Lead-induced hypertension. III. Increased hydroxyl radical production

Lead-induced hypertension has previously been shown to be closely associated with an increase in reactive oxygen species in low lead (100 ppm)-treated rats. The present study has attempted to define the specific moiety involved by noting the blood pressure (BP), reactive oxygen species (MDA-TBA), hydroxyl radical, and nitrotyrosine responses to infusion of the reactive oxygen species scavenger dimethylthiourea. Dimethylthiourea, a reputed scavenger of hydroxyl radical, normalized BP and MDA-TBA in the lead-treated rats but had no effect in normal control animals. MDA-TBA, hydroxyl radical, and nitrotyrosine, the tissue end product of peroxynitrite, were reduced to or toward normal by dimethylthiourea. The results, therefore, are consistent with the suggestion that either hydroxyl radical or peroxynitrite may be the reactive species affected by lead.

Characterization of 19 disease-associated missense mutations in the regulatory domain of the cystic fibrosis transmembrane conductance regulator

In order to gain a better insight into the structure and function of the regulatory domain (RD) of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, 19 RD missense mutations that had been identified in patients were functionally characterized. Nine of these (I601F, L610S, A613T, D614G, I618T, L619S, H620P, G628R and L633P) resulted in aberrant processing. No or a very small number of functional CFTR proteins will therefore appear at the cell membrane in cells expressing these mutants. These mutations were clustered in the N-terminal part of the RD, suggesting that this subdomain has a folding pattern that is very sensitive to amino acid changes. Mutations that caused no aberrant processing were further characterized at the electrophysiological level. First, they were studied at the whole cell level in Xenopus laevis oocytes. Mutants that induced a whole cell current that was significantly different from wild-type CFTR were subsequently analysed at the single channel level in COS1 cells transiently expressing the different mutant and wild-type proteins. Three mutant chloride channels, G622D, R792G and E822K CFTR, were characterized by significantly lower intrinsic chloride channel activities compared with wild-type CFTR. Two mutations, H620Q and A800G, resulted in increased intrinsic chloride transport activities. Finally, T665S and E826K CFTR had single channel properties not significantly different from wild-type CFTR.

A novel non-peptidyl growth hormone secretagogue

Direct screening of preselected compounds in a rat primary pituitary cell culture assay, followed by chemical modification of selected pharmacophores led to the identification of a novel non-peptidyl class of GH secretagogues (substituted benzolactams). The prototype compound of this class, L-692,429, stimulated GH release from rat primary pituitary cells in a time- and dose-dependent manner with an EC50 value of 60 nM. Under the same conditions, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GH-releasing peptide, GHRP-6) and GH-releasing factor (GRF) had EC50 values of 10(-8) and 5 x 10(-10) M, respectively. L-692,428, the S-enantiomer, of L-692,429, was inactive at a concentration as high as 2 microM. GH release induced by L-692,429 was inhibited by somatostatin as well as by GHRP-6 and substance P antagonists but not by GRF or opiate antagonists. L-692,400, which is structurally related to L-692,429 but biologically inactive, inhibited GH response not only to L-692,429 but also GHRP-6. Like GHRP-6, L-692,429 alone had no effect on intracellular cAMP levels; however, it synergized with GRF to further increase both the accumulation of cAMP and the release of GH. Maximal effects of L-692,429 and GHRP-6 on GH release were comparable. Interestingly, when presented together in maximal concentrations, L-692,429 and GHRP-6 did not cause an additional GH release when compared with either secretagogue alone. L-692,429 had a small effect on prolactin release but not adrenocorticotropin.(ABSTRACT TRUNCATED AT 250 WORDS)

Proteinase-polymerase precursor as the active form of feline calicivirus RNA-dependent RNA polymerase

