antigen presentation genes in murine cancer cells. To find out the functional role of PML gene on the increased HLA class I antigen expression in HCC cells, we analyzed the expression of proto-oncogene PML and multiple class I antigen presentation genes in HCC specimens obtained in China. The results showed concordant changes of proto-oncogene PML and cell surface HLA-A expression in 44 paraffin-embedded HCC tissues. Furthermore, co-upregulated expression of PML genes and class I antigen presentation genes could be detected in 9 of 15 fresh HCC tissues by reverse transcription polymerase chain reaction (RT-PCR). In addition, studies using HCC cell lines showed that increased expression of HLA class I molecules paralleled with PML upregulation were detected in QGY-7701 HCC cell line with RT-PCR, western blot, and flow cytometry, and that the overexpression of exogenous PML in a low-expression class I cell line BEL-7405 could induce the expression of multiple class I antigen-presenting molecule genes and slightly but significantly increase the expression of cell surface HLA class I molecules. In conclusion, the expression of proto-oncogene PML and HLA class I molecules were concordantly upregulated and the expression of PML gene might be one of the mechanisms that leads to the increased expression of class I antigen in HCC.

Enhanced photoelectrocatalytic performance of Zn-doped WO(3) photocatalysts for nitrite ions degradation under visible light

WO(3) and Zn-doped WO(3) thin films were prepared on indium-tin oxide glass by a dip-coating. The composite films were characterized by UV-Vis absorption spectra, X-ray diffraction and scanning electron microscope. The effect of preparation conditions (concentration of Zn, annealing temperature, number of layers) on the photocurrent was studied. It was found that the photocurrent under visible light displayed the highest value for 2% Zn-WO(3) films annealed at 400 degrees C. The photocatalytic activity of the Zn-doped WO(3) was evaluated in terms of decay rate of nitrite ions under visible light. The influence of applied potential, initial pH and nitrite concentration on the reaction rate was studied. The experiments demonstrated that NO(2)(-) could be efficiently degraded on the doped photoanode that showed a higher activity than the undoped WO(3) especially under high anodic potential (>0.7 V). The rate of degradation was enhanced in aqueous NaCl solutions. Furthermore, it was demonstrated that the photodegradation mechanism of NO(2)(-) proceeded mainly indirectly via OH radicals. The possible reason of enhancement of reaction rate was also discussed.

Parallel sequential minimal optimization for the training of support vector machines

Sequential minimal optimization (SMO) is one popular algorithm for training support vector machine (SVM), but it still requires a large amount of computation time for solving large size problems. This paper proposes one parallel implementation of SMO for training SVM. The parallel SMO is developed using message passing interface (MPI). Specifically, the parallel SMO first partitions the entire training data set into smaller subsets and then simultaneously runs multiple CPU processors to deal with each of the partitioned data sets. Experiments show that there is great speedup on the adult data set and the Mixing National Institute of Standard and Technology (MNIST) data set when many processors are used. There are also satisfactory results on the Web data set.

A soluble truncated cadherin induces breast cancer cell apoptosis and growth inhibition

PURPOSE

To identify the characteristics and function of the truncated cadherin cDNA which encodes a soluble molecule containing the sequence of VE-cadherin extracellular domain repeats from repeat 1 to 4 (designated as CED1-4) and a secreting signal peptide at N terminal.

METHODS

A pMSCV/CED1-4 vector was constructed. Recombinant retrovirus ReCED1-4 and ReEmpty were produced by 293 package cells and transfected into MDA-MB435 human breast cancer cells. The expression of CED1-4 in transfectants and their supernatant was analyzed by RT-PCR and Western blot, respectively. MDA-MB435 cell proliferation assays were performed in vitro and in vivo. CED-14-induced apoptosis was demonstrated using Annexin V binding, TUNEL and caspase 3 assays. The expression of integrin beta1 and c-fos mRNA was detected by RT-PCR.

RESULTS

The constructed soluble CED1-4 encoded 484 amino acids and a secreting signal peptide (27 amino acids). CED1-4 was expressed by MDA-MB435/CED1-4 cells, and detected in the supernatant of CED1-4 tranfectants. CED1-4 transfection significantly inhibited the growth of MDA-MB435 cells in vitro and in vivo. About 22-fold increase in the early apoptotic cells in MDA-MB435/CED1-4 cells was observed as compared with MDA-MB435/empty cells. Increased activity of caspase 3 in MDA-MB435/CED1-4 cells was more than two times as compared with that of the control cells. Interestingly, integrin beta1 transcriptional level in MDA-MB435/CED1-4 cells was down-regulated as compared with control cells. The resistance of fibronectin to CED1-4 apoptotic inducibility was confirmed by detection of caspase 3. The blockage of c-fos transcriptional expression was detected in MDA-MB435/CED1-4 cells.

