Pharmacokinetics and pharmacodynamics of GS-9350: a novel pharmacokinetic enhancer without anti-HIV activity

GS-9350 is a new chemical entity under development as a potent, mechanism-based inhibitor of human cytochrome P450 3A (CYP3A) isoforms. Its intended use is to increase the systemic exposure of coadministered agents that are metabolized by CYP3A enzymes. Unlike ritonavir, which is in current clinical use for this purpose, GS-9350 is devoid of anti-HIV activity. The pharmacokinetics of GS-9350 and its efficacy in increasing systemic exposure of the probe CYP3A substrate midazolam were examined in a study involving single- and multiple-dose escalations of GS-9350 from 50 to 400 mg. Single-dose escalation from 50 to 400 mg resulted in a 164-fold increase in GS-9350 exposure, whereas multiple-dose escalation in the dosage range of 50-300 mg resulted in a 47-fold increase in exposure. GS-9350 potently inhibited midazolam apparent clearance (95% reduction), similar in effect to ritonavir 100 mg. GS-9350 was generally well tolerated at all doses, and there was no evidence of dose-limiting toxicity. Establishing proof-of-concept, GS-9350 is currently under phase II development as a potential alternative to ritonavir for use with antiretroviral agents (including the HIV integrase inhibitor elvitegravir) that are often prescribed along with a "booster" drug.

Preparation and immune activity analysis of H5N1 subtype avian influenza virus recombinant protein-based vaccine

Avian influenza is a severe disease among farmed poultry and free-living birds and a constant threat to the commercial chicken industry around the world. Hemagglutinin (HA) is the major immunogen on the envelope of influenza A virus and is the predominant inducer of neutralizing antibody. To obtain the bioactive antigen proteins in large quantities, a new protein expression vector pBCX was constructed, which is based on the pET32a vector. The HA gene of the H5N1 subtype of avian influenza virus (AIV) was inserted into the pBCX vector and expressed efficiently in Escherichia coli BL21 (DE3). Fused expression of the exogenous gene and msyB produced a 97-kDa msyB-HA fusion protein. Sodium dodecyl sulfate-PAGE combined with scanning analysis demonstrated that the msyB-HA fusion protein accounted for 29.5% of the total bacterial protein, 90.5% being soluble. The msyB-HA fusion protein was purified with nondenaturing 50% Ni-NTA column chromatography, and the result showed that 24 mg of purified msyB-HA fusion protein could be obtained from 1 L of induced expression bacterial culture medium. The comparative results in the present study showed that pBCX was superior to pET32a as a protein expression vector. Western blotting showed the recombinant msyB-HA (rHA) to have better antigenic activity, which may be the result from the better posttranslation protein modification and folding in the pBCX expression system. With the rHA fusion protein as antigen, we successfully prepared and screened specific monoclonal antibodys against the H5N1 subtype AIV, which indicated that the rHA had antigen epitopes and biofunctions. The immune test confirmed that the rHA protein vaccine could also induce high neutralizing antibodies, and the AIV challenge test proved that the rHA protein-based vaccine could prevent the corresponding infection. This study demonstrates that the recombinant HA protein produced by the pBCX expression system could be used as a recombinant protein-based vaccine and has potential for further development for diagnosis.

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.

Ionic Dissolution Products of NovaBone® Promote Osteoblastic Proliferation via Influences on the Cell Cycle

This study investigated the effects of the ionic dissolution products of NovaBone® on osteoblastic proliferation and cell cycle regulation. MG63 osteoblast-like cells were cultured in NovaBone®-conditioned Dulbecco's Modified Eagle's Medium (DMEM) or control DMEM for 10 days. The concentration of silicon ions was significantly higher in NovaBone®-conditioned DMEM than control DMEM. MG63 cells cultured in NovaBone®-conditioned DMEM exhibited greater proliferation on days 1 and 4 than control cells. There were increased proportions of Novabone®-conditioned DMEM-cultured cells in the S and G2/M phases, and decreased proportions in the G0/G1 phase on days 1 and 4 versus control cells, while no differences were observed on days 7 and 10 between the two groups. Bone morphogenic protein 2 production increased in both groups, but was significantly higher for the NovaBone®-conditioned DMEM-cultured cells on day 10 compared with the controls. In conclusion, the NovaBone® ionic dissolution products, particularly the silicon ions, promoted proliferation of MG63 osteoblast-like cells in vitro via influences on the cell cycle.

