Intravitreal conbercept for branch retinal vein occlusion induced macular edema: one initial injection versus three monthly injections

Background

To compare the efficacy of one initial intravitreal injection of conbercept (IVC) versus three monthly IVCs in patients with macular edema (ME) after branch retinal vein occlusion (BRVO). Both options were followed by a pro re nata (PRN) retreatment regimen.

Methods

This study retrospectively investigated and followed 60 patients with acute ME secondary to BRVO for over a year. 30 subjects received one initial injection (1 + PRN group); while, 30 received three monthly injections (3 + PRN group). The functional and anatomic outcomes were assessed during each follow-up.

Results

The general characteristics of the 60 subjects were as follows: mean [SD] age, 57.43 [13.06] years; 33 [55%] female; 36 [60%] non-ischemic form. Both groups showed a stable gain in visual acuity (VA) with similar logMAR (mean ± SD) (1 + PRN group 0.308 ± 0.399, 3 + PRN group 0.34 ± 0.352) during the first 12 months. Additionally, both groups exhibited a significant reduction in central foveal thickness (CFT) with no statistically significant difference between them (1 + PRN group 222.1 μm ± 197.1 μm, 3 + PRN group 228.4 μm ± 200.2 μm). Both treatment groups had similar improvements in logMAR and anatomic outcomes over time. The stratified analysis showed that patients with the non-ischemic form and those with the ischemic form had similar improvements in VA (0.346 ± 0.366 VS 0.29 ± 0.39, P = 0.575) during the 12 months follow-ups. The number of injections was lower in the 1 + PRN group (4.0 ± 1.6) than in the 3 + PRN group (4.7 ± 1.3) (P = 0.068). No adverse effects or unexpected safety issues were reported in either group.

Conclusions

Conbercept yielded significant improvements in VA and CFT among patients with BRVO induced ME, independent of their retinal ischemia status. The results showed that the 3 + PRN regimen do not lead to better functional outcomes or lower treatment needs in clinical practice as compared to the 1 + PRN regimen.

Effect of Rhizobium Symbiosis on Low-Temperature Tolerance and Antioxidant Response in Alfalfa (Medicago sativa L.)

Low temperature-induced stress is a major environmental factor limiting the growth and development of plants. Alfalfa (Medicago sativa L.) is a legume well known for its tolerance of extreme environments. In this study, we sought to experimentally investigate the role of rhizobium symbiosis in alfalfa's performance under a low-temperature stress condition. To do this, alfalfa "Ladak+" plants carrying active nodules (AN), inactive nodules (IN), or no nodules (NN) were exposed to an imposed low temperature stress and their survivorship calculated. The antioxidant defense responses, the accumulation of osmotic regulation substances, the cell membrane damage, and the expression of low temperature stress-related genes were determined in both the roots and the shoots of alfalfa plants. We found that more plants with AN survived than those with IN or NN under the same low temperature-stress condition. Greater activity of oxidation protective enzymes was observed in the AN and IN groups, conferring higher tolerance to low temperature in these plants. In addition, rhizobia nodulation also enhanced alfalfa's ability to tolerate low temperature by altering the expression of regulatory and metabolism-associated genes, which resulted in the accumulation of soluble proteins and sugars in the nodulated plants. Taken together, the findings of this study indicate that rhizobium inoculation offers a practical way to promote the persistence and growth potential of alfalfa "Ladak+" in cold areas.

Sodium-Related Adaptations to Drought: New Insights From the Xerophyte Plant Zygophyllum xanthoxylum

Understanding the unusual physiological mechanisms that enable drought tolerance in xerophytes will be of considerable benefit because of the potential to identify novel and key genetic elements for future crop improvements. These plants are interesting because they are well-adapted for life in arid zones; Zygophyllum xanthoxylum, for example, is a typical xerophytic shrub that inhabits central Asian deserts, accumulating substantial levels of sodium (Na+) in its succulent leaves while growing in soils that contain very low levels of this ion. The physiological importance of this unusual trait to drought adaptations remains poorly understood, however. Thus, 2-week-old Z. xanthoxylum plants were treated with 50 mM NaCl (Na) for 7 days in this study in order to investigate their drought tolerance, leaf osmotic potential (Ψs) related parameters, anatomical characteristics, and transpiration traits. The results demonstrated that NaCl treatment significantly enhanced both the survivability and durability of Z. xanthoxylum plants under extreme drought conditions. The bulk of the Na+ ions encapsulated in plants was overwhelmingly allocated to leaves rather than roots or stems under drought conditions; thus, compared to the control, significantly more Na+ compared to other solutes such as K+, Ca2+, Cl-, sugars, and proline accumulated in the leaves of NaCl-treated plants and led to a marked decrease (31%) in leaf Ψs. In addition, the accumulation of Na+ ions also resulted in mesophyll cell enlargement and leaf succulence, enabling the additional storage of water; Na+ ions also reduced the rate of water loss by decreasing stomatal density and down-regulating stomatal aperture size. The results of this study demonstrate that Z. xanthoxylum has evolved a notable ability to utilize Na+ ions to lower Ψs, swell its leaves, and decrease stomatal aperture sizes, in order to enable the additional uptake and storage of water and mitigate losses. These distinctive drought adaption characteristics mean that the xerophytic plant Z. xanthoxylum presents a fascinating case study for the potential identification of important and novel genetic elements that could improve crops. This report provides insights on the eco-physiological role of sodium accumulation in xerophytes adapted to extremely arid habitats.