CONCLUSIONS

The soluble truncated cadherin may be considered an apoptotic inducer and growth inhibitor in the MDA-MB435 breast carcinoma cell line. Down-regulation of integrin beta1 and blockage of c-fos expression may be related to CED1-4-induced apoptosis and growth inhibition.

Loss of heterozygosity at 6p21.3 underlying HLA class I downregulation in gastric cancer

Human major histocompatibility complex (HLA), located on 6p21.3, encodes for genes involved in antigen processing and presentation. Loss of heterozygosity (LOH) at 6p21.3 may cause downregulated expression of HLA, thus provide tumor cells with an immune-escape tumor phenotype. In the present study, we detected HLA class I expression in gastric cancer and correlated it with LOH at 6p21.3. The expression of HLA class I antigen was analyzed by immunohistochemical procedure in 50 fresh surgically removed gastric cancers and corresponding normal tissues using 5 monoclonal antibodies (mAbs). LOH studies were detected by using 6 microsatellite markers located at 6p21.3, 1 marker located at 6q21 and 2 microsatellite markers flanking the beta2m gene. HLA class I complex was obviously downregulated in gastric cancer compared with corresponding normal tissues (t=4.00, p<0.01). The expression of beta2m gene was also downregulated in tumor, but not concordant with HLA class I surface downregulation. Out of the 50 tumors, 25 (50%) showed LOH of at least one STR marker at 6p21.3 while only 11 (22%) showed LOH of the two markers flanking the beta2m gene. The LOH frequency of D6S105, which is close to HLA-A gene, was the highest in all STR markers studied (34%). Downregulation of HLA class I expression was correlated with loss of chromosomal regions at 6p21.3 (chi-squared = 5.13, p<0.05). Our results suggested that LOH of 6p21.3 contributed to HLA class I downregulated expression in gastric cancer especially at HLA-A locus. LOH of HLA-A gene might be one of the mechanisms underlying the abnormal expression of HLA class I complex.

Investigation of the Kinetics of a TiO2 Photoelectrocatalytic Reaction Involving Charge Transfer and Recombination through Surface States by Electrochemical Impedance Spectroscopy

In this paper, the electrochemical impedance spectroscopy (EIS) mathematical model of TiO2 photoelectrocatalytic (PEC) reactions involving charge transfer and recombination through surface states was developed. The model was used to study the kinetics of photoelectrocatalytic decomposition of salicylic acid. The model simulation results show that the appearance of two distinguishable semicircles in the EIS response depends on the charging of surface state and light intensity. The experimental results demonstrated that similar phenomena to the theoretical simulation results. The model provides a way to obtain the rate constants for the photoelectrochemical reactions of surface states mediating charge transfer and recombination. The applied potential changes not only the recombination rate constant but also the charge-transfer rate constant. Moreover, the experimental EIS results here and those previous published on PEC degradation reactions can be explained by the present model satisfactorily. The relevance of surface states was discussed briefly. The results demonstrated that EIS is a powerful tool for studying the kinetics of PEC decomposition of organic pollutants on TiO2 electrodes.

Lyophilized Paclitaxel Magnetoliposomes as a Potential Drug Delivery System for Breast Carcinoma via Parenteral Administration: In Vitro and in Vivo Studies

PURPOSE

The study reports in vitro and biological evaluation of lyophilized negatively charged paclitaxel magnetic liposomes as a potential carrier for breast carcinoma via parenteral administration.

METHODS

Paclitaxel in magnetoliposomes were extracted by centrifugation and quantified by high-performance liquid chromatography (HPLC). Biological properties were studied using pharmacokinetics, in vivo distribution and cytotoxicity assays, as well as a mouse model of EMT-6 breast cancer.