Integrative review of international nursing research in Mainland China

BACKGROUND

Nursing research in Mainland China is divided into two parts: domestic nursing research, comprising all publications in Chinese; and international nursing research, comprising all publications in English. Domestic nursing research has been developing rapidly, demonstrated by the increase in new national or regional journals and publications. However, little is known about the extent of international research.

AIMS

To outline the development of international nursing research publications in Mainland China and to provide suggestions for future development.

METHOD

All of the papers were retrieved from PubMed. The key search phase was 'China or P.R.China NOT Hong Kong NOT Taiwan NOT Macao [AD]', with the limits of 'English', 'nursing journals' as well as the published date up to '2007/09/30'.

FINDINGS

PubMed recorded 57 English papers that were originally conducted in Mainland China during the search period from 1989 to 30 September 2007. Thirty-seven of the total 57 (65%) publications were contributed by Beijing, Shanghai and Hubei. Forty-four of the 57 publications were conducted with collaborators from Hong Kong, the USA, the UK and Canada. Thirteen publications were funded by international societies, while only three were funded by the Chinese government. The research topics mainly focused on clinical research, nursing education and nursing management.

CONCLUSIONS AND IMPLICATIONS

This study indicates that international nursing research has been growing slowly in Mainland China along with provincial variations. The suggestions to improve nursing research include the reform of nursing education, the enhancement of the collaboration with the international societies and the establishment of research priorities.

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.

Is the relationship between syndromes of depression and dementia temporal? The MRC-ALPHA and Hefei-China studies

BACKGROUND

Recent studies have shown a temporal association between depressive symptoms and cognitive decline. However, the relationship between syndromes of depression and dementia is unknown.

METHOD

A total of 1736 people aged > or = 65 years in China and 5222 older people in the UK were interviewed using the Geriatric Mental State Examination (GMS) and reinterviewed at follow-up. Five levels of syndromes of depression and dementia were diagnosed using the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT).

RESULTS

Although there were fewer depressive syndromes in Chinese than British participants, both populations showed a similarly high level of syndromes of dementia (organic disorder) (20% for women, 14% for men). There was a significant cross-sectional correlation between syndrome levels of depression and dementia (correlation coefficients: 0.141-0.248 for Chinese, 0.168-0.248 for British). This was maintained for different age, gender and people with and without cardiovascular disease (CVD). The relationship between syndromes of baseline depression and follow-up dementia was less substantial: the correlation coefficient was 0.075 [95% confidence interval (CI) 0.021-0.128] for the Chinese sample at the 1-year follow-up, and 0.093 (95% CI 0.061-0.125) for the British at the 2-year follow-up and 0.093 (95% CI 0.049-0.130) at the 4-year follow-up. This relationship disappeared in participants without baseline organic syndromes. In a multiple adjusted logistic regression analysis, an increased risk of organic syndromes seemed to be associated with baseline, mainly in the highest level of, depressive syndromes.

CONCLUSIONS

The relationship between syndromes of depression and dementia might be temporal. The lack of an obvious dose-response relationship between baseline depressive syndromes and follow-up dementia syndromes suggests that the causal relationship between depression and dementia needs further investigation.

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.

