Enhanced Cell Response to Zirconia Surface Immobilized with Type I Collagen

Zirconia (ZrO₂) dental implants provide good biocompatibility, have good corrosion resistance, and have a color that is similar to that of natural teeth. Unfortunately, ZrO₂ is a bioinert material and therefore achieves osseointegration difficultly. In this study, we sought to enhance osseointegration by producing rough ZrO₂ surfaces that contain hydroxyl groups (designated ZSA) through the use of sandblasting in conjunction with alkaline treatment. We immobilized type I collagen on ZSA surfaces using the natural cross-linker, procyanidin. Our results further showed that surfaces produced in ZSA-P/C featured more and steadier type I collagen than surfaces produced in ZSA-C. The ZSA-P/C also presented superior cell responses in terms of adhesion, proliferation, and mineralization of human bone marrow mesenchymal stem cells. The enhanced cell responses in the ZSA-P/C were induced through the prolonged activation of focal adhesion kinase, AKT (the phosphoinositide 3-kinase pathway), and p38 (the mitogen-activated protein kinase pathway). The simple and novel approach to immobilize type I collagen on roughened ZrO₂ surfaces presented in this article can likely benefit dental implant applications.

Potential therapeutic target for malignant paragangliomas: ATP synthase on the surface of paraganglioma cells

F1FoATP synthase (ATP synthase) is a ubiquitous enzyme complex in eukaryotes. In general it is localized to the mitochondrial inner membrane and serves as the last step in the mitochondrial oxidative phosphorylation of ADP to ATP, utilizing a proton gradient across the inner mitochondrial membrane built by the complexes of the electron transfer chain. However some cell types, including tumors, carry ATP synthase on the cell surface. It was suggested that cell surface ATP synthase helps tumor cells thriving on glycolysis to survive their high acid generation. Angiostatin, aurovertin, resveratrol, and antibodies against the α and β subunits of ATP synthase were shown to bind and selectively inhibit cell surface ATP synthase, promoting tumor cell death. Here we show that ATP synthase β (ATP5B) is present on the cell surface of mouse pheochromocytoma cells as well as tumor cells of human SDHB-derived paragangliomas (PGLs), while being virtually absent on chromaffin primary cells from bovine adrenal medulla by confocal microscopy. The cell surface location of ATP5B was verified in the tissue of an SDHB-derived PGL by immunoelectron microscopy. Treatment of mouse pheochromocytoma cells with resveratrol as well as ATP5B antibody led to statistically significant proliferation inhibition. Our data suggest that PGLs carry ATP synthase on their surface that promotes cell survival or proliferation. Thus, cell surface ATP synthase may present a novel therapeutic target in treating metastatic or inoperable PGLs.

Timing of gangrene tissue debridement after autologous bone marrow cell implantation in patients with superficial femoral arterial occlusion: preliminary experiences

AIM

Although implantation of bone marrow mononuclear cells (BMI) was shown to improve outcomes in patients with severe peripheral arterial occlusive disease (PAOD), little experience has been reported in patients with an arterial occlusion level above the knee, ischemic gangrene, and high cardiovascular risk. This study sought to investigate the timing of gangrene tissue debridement and the safety of BMI in these patients.

METHODS

Six "no-option" PAOD patients were enrolled with an arterial occlusion level above the knee, ischemic gangrene, and 3 systemic diseases related to a high cardiovascular risk. The ischemic status was evaluated by measuring the ankle-brachial index (ABI), transcutaneous oxygen pressure (TcPO2), and wound healing after BMI.

RESULTS

All patients safely underwent the procedures with intravenous general anesthesia by titrating propofol. Major lower extremity amputation, minor debridement amputation, and debridement surgery were performed in 2 (33.3%), 1 (16.7%), and 2 (33.3%) patients, respectively, 3.1 2.8 months after BMI. Compared to the amputation group (N=3), the salvage group (N=3) had a significantly higher baseline ABI (P=0.02) and a shorter distance between the gangrene site and arterial occlusion site (P=0.01). In the 3 patients who underwent debridement, ABI and TcPO2 significantly improved 1 month after BMI, and gangrenous tissues were debrided 3.8 ± 3.6 (range, 1~8) months after BMI with complete healing within 1 month.

CONCLUSION

Autologous BMI therapy is safe in patients at high cardiovascular risk with an arterial occlusion level above the knee and ischemic gangrene. Effective predictors of BMI include the baseline ABI and distance to the ischemia. Gangrene tissue should be debrided at least 1 month after BMI.

Meta-analysis of microarray-derived data from PACAP-deficient adrenal gland in vivo and PACAP-treated chromaffin cells identifies distinct classes of PACAP-regulated genes

Initial PACAP-regulated transcriptomes of PACAP-treated cultured chromaffin cells, and the adrenal gland of wild-type versus PACAP-deficient mice, have been assembled using microarray analysis. These were compared to previously acquired PACAP-regulated transcriptome sets from PC12 cells and mouse central nervous system, using the same microarray platform. The Ingenuity Pathways Knowledge Base was then employed to group regulated transcripts into common first and second messenger regulatory clusters. The purpose of our meta-analysis was to identify sets of genes regulated distinctly or in common by the neurotransmitter/neurotrophin PACAP in specific physiological contexts. Results suggest that PACAP participates in both the basal differentiated expression, and the induction upon physiological stimulation, of distinct sets of transcripts in neuronal and endocrine cells. PACAP in both developmental and acute regulatory paradigms acts on target genes also regulated by either TNFalpha or TGFbeta, two first messengers acting on transcription mainly through NFkappaB and Smads, respectively.

Synthesis and Characterization of Taper- and Rodlike Si Nanowires on SiXGe1-X Substrate

Taper- and rodlike Si nanowires (SiNWs) are synthesized successfully on Si and Si(0.8)Ge(0.2) substrates. The growth mechanisms of taper- and rodlike SiNWs are proposed to be oxide-assisted growth (OAG) and vapor-liquid-solid (VLS) growth, respectively. For taperlike SiNWs annealed at 1200 degrees C for 3 h, the emission peaks are found at 772, 478, and 413 nm. On the other hand, for rodlike SiNWs annealed at 1200 degrees C for 4 h, emission peaks are found at 783, 516, and 413 nm. From the field-emission measurements, the taperlike Si nanowires exhibit superior field-emission behavior with a turn-on field of 6.3-7.3 V/mum. The field enhancement, beta, has been estimated to be 700 and 1000 at low and high fields, respectively. The excellent field-emission characteristics are attributed to the perfect crystalline structure and the taperlike geometry of the Si nanowires.