METHODS

Pharmacokinetic studies showed that encapsulation of paclitaxel in magnetoliposomes produced marked difference over the drug in Cremophor EL/ethanol pharmacokinetics, with an increased t(1/2beta) 19.37 h against 4.11 h. For in vivo distribution, paclitaxel concentration of lyophilized magnetoliposomes in the tumor was much higher than that of lyophilized conventional liposomes or Cremophor EL/ethanol, whereas in heart it was much lower than the latter two formulations via s.c. and i.v. administration. Lyophilized paclitaxel magnetic liposomes showed more potency on the therapy of breast cancer than other formulations via s.c. and i.p. administration.

CONCLUSIONS

The current study demonstrates that paclitaxel magnetoliposomes can effectively be delivered to tumor and exert a significant anticancer activity with fewer side effects in the xenograft model.

Lung-targeting microspheres of carboplatin

Carboplatin (CPt) was incorporated in the gelatin microspheres by the method of emulsion and the drug content determined spectrophotometrically. The arithmetic mean diameter of the microspheres was 13.20 microm with 98% of the microspheres ranging from 5.0 to 28.6 microm. The average carboplatin content was 23.76% and the yield of the microspheres 85.12%. The microspheres were stable for three months when stored at 37 degrees C/RH 75%, showing insignificant change in appearance and drug content. The in vitro release profile of the microspheres could be described by a biexponential equation, and the release t(1/2) was 49.7 min and 92.04% released in 10h; while for the original drug, CPt, under the same conditions, 92.15% released in the first half an hour. Very high lung-targeting efficiency in vivo was proved by the results of targeting parameters. The S-180 lung neoplasm models were established by i.v. cancer cells in mice and the number of pulmonary nodules examined for evaluation of the treatment effect. The results of therapeutic tests showed that the antitumour effects were increased by injection of the microspheres compared with the injection of CPt solution: half of the dose in the microspheres showed comparable effect to the original drug.

Nonphospholipid vesicles of Carboplatin for lung targeting

Carboplatin (CPt) was incorporated into nonphospholipid vesicles (NPLV) by the method of membrane dispersion and its content determined spectrophotometrically. The particle size was between 2.0-10.0 microm with a mean value of 3.26 microm and a span of 0.55; and the drug content was 3.965 mg/ml. Dynamic dialysis was used for in vitro release of CPt and the results indicated that the drug release t(1/2) was increased eight times, compared with the original drug. These parameters had little change after lyophilization. When tested with mice, the body distribution parameters showed obviously lung targeting characteristics. The S-180 lung neoplasm models were established by intravenous cancer cells in mice and the number of pulmonary nodules examined for evaluation of the therapeutic efficacy. Antitumor effect was increased and differed significantly (p <.05) compared with the original drug of the same dose.

Ultrastructural and biochemical localization of N-RAP at the interface between myofibrils and intercalated disks in the mouse heart

N-RAP is a recently discovered muscle-specific protein found at cardiac intercalated disks. Double immunogold labeling of mouse cardiac muscle reveals that vinculin is located immediately adjacent to the fascia adherens region of the intercalated disk membrane, while N-RAP extends approximately 100 nm further toward the interior of the cell. We partially purified cardiac intercalated disks using low- and high-salt extractions followed by density gradient centrifugation. Immunoblots show that this preparation is highly enriched in desmin and junctional proteins, including N-RAP, talin, vinculin, beta1-integrin, N-cadherin, and connexin 43. Electron microscopy and immunolabeling demonstrate that N-RAP and vinculin are associated with the large fragments of intercalated disks that are present in this preparation, which also contains numerous membrane vesicles. Detergent treatment of the partially purified intercalated disks removed the membrane vesicles and extracted vinculin and beta1-integrin. Further separation on a sucrose gradient removed residual actin and myosin and yielded a fraction morphologically similar to fasciae adherentes that was highly enriched in N-RAP, N-cadherin, connexin 43, talin, desmin, and alpha-actinin. The finding that N-RAP copurifies with detergent-extracted intercalated disk fragments even though beta-integrin and vinculin have been completely removed suggests that N-RAP association with the adherens junction region is mediated by the cadherin system. Consistent with this hypothesis, we found that recombinant N-RAP fragments bind alpha-actinin in a gel overlay assay. In addition, immunofluorescence shows that N-RAP remains bound at the ends of isolated, detergent-treated cardiac myofibrils. These results demonstrate that N-RAP remains tightly bound to myofibrils and fasciae adherentes during biochemical purification and may be a key constituent in the mechanical link between these two structures.