The objective of this study was to identify the active form of the feline calicivirus (FCV) RNA-dependent RNA polymerase (RdRP). Multiple active forms of the FCV RdRP were identified. The most active enzyme was the full-length proteinase-polymerase (Pro-Pol) precursor protein, corresponding to amino acids 1072 to 1763 of the FCV polyprotein encoded by open reading frame 1 of the genome. Deletion of 163 amino acids from the amino terminus of Pro-Pol (the Val-1235 amino terminus) caused a threefold reduction in polymerase activity. Deletion of an additional one (the Thr-1236 amino terminus) or two (the Ala-1237 amino terminus) amino acids produced derivatives that were 7- and 175-fold, respectively, less active than Pro-Pol. FCV proteinase-dependent processing of Pro-Pol in the interdomain region preceding Val-1235 was not observed in the presence of a catalytically active proteinase; however, processing within the polymerase domain was observed. Inactivation of proteinase activity by changing the catalytic cysteine-1193 to glycine permitted the production and purification of intact Pro-Pol. Biochemical analysis of Pro-Pol showed that this enzyme has properties expected of a replicative polymerase, suggesting that Pro-Pol is an active form of the FCV RdRP.

Sensitivity to tumor promotion of SENCAR and C57BL/6J mice correlates with oxidative events and DNA damage

Significant differences in sensitivity to multistage carcinogenesis have been noted between mice that are sensitive (SENCAR) and resistant (C57BL/6J) to 12-O-tetradecanoylphorbol-13-acetate (TPA). However, the mechanism of this sensitivity has not yet been established. Recent studies from this laboratory have shown that TPA significantly enhances formation of hydrogen peroxide (H2O2) and oxidized DNA bases in SENCAR mouse skin, as it increases the infiltration of polymorphonuclear leukocytes (PMNs), as quantitated by myeloperoxidase (MPO). In the studies reported here, we compared SENCAR and C57BL/6J mice with respect to TPA-mediated edema, hyperplasia, PMN infiltration, oxidant formation and oxidative DNA damage in mouse skin. Topical application of two TPA doses (2x2-40 micrograms, 20 h apart) dose-dependently increased PMN infiltration and oxidant formation in both mouse strains, which was consistent with TPA-induced morphological alterations (edema and hyperplasia). However, at low TPA doses (2-4 micrograms), the increases over controls in the SENCAR mice were significantly greater (P < 0.01) than those in C57BL/6J mice. Comparison of the net values indicated that 4 micrograms TPA enhanced PMN infiltration (MPO units/cm2) and oxidant formation (nmol H2O2/cm2) in SENCAR mice by 7.7- and 11-fold respectively over those present in TPA-treated C57BL/6J mouse skin. At the same dose, TPA also significantly increased formation of thymidine glycol (dTG; 5.5-fold), 5-hydroxymethyl-2'-deoxyuridine (HMdU; 4.9-fold) and 8-hydroxyl-2-deoxyguanosine (8-OHdG; 11.4-fold) in SENCAR mouse epidermis. Then, the levels of all three declined. In C57BL/6J mice, there were virtually no increases at 4 micrograms TPA, but their levels gradually increased with higher TPA doses and reached maxima at 10 micrograms TPA for dTG (1.9-fold increase), at 20 micrograms TPA for 8-OHdG (6.0-fold), and at 30 micrograms TPA for HMdU (1.8-fold). We conclude that the TPA-mediated oxidative events and oxidative DNA modification by different doses of TPA correlate with the promoting potencies of those doses in both mouse strains. Therefore, they could be, at least in part, responsible for the strain-dependent sensitivity to tumor promotion.