Study of undifferentiated spondyloarthropathy among first-degree relatives of ankylosing spondylitis probands

OBJECTIVE

To estimate in a Chinese population the prevalence of undifferentiated spondyloarthropathy (USpA) among first-degree relatives (FDRs) of ankylosing spondylitis (AS) probands, and to compare the clinical features of familial USpA with those of sporadic USpA.

METHODS

The FDRs of two separate cohorts of consecutive AS probands were evaluated for the prevalence of USpA, using the Modified New York criteria and the European Spondylitis Study Group criteria for AS and SpA, respectively. Sporadic USpA and FDRs of non-SpA rheumatic patient probands served as separate controls.

RESULTS

Among the 301 FDRs of 102 AS probands, 7.0% were USpA. This was 1000 times higher than the 147 FDRs of 40 non-SpA probands (P = 0.00230). Within the AS families, USpA was less male-dominated than AS (33.3 vs 72.5%) (P = 0.006). The only feature distinguishing familial from sporadic USpA was that the percentages of HLA B27 were 100 and 50%, respectively (P<0.001).

CONCLUSION

USpA and AS coexist in the same Chinese families, both being predisposed by HLA B27. In these families, a female gender favours the development of USpA rather than AS. A significant subset of sporadic USpA (HLA B27-negative group) has a different genetic predisposition compared with familial USpA.

Role of protein kinases in neuropeptide gene regulation by PACAP in chromaffin cells: a pharmacological and bioinformatic analysis

Pituitary adenylate cyclase-activating polypeptide (PACAP) is an adrenomedullary cotransmitter that along with acetylcholine is responsible for driving catecholamine and neuropeptide biosynthesis and secretion from chromaffin cells in response to stimulation of the splanchnic nerve. Two neuropeptides whose biosynthesis is regulated by PACAP include enkephalin and vasoactive intestinal polypeptide (VIP). Occupancy of PAC1 PACAP receptors on chromaffin cells can result in elevation of cyclic AMP, inositol phosphates, and intracellular calcium. The proenkephalin A and VIP genes are transcriptionally responsive to signals generated within all three pathways, and potentially by combinatorial activation of these pathways as well. The characteristics of PACAP regulation of enkephalin and VIP biosynthesis were examined pharmacologically for evidence of involvement of several serine/threonine protein kinases activated by cAMP, IP3, and/or calcium, including calmodulin kinase II, protein kinase A, and protein kinase C. Evidence is presented for the differential involvement of these protein kinases in regulation of enkephalin and VIP biosynthesis in chromaffin cells, and for a prominent role of the mixed-function (tyrosine and serine/threonine) MAP kinase family in mediating transcriptional activation of neuropeptide genes by PACAP.

Adaptive phase field simulation of dendritic growth in a forced flow at various supercoolings

An efficient finite volume method is developed for the phase-field simulation of two-dimensional dendritic growth in a forced flow at various supercoolings. The adaptive nature of the method allows the dendrite in a large domain to evolve secondary structures, even at low supercoolings. In addition to good agreement with previous calculations on the tip shape and speed, the effects of forced flow at various supercoolings are investigated and compared with the Oseen-Ivantsov solution and good agreement is found. The steady dendrite shape in all cases continues to have a self-affine nature and the invariant scaling parameters are in good agreement with the estimation.

Inhibition of inducible nitric oxide synthase (iNOS) prevents lung neutrophil deposition and damage in burned rats

This study was designed to investigate the role of NO and effect of iNOS inhibitor on the lung neutrophil deposition and damage after burn. In Experiment 1, specific pathogen-free (SPF) Sprague-Dawley rats underwent 35% total body surface area (TBSA) burn. On the 4th, 8th, 16th, and 24th h after burn, blood was collected for peroxynitrite-mediated dihydrorhodamine 123 (DHR 123) oxidation assay, and lung tissues were harvested for myeloperoxidase (MPO) test and histologic study. Pulmonary microvascular dysfunction was quantitated by measuring the extravasation of Evans blue dye (EBD). In Experiment 2, S-methylisothiourea (SMT) was given (7.5 mg/kg, intraperitoneal immediately post-burn) to suppress iNOS activity. On the 8th h after burn, the effect of SMT on blood DHR 123 oxidation, lung MPO, lung damage, and lung iNOS expression were evaluated. Lung MPO activity increased up to a maximum of 2-fold 8 h after burn. Blood DHR 123 oxidation increased up to a maximum of 2-fold 8 h after burn. Lung permeability increased up to a maximum of 2.5-fold 4 h after burn. SMT significantly decreased lung MPO activity, blood DHR 123 oxidation, and lung permeability by 31%, 41%, and 54%, respectively. SMT markedly decreased the thermal injury-induced perivascular and interstitial inflammatory cell infiltration and iNOS staining in bronchiolar epithelium, endothelial cells, and perivascular and interstitial inflammatory cells. In conclusion, thermal injury induces blood DHR 123 oxidation, lung neutrophil deposition, lung iNOS expression, and lung damage. Peroxynitrite might play an important role in thermal injury-induced lung neutrophil deposition and damage. Specific inhibition of lung iNOS expression and blood DHR 123 oxidation with SMT on thermal injury not only attenuated the lung neutrophil deposition, but also reduced lung damage.

Effects of bombesin on gut mucosal immunity in rats after thermal injury

BACKGROUND AND PURPOSE

Severe burns induce a disruption in gastrointestinal mucosal integrity and facilitate bacterial translocation (BT). Bombesin (BBS), a tetradecapeptide analogous to mammalian gastrin-releasing peptide, can induce the release of all gut hormones except secretin. This study examined the effects of BBS on mucosal immunity in rats after thermal injury.

METHODS

Forty-two Sprague-Dawley rats were divided into one sham control group and six burn groups. Burn groups were subjected to 35% total body surface area burn injury. One to 6 days after the injury, six animals (one from each group) were killed every 24 hours. Biliary secretory immunoglobulin A (SIgA), jejunal mucosal height, intestinal permeability, and BT to the mesenteric lymph nodes (MLNs), liver, and spleen were examined. In a second experiment, three groups of rats (6 in each) received either sham treatment and saline injection, or thermal injury and saline injection, or thermal injury and BBS injection. Twenty-four hours after burns or sham treatment, six animals (1 from each group) were killed. The biliary SIgA, jejunal mucosal height, and BT to the MLNs, liver, and spleen were examined.