Renin expression at sites of repair in the infarcted rat heart

Y. Sun, J. Zhang, J. Q. Zhang and K. T. Weber. Renin Expression at Sites of Repair in the Infarcted Rat Heart. Journal of Molecular and Cellular Cardiology (2001) 33, 995-1003. Angiotensin (Ang) II has autocrine and paracrine functions that contribute to structural cardiac remodeling by fibrous tissue following myocardial infarction (MI). The recruitment of angiotensin converting enzyme (ACE) and AngII receptors by inflammatory and fibroblast-like cells involved in tissue repair of the infarcted heart is now well established. On the other hand, the temporal and spatial response and cellular source of renin in infarcted hearts have not been fully elucidated. The relationship between renin synthesis and circulating renin activity have likewise not been addressed. The present study sought to assess the cellular source, spatial distribution and temporal response of renin expression and synthesis in the rat heart following anterior transmural MI, and to determine its relationship to circulating renin activity. At day 3 and weeks 1, 2, 3 and 4 following left coronary artery ligation, the localization and optical density of cardiac renin mRNA was detected by quantitative in situ hybridization; cardiac and circulating renin activity was measured by radioimmunoassay; cells expressing cardiac renin were detected by immunohistochemistry; and injury/repair was assessed by hematoxylin/eosin and collagen-specific picrosirius red staining. Unoperated rats served as normal controls. The authors found: (1) renin mRNA and activity were not detected in either normal control or non-infarcted myocardium, but were expressed at the site of infarction and other sites of repair involving visceral pericardium and endocardium of interventricular septum at all time points; (2) cells expressing renin at day 3 and weeks 1 and 2 were predominantly macrophages, while at weeks 3 and 4, they were primarily myofibroblasts; (3) renin activity in the infarcted myocardium rose progressively over the course of 4 weeks; and (4) circulating renin activity was significantly increased at day 3 and week 1, reached a peak at week 2, declined at week 3 and returned to normal levels at week 4. Thus, renin expression and activity appear at sites of repair in the infarcted rat heart on day 3 and rise progressively thereafter over 4 weeks, independent of circulating renin. Several types of cells are responsible for renin synthesis at these sites; primarily macrophages during the inflammatory phase of repair, and myofibroblasts during the subsequent fibrogenic phase. Cardiac renin production following MI contributes to local AngII generation that regulates tissue repair and structural remodeling following MI.

Topography and distribution of sympathetic nerve fibers in the rat temporomandibular joint: immunocytochemistry and ultrastructure

The distribution and fine structure of nerve fibers containing neuropeptide Y (NPY), tyrosine hydroxylase (TH), and vasoactive intestinal polypeptide (VIP) in the temporomandibular joint were investigated by both the avidin-biotin complex method and an indirect immunofluorescence technique. The innervation pattern of NPY- and TH-positive fibers differed from that of VIP-positive fibers. Specifically, the former was distributed in both the superficial and deep sublining layers, while the latter was mostly located in the deep sublining layer. NPY- and TH-immunoreactive fibers were largely confined to vascular elements; occasional fibers were observed in the synovial lining layer close to the joint cavity. More nerves with NPY and TH immunoreactivity were observed close to the upper joint compartment than near the lower compartment NPY and TH immunoreactivity was dramatically reduced in the TMJ of superior cervical ganglionectomized animals, indicating the sympathetic origin of these nerves. NPY immunoreactivity was found only in unmyelinated axons, which were located in the adventitia and adventitia-medial border of arteries or arterioles. Occasionally, axons were near the joint cavity, in areas free of vascular structures. These observations show that abundant sympathetic nerves supply the temporomandibular joint of the rat and provide a morphological basis for the involvement of different neuropeptides in vascular regulatory and modulatory functions in physiological and pathophysiological conditions.

Identification, characterization and leucocyte expression of Siglec-10, a novel human sialic acid-binding receptor

Here we characterize Siglec-10 as a new member of the Siglec family of sialic acid-binding Ig-like lectins. A full-length cDNA was isolated from a human spleen library and the corresponding gene identified. Siglec-10 is predicted to contain five extracellular Ig-like domains and a cytoplasmic tail containing three putative tyrosine-based signalling motifs. Siglec-10 exhibited a high degree of sequence similarity to CD33-related Siglecs and mapped to the same region, on chromosome 19q13.3. The expressed protein was able to mediate sialic acid-dependent binding to human erythrocytes and soluble sialoglycoconjugates. Using specific antibodies, Siglec-10 was detected on subsets of human leucocytes including eosinophils, monocytes and a minor population of natural killer-like cells. The molecular properties and expression pattern suggest that Siglec-10 may function as an inhibitory receptor within the innate immune system.