Downregulation of volume-activated Cl- currents during muscle differentiation

We have used the whole cell configuration of the patch-clamp technique to investigate volume-activated Cl- currents in BC3H1 and C2C12 cells, two mouse muscle cell lines that can be switched from a proliferating to a differentiated musclelike state. Reducing the extracellular osmolality by 40% evoked large Cl- currents in proliferating BC3H1 and C2C12 cells. These currents were outwardly rectifying and had an anion permeability sequence as follows: I- > Br- > Cl- >> gluconate. They were inhibited by >50% by flufenamic acid (500 microM), niflumic acid (500 microM), and 5-nitro-2-(3-phenylpropylamino)benzoic acid (100 microM) but were relatively insensitive to tamoxifen (100 microM). A reduction in the serum concentration in the culture medium induced growth arrest in both cell lines, and the cells started to differentiate into spindle-shaped nonfusing muscle cells (BC3H1) or myotubes (C2C12). This differentiation was accompanied by a drastic decrease in the magnitude of the volume-activated Cl- currents. The close correlation between volume-activated Cl- currents and cell proliferation suggests that these currents may be involved in cell proliferation.

Delayed xenograft rejection in the concordant hamster heart into Lewis rat model

The inability to provide an adequate supply of human organs for clinical transplantation has created a strong interest in the use of nonhuman, especially nonprimate, organs. The first biological obstacle confronting such discordant transplantations is a series of violent reactions that result in hyperacute rejection of the xenograft. Significant advances in controlling hyperacute rejection have been achieved recently through the generation of transgenic pig donors bearing human complement regulatory proteins. However, when hyperacute rejection is averted, the xenografts are rejected in 2-70 days in spite of high-dose immunosuppression, by a process collectively termed delayed xenograft rejection. Delayed xenograft rejection is characterized by a refractoriness to conventional immunosuppression, extensive xenoreactive antibody deposition, and cellular infiltration that is dominated by macrophages. We have examined the features of extended host and graft response in the concordant hamster-to-rat xenotransplant model, where such features have historically been obscured by early graft destruction. Hamster hearts transplanted into rats do not encounter hyperacute rejection but are rejected within 3-4 days when xenoreactive antibody titers rise exponentially to levels that elicit a classical antibody- and complement-mediated acute xenograft rejection. We have successfully blocked acute xenograft rejection by a combination of immunosuppressive agents, leflunomide, and cyclosporine. Stopping the immunosuppression resulted in graft rejection that is histologically characterized by extensive xenoreactive antibody deposition and cellular infiltration that is predominantly composed of macrophages. We have noted the similarities between the histopathology of rejection of long-surviving concordant xenografts and that described for discordant xenografts and refer to the process of rejection of concordant grafts that have escaped acute xenograft rejection, delayed xenograft rejection.

Decreased NURR1 and PITX3 gene expression in Chinese patients with Parkinson's disease

BACKGROUND AND PURPOSE

The preferential degeneration of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta is the pathological hallmark in Parkinson's disease (PD). The transcription factors NURR1 and PITX3 have been shown to play a crucial role in the maturation and survival of mDA neurons, and both of them were potential susceptibility genes for PD.

METHODS

  To determine whether NURR1 and PITX3 gene expression are altered in Chinese patients with PD, we measured their gene expression in human peripheral blood lymphocytes (PBL) in 255 patients with PD and 211 age- and gender-matched healthy controls by quantitative real-time PCR technique.

RESULTS

 We found that both NURR1 and PITX3 gene expression in PBL were significantly decreased in patients with PD as compared with controls (P < 0.0001). Lower levels of NURR1 and PITX3 gene expression were significantly associated with the increased risk for PD in male and older subjects, respectively.

CONCLUSIONS

  Our results provide useful information that the NURR1 and PITX3 gene expression is decreased in the PBL of Chinese patients with PD, indicating their possible systemic involvement in PD.