RESULTS

The biliary SIgA decreased to one-seventh of normal levels 1 day after burn injury, and increased thereafter. The jejunal mucosal height decreased significantly to two-thirds of the normal value 1 day after burn injury. The intestinal mucosal permeability increased significantly to three times the normal level 2 days after the burn injury, and decreased thereafter. BBA significantly reduced the BT incidence and significantly increased the biliary SIgA and jejunal mucosal height 1 day after burn injury.

CONCLUSIONS

The results of this study show that, in rats, the intestinal permeability increased, the gut mucosal barrier failed, and the gut immunity deteriorated in the first few days after burn injury. BBS therapy helped to restore the postburn gut mucosal barrier in rats, by increasing biliary SIgA levels and the jejunal mucosal height.

Identification of victims of the 1998 Taoyuan Airbus crash accident using DNA analysis

In February 1998 a civilian aeroplane carrying 196 individuals crashed in Taiwan and killed another 6 people on the ground. Although there were dental and medical records, fingerprints, photographic evidence and personal effects to identify some of the victims, DNA analysis was required to further identify severely damaged remains. From the 202 people known to have perished in the plane crash, a total of 685 fragments of human remains were subjected to DNA analysis. The analysis was carried out using nine microsatellite loci, plus amelogenin to cluster the 685 fragments into 202 groups, accounting for all the victims. To establish genetic relatedness of the victims to other victims and living relatives, additional DNA loci were used. In this case the paternity index was increased by using HLA DQA1 plus Polymarker. The same 16 DNA loci were used to test blood samples from 201 relatives to establish parent/child and sibling relationships. With the exception of 19 victims identified by non-genetic evidence, 183 victims were successfully identified by DNA typing with relatively high values of paternity index by the direct or indirect comparison of relatives. The 202 victims were from 37 different families, ranging in size from 2 to 13 members and 74 individuals known to be unrelated to any other victim. The DNA from living relatives was used to identify one member of a family group, from which other victims of the family could be identified. ABO blood group information was further used to confirm genetic relatedness within families. A comparison of the DNA profiling results to the ABO blood group of the victims showed no discrepancies with the exception of two mutations in the FGA locus. In cases of severely damaged victims from a plane crash, DNA analysis proved to be the best choice to identify victims.

Nitric oxide synthase inhibitor ameliorates oral total parenteral nutrition-induced barrier dysfunction

The expression of inducible nitric oxide synthase (iNOS) is increased in the intestine and results in mucosal damage after endotoxin challenge. Although the oral administration of total parenteral nutrition (TPN) solution promotes bacterial translocation (BT) and increases the intestinal permeability, the role of NO in the nutrition-induced loss of mucosal barrier function remains unclear. The distribution of fluorescein isothiocyanate-dextran (FITC-dextran, 4400) across the lumen of small intestine in rat was examined to investigate the role of NOS activity on the intestinal permeability under oral TPN feeding. Fifty-one rats were randomly divided into 4 groups. Group I (control group) was fed with rat chow, group II received TPN solution orally. Groups III and IV received TPN solution supplemented with NOS inhibitors. On day 9, FITC-dextran was injected into the intestinal lumen. After 30 min, blood samples were taken from portal vein and analyzed for plasma FITC-dextran level by fluorescence spectrophotometry. Samples of small intestine were frozen and sectioned in a cryostat for morphological and NOS histochemical studies. Homogenates of small intestine were used for NOS activity measurement. The plasma level of FITC-dextran showed a significant increase (P < 0.05) in rats fed with oral TPN compared with the control ones. Supplement with NOS inhibitors significantly decreased the intestinal permeability in groups III and IV compared with group II. Similarly, the total NOS activities showed a significant 2-fold increase (P< 0.05) in group II, and NOS inhibitors decreased the elevated NOS activity. These data suggest that oral TPN feeding for 9 days leads to an increase in permeability to dextran and the total NOS activity of small intestine, and both induction of the intestinal permeability and NOS activity were inhibited by treatment with NOS inhibitors. Addition of S-methylisothiourea (SMT), an iNOS selective inhibitor, profoundly inhibited 66% of the induced iNOS activity (P < 0.05) and reduced 74% of the diet-induced increase in intestinal permeability (P < 0.05) in group II. The induced permeability change in rats receiving oral TPN is mainly due to the activity of intestinal mucosal iNOS. The induction of iNOS is an important mediator for intestinal barrier dysfunction. Administration of SMT, which specifically decreases iNOS activity, is useful in the prevention of diet-induced barrier failure.

Pituitary adenylate cyclase-activating polypeptide regulation of vasoactive intestinal polypeptide transcription requires Ca2+ influx and activation of the serine/threonine phosphatase calcineurin

A >15-fold increase in vasoactive intestinal polypeptide (VIP) mRNA and VIP peptide levels occurred in primary chromaffin cells following exposure to the neurotrophic neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP)-27 with an EC50 of approximately 2 nM. PACAP induction of VIP expression was blocked by methoxyverapamil or by a combination of nimodipine and omega-conotoxin MVIIC, indicating a requirement for PACAP-initiated calcium entry through voltage-dependent calcium channels for regulation of VIP biosynthesis. Ascomycin, which inhibits calcineurin through formation of an ascomycin/FKBP12/calcineurin ternary complex, abolished the PACAP-evoked increase in VIP expression, whereas rapamycin, which also binds to FKBP12 but does not cause inhibition of calcineurin, did not. Cyclosporin A, which inhibits calcineurin through formation of a cyclosporin A/cyclophilin/calcineurin complex, also abolished PACAP-evoked VIP biosynthesis. These data indicate that PACAP regulates the expression of VIP via a signaling pathway that requires calcium influx and activation of calcineurin.