[A review of brain aromatase]

Aromatase catalyzes the conversion of androgen to estrogen. This enzyme has been primarily localized in the neurons of specific areas of limbic system and hypothalamus of the brain. Astrocytes may also express this enzyme. Studies show that the gene expression of aromatase is driven by multiple tissue-specific exons, and the effective concentration of brain estrogen depends on the expression of brain aromatase. The locally produced estrogen plays an important role in the regulation of synaptogenesis, density of dendritic spine and the expression of neurotrophic factors and/or their receptors. Estrogen can also protect brain cells from the damages of neurotoxins and can greatly improve the deficits of learning and memory resulted from neurodegenerative disorders such as Alzheimer's diseases.

[Studies on lung targeted niosomes of carboplatin]

AIM

To improve the treatment efficacy and reduce the side effect of carboplatin (CBP), the antitumor drug was incorporated into niosomes (NS).

METHODS

Lung targeted niosomes of CBP (CBP-NS) were prepared by the method of hand shaking. The ultraviolet absorption spectrophotometric method was used for the determination of CBP. The method of dynamic dialysis was used for in vitro release of CBP from CBP-NS. The S-180 lung neoplasms models were established by i.v. cancer cells in mice. The number of pulmonary nodules was examined for evaluating the therapeutic efficacy.

RESULTS

The data showed that the mean diameter of CBP-NS was 3.72 microns, with a span of 0.66. The entrapment ratio of CBP in CBP-NS was 29.2% and the CBP-NS were stable for three months stored at 3 degrees C-5 degrees C, 15 degrees C-25 degrees C or 37 degrees C (relative humidity 75%). The release profile in vitro could be described by a biexpotential equation. The calculated values of the three targeting parameters indicated that CBP-NS showed good targeting efficiency. The results of therapeutic trials showed that the antitumor effects were significantly increased by injection of CBP-NS compared with CBP in the treatment of mice with lung carcinoma.

CONCLUSION

The results indicated that CBP-NS have good targeting efficiency in vivo, and the biodegradable CBP-NS may decrease the side effects of carboplatin and improve its therapeutic efficacy.

Effect of exercise and medium-chain fatty acids on postprandial lipemia

The purpose of this study was to evaluate the effect of medium-chain triglycerides (MCT) with and without exercise on postprandial lipemia (PPL). Subjects were 25 young men and women. Each subject performed three trials: 1) control (fat meal only, 1.5 g fat/kg) 2) MCT (substitution of MCT oil, 30% of fat calories), and 3) MCT + Ex (exercise 12 h before the MCT meal). Before each trial, the subject underwent consistent dietary preparation. Blood was collected on 2 separate days for baseline measurements of postheparin lipases and, in each trial, at 0 h (premeal), at 2, 4, 6, and 8 h after the fat meal for triglycerides and cholesterol ester transfer protein (CETP), and at 8 h for postheparin lipoprotein lipase (LPL) and hepatic lipase activities (HL). ANOVA indicated that the partial substitution of MCT oil to the fat meal did not affect the PPL response. However, the PPL was significantly lower after the MCT + Ex trial vs. the other trials. LPL activity was significantly elevated after all trials compared with baseline, whereas HL was lower in the MCT + Ex trial only. CETP mass was significantly lower at 4 and 8 h than 0 h during all trials but relatively higher in the MCT + Ex trial vs. the nonexercise trials. These results suggest that MCT does not affect the TG response to a fat meal. LPL and CETP are affected by a fat meal with or without exercise, but HL is affected only when exercise is included.

Siglec-9, a novel sialic acid binding member of the immunoglobulin superfamily expressed broadly on human blood leukocytes