[Distribution responses of Lespedeza davurica community on Loess Plateau to climate change]

Field survey and position monitoring were conducted from 2000 to 2009 to study the effects of climate change on the distribution and growth of Lespedeza davurica community on Loess Plateau. As affected by air temperature, the appropriate growth region of L. davurica community on the Plateau had an obvious zonal distribution from northwest to southeast. For the distribution of L. davurica community, the suitable air temperature was 7.4 degrees C-10 degrees C, average population density was 13.9 plants x m(-2), and reproductive branch was averagely 11.4 per cluster. As affected by precipitation gradient, the horizontal distribution of L. davurica community changed from a constructive or predominant species in typical grassland region into a companion species in forest steppe region, and then, the community gradually became dominant species. The L. davurica community appeared as an occasional species on the half sunny slope of gullies and valleys and the sand dunes in desert steppe region, and extended gradually from its optimal region with yearly precipitation 300 -500 mm to the region with yearly precipitation 270-600 mm. Also, the L. davurica community extended from its optimal altitude 1100-1700 m to 600-1950 m. Under the background of global climate change, the eco-breadth of L. davurica community expanded gradually.

A Comparative Efficacy and Safety Study of Long-Acting Risperidone Injection and Risperidone Oral Tablets Among Hospitalized Patients: 12-Week Randomized, Single-Blind Study

OBJECTIVE

The superiority of risperidone long-acting injection (RLAI) over oral typical and atypical antipsychotics demonstrated in previous studies may be related to the improved drug compliance. The aim of the 12-week randomized, single-blind study was to test whether the superiority of RLAI remained among hospitalized patients that drug compliance could be optimally controlled.

METHODS

Fifty hospitalized stable schizophrenic patients, who had maintained on oral risperidone for more than 3 months, were randomized to the RLAI and oral risperidone group. Finally 49 patients (98 %) completed the study, and no dose change of oral risperidone, or RLAI was noted among all patients.

RESULTS

The RLAI group showed significantly increased positive score of Positive and Negative Syndrome Scale (PANSS) than the risperidone group (0.72 +/- 3.52 vs. -1.24 +/- 3.81, p = 0.022), but without significance difference for the PANSS total, negative and general psychopathology scores. The RLAI group also showed a significantly improved Udvalg for Kliniske Undersogelser (UKU) Scale (p = 0.037), social life domains of Short-Form Health Survey (SF-36) (p = 0.011), and reduced prolactin level (p = 0.001).

CONCLUSION

The results indicated that with optimal controlling of drug compliance among hospitalized patients, RLAI showed no benefit of efficacy over oral risperidone, but with advantages of improved side-effect profiles, social life ratings, and reduced prolactin levels.

Novel single-point plasma or saliva dextromethorphan method for determining CYP2D6 activity

O-Demethylation of dextromethorphan co-segregates with 4-hydroxylation of debrisoquin and is used for CYP2D6 phenotyping. In most previous studies, 8-h urinary samples were collected for determining the dextromethorphan metabolic ratio (dextromethorphan/dextrorphan molar ratio). In addition, a salivary sampling at 3 h had been suggested for the phenotyping. To evaluate the repeatability and validity of previously reported and other potential phenotyping methods, we determined the metabolic ratios from urine samples (for various intervals), or from plasma or saliva (at varying time points) after repetitive single doses of immediate-release or repetitive multiple doses of controlled-release dextromethorphan preparations. For the single-dose study, each of 12 subjects received 15 mg of immediate-release dextromethorphan in period I and period II, respectively, with a 1-week washout period. For the multiple-dose study, each of 16 subjects received 60 mg controlled-release dextromethorphan twice daily for 5 days in period I and period II, respectively, with a 2-week washout period. Dextromethorphan and dextrorphan were assayed by high-performance liquid chromatography. In the single-dose study, most metabolic ratios revealed good repeatabilities for the two periods (paired t test). The metabolic ratio from urine collected for 4 h, 6 h, 8 h or 12 h from plasma at any time between 1 h and 5 h or at 8 h, or from saliva at 2 h or 6 h, could reflect that from 0- to 24-h urine or AUCinfinity. In the multiple-dose study, all metabolic ratios revealed good repeatabilities. The plasma metabolic ratio at any time between 0.5 h and 10 h or the saliva metabolic ratio at any time between 3 h and 12 h, but not the urine metabolic ratio from any interval, could predict the metabolic ratio from ACUSStau. The 2 h, 3 h, 4 h or 5 h plasma metabolic ratio and 6 h saliva metabolic ratios after a single dose correlated significantly with their corresponding multiple-dose metabolic ratio (r > 0.8, P < .05). In conclusion, the plasma sample at 2 h, 3 h, 4 h or 5 h or the saliva sample at 6 h in either the single immediate-release (15 mg) or the multiple controlled-release dose (60 mg) procedure could be used for determining the dextromethorphan metabolic ratio.