Intracranial pressure fluctuation during hemodialysis in renal failure patients with intracranial hemorrhage

Coagulopathy in renal failure patients often makes them vulnerable to intracranial hemorrhage. Emergency decompression to remove the hematoma and to stop bleeding is always indicated. After the surgery, hemodialysis (HD) should be arranged to maintain the BUN/Cr. level, and I/O balance. During HD, intracranial pressure in all of the patients in this study fluctuated. This phenomenon always resulted in neurological deterioration in acute or chronic renal failure. We present intracranial pressure (ICP) changes during HD in five acute or chronic renal failure patients with intracranial hemorrhage. They all underwent craniectomy or craniotomy with ICP monitors implantation. Different HD protocols were arranged for these patients and then we observed clinical results. ICP elevated during HD and resulted in severe brain swelling. This situation was one of the clinical presentations of dialysis disequilibrium syndrome (DDS). Four patients died because of this complication and one survived. ICP fluctuation seemed to be correlated with the fluid amount and frequency of HD. The prevalence and pathophysiology of DDS remain unclear. Renal failure patient with intracranial hemorrhage may be complicated with DDS when HD was performed. An attempt to reduce the fluid amount and to increase the frequency of HD might help these patients.

N-(9-(9-phenylfluorenyl))homoserine-derived cyclic sulfamidates: novel chiral educts for the synthesis of enantiopure gamma-substituted alpha-amino acids

(4S)-tert-Butyl 2,2-dioxo-3-PhF-1,2,3-oxathiazainane-4-carboxylate reacted effectively with nitrogen, sulfur, and oxygen nucleophiles to provide enantiopure (>97% ee) gamma-substituted alpha-amino acids. Reaction: see text.

Review of guidelines and literature for handling missing data in longitudinal clinical trials with a case study

Missing data in clinical trials are inevitable. We highlight the ICH guidelines and CPMP points to consider on missing data. Specifically, we outline how we should consider missing data issues when designing, planning and conducting studies to minimize missing data impact. We also go beyond the coverage of the above two documents, provide a more detailed review of the basic concepts of missing data and frequently used terminologies, and examples of the typical missing data mechanism, and discuss technical details and literature for several frequently used statistical methods and associated software. Finally, we provide a case study where the principles outlined in this paper are applied to one clinical program at protocol design, data analysis plan and other stages of a clinical trial.

Free radical-mediated neurotoxicity may be caused by inhibition of mitochondrial dehydrogenases in vitro and in vivo

We previously demonstrated that copper facilitated the formation of reactive oxygen species, and inhibited pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in animal models of Wilson's disease in vivo. However, direct Cu(2+) toxicity has only been demonstrated for Wilson's disease. We now hypothesize that inhibition of these mitochondrial dehydrogenases might also contribute to many other injuries and disorders that are reactive oxygen species-mediated. We have modeled reactive oxygen species-mediated injuries using inducers of reactive oxygen species such as hydrogen peroxide, ethacrynic acid or menadione, or another redox active metal (Cd(2+)). Here we demonstrated that these toxic exposures were accompanied by an early marked reduction in both pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase activities, followed by a decrease in neuronal mitochondrial transmembrane potential and ATP, prior to murine cortical neuronal death. Thiamine (6 mM), and dihydrolipoic acid (50 microM), required cofactors for pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase (thiamine as thiamine pyrophosphate), attenuated the reactive oxygen species-induced reductions in these enzyme activities, as well as subsequent loss of mitochondrial transmembrane potential and ATP, and neuronal death. We next tested the effect of thiamine supplementation on an in vivo model of reactive oxygen species-mediated injury, transient middle cerebral artery occlusion, and reperfusion in rats. Oral or i.p. thiamine administration reduced the middle cerebral artery occlusion-induced infarct. These data suggest that reactive oxygen species-induced neuronal death may be caused in part by reactive oxygen species-mediated inhibition of pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in vivo, and that thiamine or dihydrolipoic acid may constitute potential therapeutic agents not just against Cu(2+) neurotoxicity, but may reduce neuronal degeneration in the broader range of diseases mediated by free radical stress.

The association between coeliac disease and cardiovascular disease

BACKGROUND

Coeliac disease is more prevalent than was previously thought. The association between coeliac disease and cardiovascular outcome is not clear.