Changes in gut mucosal nitric oxide synthase (NOS) activity after thermal injury and its relation with barrier failure

This study was designed to investigate changes in mucosal NOS activity after burns and its relation to barrier failure. In Experiment 1, female specific pathogen free (SPF) Sprague-Dawley rats underwent 35% total body surface area (TBSA) burn. One to six days after burn, intestinal permeability was determined from the plasma leakage of fluorescein isothiocyanate (FITC)-dextran 4400, intestinal mucosal cNOS and iNOS activity were assayed using Griess' reagent, and the cellular localization of iNOS was examined using immunostaining. In Experiment 2, S-methylisothiourea (SMT) was given (5 mg/kg, i.p. every 12 h) for 2 days to suppress inducible NOS (iNOS) activity after thermal injury. On postburn Day 2, the effect of SMT on gut mucosal NOS activity, intestinal permeability, and barrier function were evaluated. The activity of iNOS increased 24 h after the injury and up to a maximum of twofold on postburn Day 2, and decreased thereafter. The increase in iNOS activity in gut mucosa correlated well with the increase in intestinal permeability, an index for barrier failure (r = .776, p = .0002). Results from iNOS immunostaining showed that changes in mucosal iNOS activity after the burn occurred mainly in the enterocytes rather than in the macrophages. Administration of SMT decreased mucosal iNOS activity, intestinal permeability, and bacterial translocation incidence to mesenteric lymph node concurrently. In conclusion, thermal injury induces intestinal mucosal iNOS, which is principally in the enterocytes. The increased intestinal iNOS activity was closely related to barrier failure. SMT inhibited intestinal mucosal iNOS activity and prevented barrier failure as demonstrated by a decrease in BT occurrence and intestinal permeability.

Specific inhibition of iNOS decreases the intestinal mucosal peroxynitrite level and improves the barrier function after thermal injury

Failure of GI tract mucosa to act as a barrier against bacterial translocation (BT) has been proposed as a potential source of sepsis and subsequent multiple organ failure post thermal injury. Nitric oxide (NO) is an inorganic radical produced by NO synthase (NOS) from L-arginine. Gut mucosal constitutive NOS (cNOS) provides protection for itself. In contrast to cNOS, inducible NOS (iNOS) releases far greater amounts of NO, promotes oxidative reactions and is responsible for tissue injury. Peroxynitrite formed by the rapid reaction between superoxide and NO, is a toxic substance that contributes to tissue injury in a number of biological systems. This study was designed to investigate the effect of iNOS specific inhibitor S-methylisothiourea (SMT) on the postburn intestinal mucosal barrier function and the possible mechanism of SMT's action. Female SPF Sprague Dawley rats underwent 35% total body surface area (TBSA) or sham burn. Either SMT or the same volume of saline was given (5 mg/kg, i.p. q 12 h) for 2 days to assess the effect of iNOS inhibition. On postburn day 2, the intestinal mucosal cNOS and iNOS activity were assayed by using Griess' reagent, the mesenteric lymph node (MLN), spleen and liver were collected and cultured for BT assay and the cellular localization of nitrotyrosine, a marker for peroxynitrite activity, was examined by immunostaining. After thermal injury in rats, administration of SMT for 2 days decreased the intestinal mucosal iNOS activity/ tNOS activity ratio and the BT incidence. Nitrotyrosine immunostaining of the intestinal mucosa showed a decrease in the SMT-treated group. These findings suggest that SMT, a specific inhibitor for iNOS improves the barrier function after burn by suppression of the intestinal mucosal iNOS activity. The decrease in NO production resulted in decreased formation of peroxynitrite and subsequently decreased damage of mucosal tissue.

PACAP activates calcium influx-dependent and -independent pathways to couple met-enkephalin secretion and biosynthesis in chromaffin cells

Pituitary adenylate cyclase activating polypeptide-27 (PACAP-27) caused a dose-dependent increase in met-enkephalin secretion and increased production of met-enkephalin peptide and proenkephalin A (PEnk) mRNA in bovine chromaffin cells, at concentrations as low as 300 pM. PACAP-38 was less potent than PACAP-27, but had similar effects. Vasoactive intestinal polypeptide (VIP) (1-100 nM) was without appreciable effect on either enkephalin secretion or biosynthesis, implicating PACAP type I receptors in PACAP-stimulated enkephalin secretion and synthesis. PACAP type I receptors can activate adenylate cyclase and stimulate phospholipase C through heterotrimeric G protein interactions, leading to increased intracellular cyclic AMP (cAMP), inositol triphosphate (IP3)-mediated calcium mobilization, and calcium- and diacylglycerol (DAG)-mediated protein kinase C (PKC) activation. Enkephalin secretion evoked by 10-100 nM PACAP-27 was not inhibited by 1 microM (-)-202-791, an L-type specific dihydropyridine calcium channel blocker, but was inhibited 65-80% by the arylalkylamine calcium channel blocker D600. Forty mM potassium-evoked secretion was inhibited > 90% by both D600 and (-)-202-791, 25 microM forskolin-induced secretion was blocked < 50% by D600 and was unaffected by (-)-202-791, and 100 nM phorbol myristate acetate (PMA)-induced secretion was unaffected by either D600 or (-)-202-791. Enkephalin biosynthesis was increased by 10 nM PACAP-27, as measured by increased met-enkephalin pentapeptide content and PEnk A mRNA levels. PACAP-, forskolin-, and PMA-stimulated enkephalin synthesis were not blocked by D600 or (-)-202-791. Elevated potassium-induced enkephalin biosynthesis upregulation was completely blocked by either D600 or (-)-202-791 at the same concentrations. PACAP acting through type I PACAP receptors couples calcium influx-dependent enkephalin secretion and calcium influx-independent enkephalin biosynthesis in chromaffin cells. Restriction of the effects of enhanced calcium influx to stimulation of secretion, but not of biosynthesis, is unique to PACAP. By contrast, potassium-induced enkephalin biosynthesis upregulation is completely calcium influx dependent, specifically via calcium influx through L-type calcium channels. We propose that subpopulations of voltage-dependent calcium channels are differentially linked to intracellular signal transduction pathways that control neuropeptide gene expression and secretion in chromaffin cells.