Self-assembling peptide nanofiber as potential substrates in islet transplantation

Hypoxia and reoxygenation (H/R)-induced damage often happens soon after islets are transplantation. The process of islet isolation and purification causes the rapid onset of hypoxia. We sought to develop a functional scaffold to sustain the structure and function of islets as well as to recover some of the surface molecules damaged during isolation, seeking to improve islet transplantation outcomes. Self-assembling peptide nanofiber (SAPNF), a new type of substrate has been shown to be an excellent biological material for neuronal cell culture and tissue engineering in animals. In this study, we investigated the protective effect of SAPNF on damage to rat islets. Freshly prepared rat islets from male Sprague-Dawley rats were seeded in plates coated with (SAPNF-treated group) or without (control group) SAPNF. The islets were then divided into two groups culture under normoxia for 7 days versus exposure to hypoxia (< 1% O2) for 6 hours followed by reoxygenation for 24 hours. The results showed that SAPNF exhibited improving effects on viability and function of cultured islets, protecting the one from H/R-induced damage. In both groups, the stimulation index of SAPNF-treated groups were about two times the controls. SAPNF treatment decreased apoptotic rates of islet cells. These results suggested the usefulness of SAPNF to maintain the viability and function of rat pancreatic islets. SAPNF may be a potential scaffold for clinical islet transplantation.

Inhibition of orotidine 5'-monophosphate decarboxylase and its therapeutic potential

Orotidine 5'-monophosphate decarboxylase (ODCase) is among the most proficient enzymes, and catalyzes the decarboxylation of OMP to UMP. An overview of ODCase and various proposals for its catalytic mechanism of decarboxylation are briefly presented here. A number of inhibitors of ODCase and new developments in the X-ray structures of ODCases from different species are discussed in the context of their therapeutic potential against cancer and infectious diseases. Latest discoveries in the inhibition of ODCase, for example using the novel C6 substitutions on the uridine, open new doors for drug discovery targeting parasitic diseases such as malaria.

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.

Effect of hyperbaric oxygen on patients with traumatic brain injury

Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of oxygen at a higher atmospheric pressure. The United States Food and Drug Administration have approved several clinical applications for HBOT, but HBOT in traumatic brain injury (TBI) patients has still remained in controversial. The purpose of our study is to evaluate the benefit of HBOT on the prognosis of subacute TBI patients. We prospectively enrolled 44 patients with TBI from November 1, 2004 to October 31, 2005. The study group randomly included 22 patients who received HBOT after the patients' condition stabilization, and the other 22 corresponding condition patients were assigned into the matched control group who were not treated with HBOT. The clinical conditions of the patients were evaluated with the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT. The GCS of the HBOT group was improved from 11.1 to 13.5 in average, and from 10.4 to 11.5 (p < 0.05) for control group. Among those patients with GOS = 4 before the HBOT, significant GOS improvement was observed in the HBOT group 6 months after HBOT. Based on this study, HBOT can provide some benefits for the subacute TBI patients with minimal adverse side effects.

Impact on mortality following first acute myocardial infarction of distance between home and hospital: cohort study

Objective:

To investigate the effect of distance between home and acute hospital on mortality outcome of patients experiencing an incident myocardial infarction (MI).

Design:

Cohort study using a record linkage database.

Setting:

Tayside, Scotland, UK.

Patients:

10 541 patients with incident acute MI between 1994 and 2003 were identified from Tayside hospital discharge data and from death certification data.

Main outcome measures:

MI mortality in the community, all-cause mortality in hospital and all-cause mortality during follow-up.

Results:

4133 subjects died following incident MI in the community (that is, were not hospitalised), 6408 patients survived to be hospitalised and 1010 of these (15.8%) died in hospital. Of 5398 discharged from hospital, 1907 (35.3%) died during a median of 3.2 years of follow-up. After adjustment for rurality and other known risk factors, distance between home and admitting hospital was significantly associated with increased mortality both before hospital admission (adjusted odds ratio (OR), 2.05, 95% CI 1.00 to 4.21 for >9 miles and 1.46, 1.09 to 1.95 for 3–9 miles when compared to <3 miles) and after hospitalisation (adjusted hazard ratio (HR) 1.90, 1.19 to 3.02 and 1.27, 0.96 to 1.68). However, there was no effect of distance on in-hospital mortality (adjusted OR 0.95, 0.45 to 2.03 and 1.02, 0.66 to 1.58).