AIM

To investigate whether coeliac disease patients have an increased risk of cardiovascular events.

METHODS

A community-based cohort study using a record-linkage database. Three hundred and sixty-seven coeliac patients identified by a positive antiendomysial antibody test or a diagnosis with small bowel biopsy, and 5537 subjects who were tested and had a negative coeliac immunology, were included in the study.

RESULTS

The crude rates of cardiovascular events were 9.5 per 1000 person-years (95% CI: 4.4-14.6) in the coeliac cohort and 8.9 per 1000 person-years (95% CI: 7.6-10.3) in the antiendomysial antibody-negative cohort. Compared with the antiendomysial antibody-negative cohort, the adjusted relative risk of cardiovascular events for coeliac cohort was 1.9 (95% CI: 1.00-3.60). When we excluded patients who had previous hospitalization for cardiovascular disease, the adjusted relative risk was 2.5 (95% CI: 1.22-5.01). The use of any cardiovascular drugs prior to and after entry to the study were 36% and 29% for the coeliac cohort (P = 0.05), and 34% and 26% for the antiendomysial antibody-negative cohort (P < 0.01).

CONCLUSION

Our findings suggest that coeliac disease seems to be associated with an increased risk of cardiovascular outcome.

Citalopram enhances neurovascular regeneration and sensorimotor functional recovery after ischemic stroke in mice

Recent clinical trials have demonstrated that treatment with selective serotonin reuptake inhibitors after stroke enhances motor functional recovery; however, the underlying mechanisms remain to be further elucidated. We hypothesized that daily administration of the clinical drug citalopram would produce these functional benefits via enhancing neurovascular repair in the ischemic peri-infarct region. To test this hypothesis, focal ischemic stroke was induced in male C57/B6 mice by permanent ligation of distal branches of the middle cerebral artery to the barrel cortex and 7-min occlusion of the bilateral common carotid arteries. Citalopram (10mg/kg, i.p.) was injected 24h after stroke and daily thereafter. To label proliferating cells, bromo-deoxyuridine was injected daily beginning 3 days after stroke. Immunohistochemical and functional assays were performed to elucidate citalopram-mediated cellular and sensorimotor changes after stroke. Citalopram treatment had no significant effect on infarct formation or edema 3 days after stroke; however, citalopram-treated mice had better functional recovery than saline-treated controls 3 and 14 days after stroke in the adhesive removal test. Increased expression of brain-derived neurotrophic factor was detected in the peri-infarct region 7 days after stroke in citalopram-treated animals. The number of proliferating neural progenitor cells and the distance of neuroblast migration from the sub-ventricular zone toward the ischemic cortex were significantly greater in citalopram-treated mice at 7 days after stroke. Immunohistochemical staining and co-localization analysis showed that citalopram-treated animals generated more new neurons and microvessels in the peri-infarct region 21 and 28 days after stroke. Taken together, these results suggest that citalopram promotes post-stroke sensorimotor recovery likely via enhancing neurogenesis, neural cell migration and the microvessel support in the peri-infarct region of the ischemic brain.

Association between allopurinol and mortality in heart failure patients: a long-term follow-up study

AIMS

The aim of the study was to explore the long-term effect of allopurinol on mortality and cardiovascular hospitalisations in heart failure (HF) patients.

METHODS

This is a population-based cohort study using a record-linkage database in Tayside, Scotland. A total of 4785 HF patients (4260 non-users, 267 incident users and 258 prevalent users) were studied between 1993 and 2002.