Seroepidemiological study of measles after the 1992 nationwide MMR revaccination program in Taiwan

The incidence of measles declined rapidly in Taiwan after the introduction of the measles vaccine into the routine immunization schedule in 1978. However, an epidemic still occurred every 3-5 years until recently. A nationwide measles-mumps-rubella (MMR) revaccination program for school and preschool children has been in place since 1992 to control the indigenous transmission of measles. In order to understand the current immune status after this recent nationwide revaccination program, we determined the presence of measles IgG antibodies by enzyme-linked immunosorbent assay (ELISA) in 1,281 blood samples from healthy persons aged from 2 months to above 30 years collected between 1993 and 1995, and also in another batch of 90 sera samples from children aged 2 years collected before 1992. The results showed that 1) the measles antibody seropositive rate (36.4%) was lowest in children aged 5-7 months and rose to an unexpectedly high level of 85.8% at the age of 12-14 months, 2) the seropositive rate rose further to between 85.9% and 95.1% after 2 years of age and remained high in adults and pregnant women, and 3) the seropositive rate of the 2-year-old children collected before 1992 was 61.4%, which was significantly lower than the rate of the same age group collected after the nationwide MMR revaccination program. We conclude that the national revaccination program has promoted effectively measles immunity in Taiwan. This immunity explains the rarity of reported measles cases since the last epidemic in 1989. This revaccination program should continue and be extended to all preschool children and young adults so that indigenous measles can be eliminated by the year 2000.

Prevalence of Legionella pneumophila infection in children and its role in pediatric community-acquired atypical pneumonia

The infection status of Legionella pneumophila in children and its role in pediatric community-acquired pneumonia were investigated. Because exposure to Legionella pneumophila may be highly variable and there has been no unanimously agreed-upon cut-off values in previous seroprevalence studies, 60 serum samples collected from infants aged 12 to 18 months were examined using immunofluorescence antibody test to determine the cut-off titer which represents past Legionella pneumophila infection. An IFA titer of greater than or equal to 32 was found to be suitable to represent past L. pneumophila infection. A seroepidemiological study of the prevalence of L. pneumophila in 180 children showed the prevalences in children aged 7 to 18 years to be between 28.4 and 35%. Fifty-three paired sera were tested to determine the role of Legionella pneumophila in pediatric, community-acquired, atypical pneumonia. The frequency of confirmed disease was 0% and of presumptive cases was 5.7%. Legionella pneumophila was not a common etiologic agent of pediatric pneumonia in Taiwan.

Efficacy of ultrafiltration in removing inflammatory mediators during pediatric cardiac operations

BACKGROUND

Conventional and modified ultrafiltration was used in pediatric cardiac operations to reduce volume overload and total body water. The purpose of this study was to compare the efficacy of these techniques in removing inflammatory mediators during cardiopulmonary bypass.

METHODS

Fifty pediatric patients undergoing cardiac operations were randomized into a modified or conventional ultrafiltration group. Blood samples were obtained before and after ultrafiltration to assess the plasma concentrations of leukocyte elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8.

RESULTS

Except for plasma concentrations of tumor necrosis factor-alpha in the modified ultrafiltration group, the plasma concentrations of all the mediators measured increased after ultrafiltration in both groups of patients. The volume of ultrafiltrate and the total amounts of tumor necrosis factor-alpha and interleukin-6 removed by ultrafiltration were significantly greater in the modified group. The concentrations of mediators in the ultrafiltrate and the ratio of ultrafiltrate to plasma concentrations of the mediators did not differ between the groups. Ultrafiltration was more efficient in removing tumor necrosis factor-alpha than the other mediators.

CONCLUSIONS

The efficacy in removing the inflammatory mediators generated during cardiopulmonary bypass did not differ between modified and conventional ultrafiltration.

A seroepidemiological study of Varicella-Zoster virus in Taipei City

Varicella has been considered a common and benign disease of children. However, adults tend to have severe disease and in some high risk groups, such as neonates and leukemic patients, varicella infection can be fatal. A large-scale seroepidemiological study on varicella was performed to reveal the current varicella infection status and to serve as a prevaccination survey before the possible implementation of vaccination program in Taiwan. This study included a total of 1384 individuals whose ages ranged from newborns to old adults. Enzyme-linked immunosorbent assay was adopted to determine the IgG antibodies against Varicella-Zoster virus. The results showed: (1) only 24% of infants aged birth to three months had maternal antibodies, (2) the seroprevalence increased slowly during the first 3 years after birth, (3) most infections occurred between 3 and 10 years old, (4) 10% (female) to 20% (male) of adults were still susceptible to varicella infection, and (5) 85% of pregnant women had antibodies against VZV. These data suggest that if varicella vaccination is to be done in Taiwan, the appropriate inoculation age would be between 12 and 24 months. Besides, there exists a pool of uninfected adults who potentially will develop severe illnesses once infected and should be screened and protected by varicella vaccines.

Lupus in Chinese male: a retrospective study of 61 patients

BACKGROUND

Systemic lupus erythematosus (SLE) has traditionally been considered a disease of women, and is uncommon in men. In recent years, several large clinical series of male lupus patients have been reported. As no known data are available for lupus in males from Taiwan, a retrospective analysis of data from male lupus patients was done to determine whether these patients differed from other series of male or female SLE patients in the literature.

METHODS

Sixty-one male lupus patients, diagnosed and followed in Tri-Service General Hospital, between 1983 and 1993, were studied and their data analyzed, retrospectively.

RESULTS

The mean age of diagnosis was 30 +/- 17 (mean +/- SD, range: 13-81) years. The peak age of diagnosis was between 13 and 40 years. The mean duration of follow-up was 36 +/- 36 (range: 2-256) months. The 1-, 5- and 10-year survival rates were 84%, 76% and 75%, respectively. The frequency of clinical manifestations were renal disease, 75%; malar rash, 70%; arthritis, 60%; fever, 56%; photosensitivity, 48%; pleuritis, 39%; pericarditis, 31%; alopecia, 31%; mucosal ulcers, 29%; neuropsychiatric disease, 26%; discoid lupus, 21%; vasculitis, 15%; Raynaud's phenomenon, 10%; and lymphadenopathy, 2%. The frequency of abnormal laboratory findings were antinuclear antibodies (ANA), 95%; hypocomplementemia, 77%; antibodies to double-stranded DNA (anti-dsDNA), 57%; leukopenia, 44%; lupus erythematosus (LE) cells, 39%; anti-Ro, 39%; anti-Smith antibodies (anti-Sm), 19%; thrombocytopenia, 18%; rheumatoid factor, 17%; anti-ribonucleoprotein antibody (anti-RNP), 14%; autoimmune hemolytic anemia, 8%; false-positive venereal disease research laboratory test (VDRL), 6% and anti-La, 4%.