Here we characterize the properties and expression pattern of Siglec-9 (sialic acid-binding Ig-like lectin-9), a new member of the Siglec subgroup of the immunoglobulin superfamily. A full-length cDNA encoding Siglec-9 was isolated from a dibutyryl cAMP-treated HL-60 cell cDNA library. Siglec-9 is predicted to contain three extracellular immunoglobulin-like domains that comprise an N-terminal V-set domain and two C2-set domains, a transmembrane region and a cytoplasmic tail containing two putative tyrosine-based signaling motifs. Overall, Siglec-9 is approximately 80% identical in amino acid sequence to Siglec-7, suggesting that the genes encoding these two proteins arose relatively recently by gene duplication. Binding assays showed that, similar to Siglec-7, Siglec-9 recognized sialic acid in either the alpha2,3- or alpha2, 6-glycosidic linkage to galactose. Using a specific mAb, Siglec-9 was found to be expressed at high or intermediate levels by monocytes, neutrophils, and a minor population of CD16(+), CD56(-) cells. Weaker expression was observed on approximately 50% of B cells and NK cells and minor subsets of CD8(+) T cells and CD4(+) T cells. These results show that despite their high degree of sequence similarity, Siglec-7 and Siglec-9 have distinct expression profiles.

Complete cDNA sequence and tissue localization of N-RAP, a novel nebulin-related protein of striated muscle

We have cloned and sequenced the full-length cDNA of N-RAP, a novel nebulin-related protein, from mouse skeletal muscle. The N-RAP message is specifically expressed in skeletal and cardiac muscle, but is not detected by Northern blot in non-muscle tissues. The full-length N-RAP cDNA contains an open reading frame of 3,525 base pairs which is predicted to encode a protein of 133 kDa. A 587 amino acid region near the C-terminus is 45% identical to the actin binding region of human nebulin, containing more than 2 complete 245 residue nebulin super repeats. The N-terminus contains the consensus sequence of a cysteine-rich LIM domain, which may function in mediating protein-protein interactions. These data suggest that the encoded protein may link actin filaments to some other proteins or structure. We expressed full-length N-RAP in Escherichia coli, as well as the nebulin-like super repeat region of N-RAP (N-RAP-SR) and the region between the LIM domain and N-RAP-SR (N-RAP-IB). An anti-N-RAP antibody raised against a 30 amino acid peptide corresponding to sequence from N-RAP-IB detected recombinant N-RAP and N-RAP-IB, but failed to detect N-RAP-SR. This antibody specifically identified a 185 kDa band as N-RAP on immunoblots of mouse skeletal and cardiac muscle proteins. In an assay of actin binding to electrophoresed and blotted proteins, we detected significant actin binding to expressed nebulin super repeats and N-RAP-SR, but only a trace amount of binding to N-RAP-IB. In immunofluorescence experiments, N-RAP was found to be localized at the myotendinous junction in mouse skeletal muscle and at the intercalated disc in cardiac muscle. Based on its domain organization, actin binding properties, and tissue localization, we propose that N-RAP plays a role in anchoring the terminal actin filaments in the myofibril to the membrane and may be important in transmitting tension from the myofibrils to the extracellular matrix.

Local angiotensin II and transforming growth factor-beta1 in renal fibrosis of rats

Studies have demonstrated that local angiotensin II (Ang II) generation is enhanced in repairing kidney and that ACE inhibition or AT(1) receptor blockade attenuates renal fibrosis. The localization of ACE and Ang II receptors and their relationship to collagen synthesis in the injured kidney, however, remain uncertain. Using a rat model of renal injury with subsequent fibrosis created with chronic elevations in circulating aldosterone (ALDO), we examined the distribution and binding density of ACE and Ang II receptors in repairing kidneys, as well as their anatomic relationship to transforming growth factor-beta1 (TGF-beta1) mRNA, type I collagen mRNA, collagen accumulation, and myofibroblasts. Two groups of animals (n=7 in each group) were studied: (1) normal rats served as controls, and (2) uninephrectomized rats received ALDO (0.75 microg/h SC) and 1% NaCl in drinking water for 6 weeks. Compared with control rats, in ALDO-treated rats we found (1) significantly (P<0.01) increased blood pressure, reduced plasma renin activity, and increased plasma creatinine levels, (2) diffuse fibrosis in both renal cortex and medulla, (3) abundant myofibroblasts at these sites of fibrosis, (4) significantly increased (P<0.01) binding density of ACE and Ang II receptors (60% AT(1), 40% AT(2)) at the sites of fibrosis, and (5) markedly increased (P<0.01) expression of TGF-beta1 and type I collagen mRNAs at these same sites. Thus, in this rat model of renal repair, the enhanced expression of ACE, Ang II receptors, and TGF-beta1 is associated with renal fibrosis. Ang II generated at the sites of repair appears to have autocrine/paracrine functions in the regulation of renal fibrous tissue formation alone or through its stimulation of TGF-beta1 synthesis.