RESULTS

Compared with non-users, low-dose users in the incident group had a significant increased risk of all-cause mortality, cardiovascular mortality and cardiovascular recurrence (adjusted HR, 1.60, 95%CI 1.26-2.03; 1.70, 1.29-2.23 and 1.44, 1.01-2.07). For the prevalent users, the adjusted HR were 1.27, 0.98-1.64; 1.43, 1.07-1.90 and 1.27, 0.91-1.76 respectively. There was no increased risk of outcome for high-dose users when compared with non-users (adjusted HR, 1.18, 0.84-1.66; 1.14, 0.76-1.71 and 1.36, 0.88-2.10 for the incident users, and 0.86, 0.64-1.15; 0.90, 0.64-1.26; and 1.27, 0.93-1.74 for the prevalent users respectively). High-dose allopurinol was associated with reduced risk of all-course mortality for prevalent users when compared with low-dose (adjusted HR 0.65, 95%CI 0.42-0.99).

CONCLUSIONS

The prevalent high-dose allopurinol use had a lower risk of mortality than the prevalent low-dose use suggesting that allopurinol may be of benefit in HF patients.

Nicotine raises the influx of permeable solutes across the rat blood-brain barrier with little or no capillary recruitment

Nicotine (1.75 mg/kg s.c.) was administered to rats to raise local CBF (lCBF) in various parts of the brain, test the capillary recruitment hypothesis, and determine the effects of this increase in lCBF on local solute uptake by brain. lCBF as well as the local influx rate constants (K1) and permeability-surface area (PS) products of [14C]antipyrine and [14C]-3-O-methyl-D-glucose (3OMG) were estimated by quantitative autoradiography in 44 brain areas. For this testing, the finding of significantly increased PS products supports the capillary recruitment hypothesis. In 17 of 44 areas, nicotine treatment increased lCBF by 30-150%, K1 of antipyrine by 7-40%, K1 of 3OMG by 5-27%, PS product of antipyrine by 0.20% (mean 7%), and PS product of 3OMG by 0-23% (mean 8%). Nicotine had no effect on blood flow or influx in the remaining 27 areas. The increases in lCBF and K1 of antipyrine were significant, whereas those in K1 of 3OMG and in PS for both antipyrine and 3OMG were not statistically significant. The lack of significant changes in PS products implies that in brain areas where nicotine increased blood flow: (a) essentially no additional capillaries were recruited and (b) blood flow within brain capillary beds rises by elevating linear velocity. The K1 results indicate that the flow increase generated by nicotine will greatly raise the influx and washout rates of highly permeable materials, modestly elevate those of moderately permeable substances, and negligibly change those of solutes with extraction fractions of < 0.2, thereby preserving the barrier function of the blood-brain barrier.

Acute and delayed protective effects of pharmacologically induced hypothermia in an intracerebral hemorrhage stroke model of mice

Hemorrhagic stroke, including intracerebral hemorrhage (ICH), is a devastating subtype of stroke; yet, effective clinical treatment is very limited. Accumulating evidence has shown that mild to moderate hypothermia is a promising intervention for ischemic stroke and ICH. Current physical cooling methods, however, are less efficient and often impractical for acute ICH patients. The present investigation tested pharmacologically induced hypothermia (PIH) using the second-generation neurotensin receptor (NTR) agonist HPI-201 (formerly known as ABS-201) in an adult mouse model with ICH. Acute or delayed administrations of HPI-201 (2mg/kg bolus injection followed by 2 injections of 1mg/kg, i.p.) were initiated at 1 or 24h after ICH. HPI-201 induced mild hypothermia within 30 min and body and brain temperatures were maintained at 32.7 ± 0.4°C for at least 6h without causing observable shivering. With the 1-h delayed treatment, HPI-201-induced PIH significantly reduced ICH-induced cell death and brain edema compared to saline-treated ICH animals. When HPI-201-induced hypothermia was initiated 24h after the onset of ICH, it still significantly attenuated brain edema, cell death and blood-brain barrier breakdown. HPI-201 significantly decreased the expression of matrix metallopeptidase-9 (MMP-9), reduced caspase-3 activation, and increased Bcl-2 expression in the ICH brain. Moreover, ICH mice received 1-h delayed HPI-201 treatment performed significantly better in the neurological behavior test 48 h after ICH. All together, these data suggest that systemic injection of HPI-201 is an effective hypothermic strategy that protects the brain from ICH injury with a wide therapeutic window. The protective effect of this PIH therapy is partially mediated through the alleviation of apoptosis and neurovascular damage. We suggest that pharmacological hypothermia using the newly developed neurotensin analogs is a promising therapeutic treatment for ICH.