CONCLUSIONS

In a review of the 61 ethnic Chinese male lupus patients, a higher frequency of renal disease, malar rash and photosensitivity, but a lower frequency of arthritis and lymphadenopathy, compared to previous reports of Caucasians. There were no significant immunological differences from other series of male lupus, except a lower frequency of anti-dsDNA. In general, poor prognosis was noted for male lupus patients here.

Outbreak of aseptic meningitis in Taipei in spring 1993

An outbreak of aseptic meningitis in the Taipei area occurred from January to August 1993. A total of 114 cases were identified by cerebrospinal fluid (CSF) examination at National Taiwan University Hospital. Most of the cases were found from February to May 1993. The peak of age distribution was 3 to 11 years. The male-to-female ratio was 2.1 to 1. Most patients had fever, headache, and vomiting and nausea. On initial CSF examination, protein concentrations > 400 mg/L were noted in 38 of 93 CSF samples, while 19 of 70 initial samples had hypoglycorrhachia (CSF/serum glucose ratio < 0.5). CSF white cell counts of the initial lumbar puncture were 0-9 x 10(6) cells/L in 4 patients, 10-99 x 10(6) cells/L in 42 patients, 100-199 x 10(6) cells/L in 27 patients, 200-499 x 10(6) cells/L in 24 patients, 500-999 x 10(6) cells/L in 12 patients and > or = 1,000 x 10(6) cells/L in 5 patients. Polymorphonuclear cells predominated in 73 of 114 cases. Viral cultures from CSF, throat swabs and rectal swabs were done with a majority yielding enteroviruses. Enterovirus as a definite etiology was found in 58 of 114 cases and was the presumptive etiology in 15 of 114 cases. The serotypes of the enteroviruses isolated were mostly echovirus type 30. All patients recovered without obvious sequelae.

Coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis associated with ankylosing spondylitis: a case report

A patient with ankylosing spondylitis and coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis is described. Renal biopsy demonstrated mesangial proliferative glomerulonephritis with prominent IgA, C3 and fibrin deposition in the glomeruli. Simultaneously, leukocytoclastic cutaneous vasculitis with prominent IgG, IgA and C3 deposition of dermal vessel wall was also observed in the skin biopsy specimen. Such associations have been previously reported in only four cases. This report once again indicates that antigenic mucosal stimulation may play an important role in the pathogenesis of ankylosing spondylitis.

An experimental model of osteoarthritis in rabbit

BACKGROUND

From both a microscopic and a metabolic view, experimental animal models are very important for study of the pathogenesis of osteoarthritis. A new, different operative procedure was used in rabbit models, and the pathologic findings were evaluated.

METHODS

Twelve New Zealand white rabbits were divided into six groups; eight were used as animal models and four, for drug efficacy study. Transection of the anterior cruciate and medial collateral ligaments on the left knee joint, and sham-operation were performed on the right knee joint. Rabbits were sacrificed post surgery from 4, 6, 8 and 12 weeks. Eight parameters from gross to microscopic findings were used in order to evaluate osteoarthritic changes. Indomethacin and aspirin were chosen for the drug efficacy experiment; the two rabbits of each group were sacrificed at the end of the sixth week post-surgery.

RESULTS

According to pathological findings, this operative procedure can produce osteoarthritic changes, visible both microscopically and macroscopically. There were osteoarthritic changes in the fourth week post-surgery group and, obviously, in the eighth week; these persisted until 12th weeks post-surgery. Neither indomethacin nor aspirin showed any effect in preventing osteoarthritis progression.

CONCLUSIONS

Transection of the anterior cruciate and medial collateral ligament rabbit model can produce osteoarthritic lesions in the knee joint. This model can be used for further biochemical and metabolic studies.

Positive antinuclear antibody in peripheral T cell lymphoma: a case report

The association of malignant lymphoma with positive antinuclear antibody is uncommon, and their relationship is not clear. Here a 35-year-old man is presented who initially had a high titer of antinuclear antibody; later, peripheral T cell lymphoma was found. It is suggested than an unexplained high antinuclear antibody titer may warrant searching for a malignancy.

Intermittent intravenous treatment of lupus nephritis with cyclophosphamide: a four-year experience with twenty-four patients

BACKGROUND

Renal involvement in systemic lupus erythematosus commonly leads to renal failure and death. We conducted a study to evaluate the efficacy and side effects of intermittent intravenous treatment with cyclophosphamide of patients with lupus nephritis.

METHODS

Twenty-four patients with lupus nephritis were recruited at Tri-Service General Hospital from 1988 to 1992. Cyclophosphamide was administered intravenously monthly for three months, and then every three months. 24-hour urinary protein, creatinine clearance, serum creatinine, blood urea nitrogen, C3 and C4 levels, serum albumin, hemoglobin, and dosage of prednisolone were recorded before each treatment. During treatment, the side effects were monitored.

RESULTS

Two patients progressed to renal failure within one year and one patient after three years. Fifteen patients completed therapy for one year. Among these 15 patients, the levels of hemoglobin, serum albumin, and C3 significantly increased at six months, then became stable; the level of C4 increased at 12 months. In contrast, the dosage of prednisolone decreased significantly at six months. There was no significant difference of creatinine clearance, 24-hour urinary protein, serum creatinine, and blood urea nitrogen before and after treatment. The most common side effects were nausea and vomiting. No severe side effect necessitated discontinuing therapy with cyclophosphamide.

CONCLUSIONS

Intermittent intravenous therapy in lupus nephritis with cyclophosphamide can significantly increase levels of hemoglobin, serum albumin, C3 and C4, and keep renal function stable. Poor response was found in a subset of patients. The side effects were mild in the present study.