The effect of aging on the pharmacokinetics of nalbuphine in rabbits

For the purpose of selecting an animal model for the study of the aging effect on the pharmacokinetics of nalbuphine, the pharmacokinetic properties in young and in aged rabbits were reported. Thirty-one healthy New Zealand white rabbits ranging in ages (mean) from three months to 43 months (six three months old, group I; nine eight months old, group II; nine 18 months old, group III; and seven 43 months old, group IV) were included in the study. After intravenous bolus injection of nalbuphine (10 mg kg-1) to each rabbit, plasma samples were collected and analysed for nalbuphine by a high-performance liquid chromatography method. The plasma concentration-time data regarding nalbuphine were successfully fitted to a linear two-compartment open model. The elimination half-life of nalbuphine in rabbits increased significantly with age. Consequently, clearance decreased significantly with age. The parameter AUCO-affinity, which is derived from dose/clearance, increased significantly with age. The effect of aging on the pharmacokinetics of nalbuphine in rabbits is quite similar to that in humans. From the present study, it is concluded that rabbits may be suitable for the study of aging effects on the pharmacokinetics of nalbuphine.

Determination of galactose in human blood by high-performance liquid chromatography: comparison with an enzymatic method and application to the pharmacokinetic study of galactose in patients with liver dysfunction

Galactose, the C-4 epimer of glucose, is an agent of choice for the quantitation of liver function. A simple, precise, and accurate high-performance liquid chromatographic (HPLC) assay with refractive index detection was developed for the determination of galactose in human whole blood. The method consists of organic solvent-heavy metal deproteinization procedures and reversed-phase chromatography on a cation-exchange column in the calcium form. Calibration graphs were linear over the concentration range 100-2500 microgram/mL, with correlation coefficients > 0.999. The within-day coefficient of variation (CV) ranged from 2.08 to 8.94%, and the between-day CV ranged from 1.61 to 10.9%. The limit of quantitation was 100 micrograms/mL in whole blood. However, the limit of detection was 75 micrograms/mL based on a signal-to-noise ratio of > or = 3. Eight structurally related sugars and polyols were investigated to check for potential interferences using the analytical condition of the assay. The possible metabolites of galactose present in the body were also checked to determine the specificity of this assay. The proposed HPLC assay was compared with an enzymatic assay and an excellent correlation was observed (HPLC = 1.0299Enz. - 12.907, r = 0.952, p < 0.001). This HPLC method has been successfully applied to the pharmacokinetic study of galactose in six patients with liver dysfunction. Following the intravenous administration of a dose of 0.5 g/kg body weight, galactose pharmacokinetics followed a nonlinear two-compartment model with Michaelis-Menten elimination from the central compartment.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of guaiphenesin in anti-tussive pharmaceutical preparations containing dextromethorphan by first- and second-derivative ultraviolet spectrophotometry

Rapid, simple and direct assay procedures based on selective first (D1)- and second (D2)-derivative spectrophotometry, using a zero-crossing technique of measurement at 279.2 and 280.0 nm, respectively, have been developed for the specific determination of guaiphenesin in the presence of dextromethorphan, drugs with closely overlapping absorption spectra, in synthetic admixtures and in pharmaceutical dosage forms (tablets and syrups). The methods do not require extraction with organic solvents and are easier to perform than their conventional counterparts. Calibration graphs were linear (r = 0.99999 for D1 and 0.99969 for D2, respectively). Good selectivity, accuracy and precision were found. However, the performance of the analysis of guaiphenesin by the second-derivative mode deteriorated when the ratio of dextromethorphan to guaiphenesin was greater than one. Thus, the first-derivative spectrophotometry is the method of choice for the assay of tablets and syrups containing the two drugs.