Long-term efficacy of single-dose radiofrequency-induced heat therapy vs. intralesional antimonials for cutaneous leishmaniasis in India

BACKGROUND

Radiofrequency-induced heat therapy (RFHT) has been found to be safe and effective against cutaneous leishmaniasis (CL) in the short term, but its long-term efficacy is unclear.

OBJECTIVES

To compare the long-term efficacy of RFHT vs. intralesional sodium stibogluconate (SSG) injections in the treatment of CL in India.

METHODS

One hundred patients with a confirmed diagnosis of CL were randomly assigned in a 1 : 1 ratio to receive topical RFHT for 30-60 s or seven intralesional injections of SSG (50 mg cm(-2) of lesion). Improvement and recurrence were monitored every 15 days after the initiation of treatment for 4 months and then at 5, 6, 9, 12 and 18 months post-treatment; the rates of complete cure were compared.

RESULTS

Lesions were healed in 47 out of 50 patients (94%) in the RFHT group and in 46 out of 50 patients (92%) in the SSG group at week 12. Time to complete healing was comparable in the two groups. At 6 months post-treatment, cure rates in the RFHT and SSG groups were 98% [95% confidence interval (CI) 94-100%] and 94% (95% CI 86-100%), respectively. Age, sex and lesion size or number had no effect on cure rates. No relapse of infection was recorded in cured patients in either group up to 12-18 months after initiation of treatment. Skin biopsies of cured lesions in eight out of eight (100%) patients from the RFHT group and three of three from the SSG group at 12 months showed minimal fibrosis and were negative for Leishmania tropica by polymerase chain reaction test.

CONCLUSIONS

A single application of RFHT is safe, cosmetically acceptable and effective in inducing a long-term cure of CL.

A comparison between B-type natriuretic peptide, global registry of acute coronary events (GRACE) score and their combination in ACS risk stratification

BACKGROUND

In acute coronary syndrome (ACS), both the Global Registry of Acute Coronary Events (GRACE) score and B-type natriuretic peptide (BNP) predict cardiovascular events. However, it is unknown how BNP compares with GRACE and how their combination performs in ACS.

METHODS

The authors recruited 449 consecutive ACS patients and measured admission GRACE score and bedside BNP levels. The main outcome measure was all-cause mortality, readmission with ACS or congestive heart failure (defined as a cardiovascular event) at 10 months from presentation.

RESULTS

Of the 449 patients, 120 patients presented with ST-elevation myocardial infarction (MI) (27%). There were 90 cardiovascular events at 10 months. Both higher GRACE terciles and higher BNP terciles predicted cardiovascular events. There was a significant but only partial correlation between the GRACE score and log BNP (R = 0.552, p<0.001). On multivariate analyses, after adjusting for the GRACE score itself, increasing BNP terciles independently predicted cardiovascular events (second BNP tercile adjusted RR 2.28 (95% CI 1.15 to 4.51) and third BNP tercile adjusted RR 4.91 (95% CI 2.62 to 9.22)). Patients with high GRACE score-high BNP were more likely to experience cardiovascular events at 10 months (RR 6.00 (95% CI 2.40 to 14.83)) compared to those with high GRACE score-low BNP (RR 2.40 (95% CI 0.76 to 7.56)).