Enkephalin biosynthesis is coupled to secretory activity via transcription of the proenkephalin A gene

The molecular mechanisms regulating neuropeptide and secretory protein biosynthesis in neuroendocrine cells were examined using the prototype neuropeptide and secretory proteins enkephalin and chromogranin A (CGA). Treatment with the secretogogue nicotine results in the calcium-dependent secretion of enkephalin peptides from bovine chromaffin cells in primary culture and a concomitant increase in enkephalin peptide biosynthesis. Both secretion and biosynthesis are also stimulated by cell depolarization with elevated potassium. Elevation of intracellular cyclic AMP, on the other hand, results in stimulation of enkephalin biosynthesis and long-term, but not acute, secretion of enkephalin peptides. Coupling of enkephalin biosynthesis to calcium influx occurs at the level of transcription of the enkephalin gene. Thus, potassium depolarization causes a calcium-dependent elevation of enkephalin mRNA which is preceded by an increase in the rate of transcription of the enkephalin gene in the chromaffin cell. The accumulation of enkephalin message or peptide by potassium depolarization or treatment with nicotine is prevented by D600 or hexamethonium respectively, added 1 h after addition of nicotine or KCl and following acute release, suggesting that calcium acts as a continuous rather than triggering stimulus for enkephalin biosynthesis. Sequence analysis of the bovine enkephalin promoter identified sequence conservation of three enhancers previously reported in the human gene which are required for regulation of the gene by calcium, cAMP, and phorbol ester in vitro. In contrast to the regulation of the enkephalin system, no increase in either CGA or CGB mRNA or gene transcription attended depolarization-induced secretion from chromaffin cells. Since enkephalin and CGA are co-stored in and co-released from the same secretory vesicles in these cells, the results imply that a surplus of CGA is constitutively synthesized in chromaffin cells such that compensatory up-regulation during changes in the secretory state of the cell, such as occurs for enkephalin, is not required for the secretory proteins.

Flow cytometric DNA and cytomorphometric analysis in renal cell carcinoma: its correlation with histopathology and prognosis

Cell material from 49 cases of archival paraffin-embedded tumor specimens of newly diagnosed renal cell carcinoma (RCC) was studied retrospectively using rapid flow cytofluorometric (propidium iodide) DNA analysis. The degree of ploidy (DNA index), percentage of cells in the S-phase (SPF), and modal nuclear size were determined from histograms. The tumors were classified as diploid (DNA index = 0.9-1.1) or aneuploid. Proliferative activities of the tumors were assessed from the proportion of S-phase cells. The aneuploid occurrence was 77.6% in our series. Univariate and multivariate logistic regression analyses of DNA ploidy and associated parameters showed that DNA ploidy was correlated with SPF of cells (P = 0.0061) as no correlation was seen between DNA ploidy, sex, age, histological type, tumor size, stage, and nuclear size (P = 0.0697). Multiple aneuploid stem lines had no influences on ploidy and prognosis. Comparison of survival data using the multivariate stepwise hazard rate and Lee-Desu statistics showed that patient prognosis was closely related to tumor size (P = 0.006) and staging (P < 0.0001). DNA ploidy had marginal correlation to progression and disease-specific death (P = 0.064). Nevertheless, flow cytometric analysis in conjunction with conventional histopathology may have a potential role for the management of patients with RCC.

A point mutation in the chloroplast rps12 gene from Nicotiana plumbaginifolia confers streptomycin resistance

In an effort to understand the mechanism of streptomycin resistance in Nicotiana plumbaginifolia, we have sequenced the chloroplast rps12 gene, a potential molecular target. We report that a streptomycin-resistant mutant isolated from protoplast cultures of N. plumbaginifolia contains an A-to-G transition at nucleotide position 149 in exon 2 of the chloroplast rps12 gene. The detected point mutation predicts a substitution of arginine for lysine in a phylogenetically conserved region.

Cytomorphometric and flow cytometric analysis of bladder transitional cell carcinoma using acridine orange fluorochrome: correlation with histopathology and clinical behavior

Cell material from 79 cases of archival paraffin-embedded tumor specimens of newly diagnosed transitional cell carcinomas of the urinary bladder was studied retrospectively using rapid flow cytofluorometric DNA analysis. The male to female ratio was 62/17. The mean age at diagnosis was 65.3 +/- 10.8 years. Clinical characteristics, including survival, recurrence and progression were closely related to the histopathologic grading and tumor staging. The tumors were classified as diploid (DI = 0.9-1.1) or aneuploid. Total aneuploid occurrence was 46%. The aneuploid frequency for the various tumor grades was 25% for grade 1, 37% for grade 2 and 78% for grade 3. Stages Ta (O) and Tl (A) tumors differed from muscle-invasive tumors (T2-4) in that they had a lower frequency of aneuploid occurrence (34%, 41% vs 50%, 73%, and 75%). Multiple aneuploid stem cell lines had no influence on tumor grade or stage. The DNA ploidy was closely related to the five-year survival rate, the probability of tumor recurrence and progression. On the contrary, the modal nuclear size of the tumor cells had no correlation with histopathology or the clinical characteristics. Bladder tumors of an intermediate grade (grade 2) may be subdivided into two groups with different outcomes on the basis of flow cytometric characteristics. It is concluded that DNA flow cytometry can serve as an additional prognostic parameter for bladder cancer patients in addition to conventional histopathology.

A plasmid-encoded anion-translocating ATPase

An anion-translocating ATPase has been identified as the product of the arsenical resistance operon of resistance plasmid R773. When expressed in Escherichia coli this ATP-driven oxyanion pump catalyzes extrusion of the oxyanions arsenite, antimonite and arsenate. Maintenance of a low intracellular concentration of oxyanion produces resistance to the toxic agents. The pump is composed of two polypeptides, the products of the arsA and arsB genes. This two-subunit enzyme produces resistance to arsenite and antimonite. A third gene, arsC, expands the substrate specificity to allow for arsenate pumping and resistance.

Sequence analysis, tissue distribution and regulation by cell depolarization, and second messengers of bovine secretogranin II (chromogranin C) mRNA

Secretogranin II is a very acidic, tyrosine-sulfated protein found in secretory granules of cells belonging to the diffuse neuroendocrine system. It gained more general importance recently as a universal immunohistochemical marker for endocrine neoplasms. Sequence information was obtained from secretogranin II isolated from bovine anterior pituitaries, allowing the isolation of cDNA clones and deduction of its primary structure. Bovine secretogranin II is a 586-amino acid protein of 67,455 Da which is preceded by a signal peptide of 27 residues and contains 9 pairs of basic amino acids in its sequence which are used as potential cleavage sites for generation of physiologically active peptides. Moderately abundant mRNA levels were found in adrenal medulla, pituitary, hippocampus, and caudate. Secretogranin II message was absent from parathyroid gland, adrenal cortex, kidney, liver, and spleen. Depolarization of isolated chromaffin cells by various secretagogues significantly up-regulated secretogranin II mRNA levels by mechanisms distinct from those established for chromogranins and neuropeptides, components maintained along with secretogranin II in neuroendocrine storage vesicles.