Conclusion:

The distance between home and hospital of admission may predict mortality in subjects experiencing a first acute MI. This association was found both before and after hospitalisation. Further studies are needed to explore the reasons for this association. However these data provide support for policies that locate services for acute MI closer to where patients live.

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.

First Report of Aloe Root and Stem Rot in China Caused by Fusarium solani

During the springs of 2003 and 2004, a serious outbreak of root and stem disease occurred on Aloe barbadensis L. grown in commercial fields in Yuanjiang, Yunnan Province, Southwest China. The disease began with brown root rots that advanced to collars and stems, followed by internal decay of the lower stem. Diseased tissue samples collected from plants in different fields were surface disinfested and plated on potato dextrose agar (PDA). A Fusarium species was consistently isolated, and pure cultures were established by initiating new cultures with single spores. Grayish white and fluffy mycelium with a deep violet-blue pigment developed on PDA agar, with a growth rate of 3.4 cm in 3 days, and a dark, blue-green mass of confluent sporodochia or pionnotes covering the central part of the culture. Microconidia in false heads on long phialides were abundant when initially isolated but were infrequent in later cultures. Microconidia were generally single celled, oval to kidney shaped, and 8 to 16 × 2.5 to 4 μm. Macroconidia were abundant, cylindrical, slightly curved with blunt and rounded apical cells, and foot-shaped or notched basal cells, and mostly three to four septate, 27 to 50 × 3.6 to 5.7 μm. Chlamydospores were sparse, single or in short chains, thick walled, and 7 to 10 μm in diameter. This description corresponds to Fusarium solani (Mart.) Appel & Wollenw. emend. Snyd. & Hans as described by Nelson et al. (1). Inoculations with F. solani were made by dipping healthy aloe roots into a 300-ml suspension of 3 × 10⁵ conidia/ml. Control plants were dipped in sterile water. All plants were potted in soil and kept in a greenhouse (2). After 30 days, all inoculated plants developed root rots followed by collar and stem rots that were similar to those observed in the field. Cultures of F. solani were reisolated from the diseased plants and identification was confirmed by conidial characteristics. No symptoms were observed on the control plants. Tests were repeated with similar results. In China, the Yunnan Province produces one-third of all aloe grown and this disease has a major impact on production. Aloe is grown in certified organic fields and chemical pesticides are not used. To our knowledge, this is the first report of F. solani causing root and stem rot of A. barbadensis. References: (1) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, PA, 1983. (2) X. Ruan et al. Pages 211-215 in: Phytopathology Laboratory of Yunnan Province. Vol. 2. Y. Y. Shengfu, ed. Yunnan Science and Technology Press, Kunming, Yunnan, China, 1998.

Design optimization of flattop interleaver and its dispersion compensation

The objective of this paper is to present a general strategy for design optimization of flattop interleavers, and dispersion compensation for the interleavers, in order to achieve superior optical performance. The interleaver is formed by two multi-cavity Gire-Tournois etalons (MC-GTE) in a Michelson Interferometer (MI). An interleaver that has m cavities in one etalon and n cavities in the other is called an mn-GTE interleaver. Our optimization strategy exploits the general flattop condition and the technique of ripple equalization. Any mn-GTE interleaver may be optimized. The spectral performance can be greatly improved by the optimization process. As an illustration, we present a comprehensive analysis for a 11-GTE and a 21-GTE interleaver. The analytical expressions for flattop conditions, peak and trough positions are derived for optimization. The optimal performance of the interleavers can be controlled by the reflection coefficients and the parameters m and n. To achieve low-dispersion mn-GTE flattop interleavers, we propose to use one additional MC-GTE as a dispersion compensator to compensate for the chromatic dispersion. The analytical expressions of group delays and chromatic dispersions for an MC-GTE interleaver are derived. The optimization strategy of dispersion-ripple equalization is explained. The results show that the dispersion performance can be tailored by changing the reflection coefficients of the MC-GTE, and the dispersion and bandwidth can be enhanced by increasing the number of cavities of the MC-GTE.