CONCLUSION

In ACS, most but not all of our analyses suggest that BNP can predict cardiovascular events over and above the GRACE score. The combined use of both the GRACE score and BNP can identify a subset of ACS patients at particularly high risk. This implies that both the GRACE score and BNP reflect somewhat different risk attributes when predicting adverse prognosis in ACS and their synergistic use can enhance risk stratification in ACS to a small but potentially useful extent.

A case-control study of nasopharyngeal carcinoma in the high background radiation areas of Yangjiang, China

The main purposes of this study were to identify the major determinants of nasopharyngeal carcinoma (NPC) in the high-background radiation areas (HBRA) in Yangjiang, China and to evaluate their potential confounding effects on the NPC risk associated with exposure to high background radiation. A matched case-control study was conducted using those who died of NPC during the period 1987-1995. Two controls were randomly selected for each case from those who died from causes other than malignancies and external causes. Cases and their controls were matched with respect to sex and the years of birth and death (+/- 5 years). Study subjects' next-of-kin were interviewed using a standardized questionnaire to collect information on socioeconomic status, dietary habits, tobacco smoking and alcohol consumption, disease history, pesticide use, medical X-ray exposure, the family history of NPC and so on. We succeeded in interviewing 97 cases and 192 controls. Univariate conditional logistic regression analysis showed that NPC risk was associated with the consumption of salted fish, homemade pickles, and fermented soy beans, education levels, the history of chronic rhinitis, and the family history of NPC. Multivariate conditional logistic regression analysis revealed that education levels (Odds ratio (OR) for middle school or higher levels vs. no school education = 3.8, 95% CI = 1.2 to 11.8), salted fish intake (OR = 3.2, 95% CI = 1.7 to 6.1), the history of chronic rhinitis (OR = 3.6, 95% CI = 1.3 to 10.1), and the family history of NPC (OR = 14.2, 95% CI = 2.7 to 73.4) were independent risk factors of NPC. Tobacco smoking (OR = 1.2, 95% CI = 0.7 to 2.1), and alcohol consumption (OR = 0.9, 95% CI = 0.5 to 1.9) were not significantly related to NPC risk. The ORs of NPC risk comparing HBRA and a nearby control area before and after adjustment for the major risk determinants identified in the present study were 0.86 (95% CI = 0.50 to 1.50) and 0.87 (95% CI = 0.45 to 1.67), respectively. Salted fish intake was a strong risk factor of NPC. Education, the history of chronic rhinitis and the family history of NPC were also related to NPC risk. The exposure to high background radiation in HBRA of Yangjiang was not related to NPC risk with or without the adjustment for those major risk determinants of NPC.

Instability of the amyloidogenic cystatin C variant of hereditary cerebral hemorrhage with amyloidosis, Icelandic type

A cystatin C variant with L68Q substitution and a truncation of 10 NH2-terminal residues is the major constituent of the amyloid deposited in the cerebral vasculature of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis (HCHWA-I). Variant and wild type cystatin C production, processing, secretion, and clearance were studied in human cell lines stably overexpressing the cystatin C genes. Immunoblot and mass spectrometry analyses demonstrated monomeric cystatin C in cell homogenates and culture media. While cystatin C formed concentration-dependent dimers, the HCHWA-I variant dimerized at lower concentrations than the wild type protein. Amino-terminal sequence analysis revealed that the variant and normal proteins produced and secreted are the full-length cystatin C. Pulse-chase experiments demonstrated similar levels of normal and variant cystatin C production and secretion. However, the secreted variant cystatin C exhibited an increased susceptibility to a serine protease in conditioned media and in human cerebrospinal fluid, explaining its depletion from the cerebrospinal fluid of HCHWA-I patients. Thus, the amino acid substitution may induce unstable cystatin C with intact inhibitory activity and predisposition to self-aggregation and amyloid fibril formation.

Nonlinear dust kinetic Alfven waves

Localized nonlinear dust kinetic Alfven waves are investigated. It is found that finite density dips and humps can coexist. The density humps are cusped and narrower than the dips.