Molecular analysis of an ATP-dependent anion pump

The plasmid-borne arsenical resistance operon encodes an ATP-driven oxyanion pump for the extrusion of the oxyanions arsenite, antimonite and arsenate from bacterial cells. The catalytic component of the pump, the 63 kDa ArsA protein, hydrolyses ATP in the presence of its anionic substrate antimonite (SbO2-). The ATP analogue 5'-p-fluorosulphonylbenzoyladenosine was used to modify the ATP binding site(s) of the ArsA protein. From sequence analysis there are two potential nucleotide binding sites. Mutations were introduced into the N-terminal site. Purified mutant proteins were catalytically inactive and incapable of binding nucleotides. Conformational changes produced upon binding of substrates to the ArsA protein were investigated by measuring the effects of substrates on trypsin inactivation. The hydrophobic 45.5 kDa ArsB protein forms the membrane anchor for the ArsA protein. The presence of the ArsA protein on purified inner membrane can be detected immunologically. In the absence of the arsB gene no ArsA is found on the membrane. Synthesis of the ArsB protein is limiting for formation of the pump. Analysis of mRNA structure suggests a potential translational block to synthesis of the ArsB protein. Northern analysis of the ars message demonstrates rapid degradation of the mRNA in the arsB region.

Characterization of the catalytic subunit of an anion pump

The ArsA protein, the 63-kDa catalytic subunit of an oxyanion-translocating ATPase, was purified by successive chromatography using Q-Sepharose, red agarose, and phenyl-Sepharose to a specific activity in excess of 1 mumol of ATP hydrolyzed per min per mg of protein. ATPase activity was dependent on the presence of the oxyanionic substrates. Inhibitors of other classes of ion-translocating ATPases had no effect on ArsA ATPase activity, including N,N'-dicyclohexyl-carbodiimide, azide, vanadate, and nitrate. The apparent Km for ATP was determined to be 0.13 mM. The optimal pH range for ATP hydrolysis was 7.5 to 7.8. ATPase activity required Mg2+ at a molar ratio of 2 ATP:1 Mg2+. Limited proteolysis by trypsin was used to study conformational changes produced upon binding of substrates to the ArsA protein. In the absence of substrates, the ArsA protein was rapidly cleaved by trypsin to a major product of 30 kDa. ATP was partially protected from trypsin digestion, while the anionic substrate antimonite alone had no effect on proteolysis. Combination of the two substrates nearly completely protected the ArsA protein from proteolysis. Proteolytic cleavage correlated with loss of anion-stimulated ATPase activity and substrate protection from cleavage correlated with retention of activity. These results demonstrate that ATP and antimonite together produce a conformational change which is different from that of the ArsA protein in the presence of either substrate alone and suggest interaction between the oxyanion and ATP binding sites.

Lineage-specific regulation of the vasoactive intestinal peptide gene in neuroblastoma cells is conferred by 5.2 kilobases of 5'-flanking sequence

The expression of a transfected plasmid containing 5.2 kilobases (kb) of 5' regulatory DNA sequence of the human vasoactive intestinal peptide (VIP) gene attached to coding sequences of the reporter gene chloramphenicol acetyltransferase (CAT) was compared with endogenous VIP expression in subclones of the human neuroblastoma cell line SK-N-SH. These subclones vary widely in basal and inducible quantities of VIP and its precursor mRNA and can be interconverted under specified culture conditions. Endogenous VIP immunoreactivity, detectable in all subclones, was lowest in the neuronal subclone SH-SY-5Y, whereas 15- to 25-fold higher levels were observed in the epithelial-appearing SH-EP and intermediate SH-IN subclones. Treatment with 10 nM phorbol 12-myristate 13-acetate (PMA) stimulated VIP peptide levels approximately 5-fold in SH-SY-5Y cells but did not increase appreciably VIP levels in the other subclones. Treatment with 2.5 microM forskolin resulted in less than 50% stimulation of VIP expression in all subclones. Levels of mRNA encoding the VIP precursor generally paralleled these differences in VIP immunoreactivity. In cells transfected with the VIP/CAT fusion gene, CAT activity reflected closely these differences in basal VIP expression and the changes in response to PMA and forskolin. Deletion of 2.7 kb of the most upstream sequences resulted in an 80-90% reduction in basal CAT activity in SH-IN, but not SH-SY-5Y cells, and resulted in an 80% reduction in PMA stimulation in SH-SY-5Y cells. Deletion to within 74 nucleotides of the transcription start site resulted in CAT expression in SH-IN cells that was only 3% of that seen with the full 5.2-kb flanking sequences and further diminished the remaining PMA responsiveness in SH-SY-5Y cells. The data indicate that important cell-type-specific transcription regulatory sequences reside greater than 2.5 kb upstream from the VIP transcription start site.

Chromogranin A synthesis and secretion in chromaffin cells

A sensitive and selective radioimmunoassay for chromogranin A (Chrg A) has been developed to quantitate content, release, and biosynthesis of this secretory protein in neuroendocrine tissues. An antiserum raised against Chrg A from bovine adrenal medulla was found to detect predominantly only the Mr 70-75 kilodalton Chrg A in its native form, allowing the use of this antiserum as a quantitatively specific probe for Chrg A in cell-free extracts of the adrenal medulla and chromaffin cells. Chrg A comprises about 10% of the total protein of the chromaffin cell. It is released in parallel with Met-enkephalin and catecholamines from the bovine chromaffin cell in primary culture in response to nicotine and nicotinic cholinergic agonists. From 14 to 22% of total Chrg A is released from the cell during a 15-min exposure to a maximally stimulatory dose of nicotine (10-100 microM). Chrg A release on nicotinic stimulation is blocked by D-600 and hexamethonium to the same extent as Met-enkephalin and catecholamine release. The parallel time course and percent release of Chrg A and Met-enkephalin indicate that these secretory polypeptides are contained in, and released from, functionally identical cellular compartments. Chrg A and Met-enkephalin pentapeptide sequences are present in the chromaffin cell at a ratio of about 2:1, although Chrg A is far more abundant on a mass basis. Chrg A and Met-enkephalin biosynthesis appear to be differentially regulated within the chromaffin cell, since chronic treatment of cells with nicotine and forskolin causes an elevation of Met-enkephalin pentapeptide without a concomitant elevation of intracellular levels of Chrg A.