Pharmacokinetics and biodistribution of paclitaxel-loaded microspheres

Paclitaxel(PTX)-loaded microspheres composed of poly(D,L-lactide-co-glycolide) (PLGA) were prepared by an O/W emulsion solvent evaporation method. This study was designed to investigate the preparation, in vitro release, in vivo pharmacokinetics and tissue distribution of a PTX-loaded microspheres system. Microspheres are characterized according to drug loading, size and shape. With a dynamic light scattering sizer and a transmission electron microscopy, it is shown that the PTX-loaded microspheres had a mean size of approximately 10.24 µm with narrow size distribution and a spherical shape. The in vitro release profiles indicate that the release of PTX from the microspheres exhibit a sustained release behavior. A similar phenomenon is observed in a pharmacokinetic study in rats, in which AUC of the microspheres formulation were 3.7-fold higher than that of PTX injection. The biodistribution study in mice showed that the PTX-loaded microspheres not only decreased drug uptake by liver, but also increased distribution of drug in lung. These results suggest that PTX-loaded microspheres may efficiently load, protect and retain PTX in both in vitro and in vivo environments, and could be a useful drug carrier for i. v. administration of PTX.

Different bladder defects reconstructed with bladder acellular matrix grafts in a rabbit model

OBJECTIVE

To evaluate the potential use of the bladder acellular matrix graft (BAMG), two different bladder defects in the rabbit model were reconstructed.

MATERIALS AND METHODS

Two groups of rabbits underwent partial bladder wall cystectomy (group A, 30-40%; group B, 70-60%) and reconstruction of the defects with an equally sized BAMG. After 4, 12, and 24 weeks, bladder cystographs were performed. Then the rabbits were killed after uneventful postoperative periods, and the grafts were harvested for H&E staining and immunohistochemical staining.

RESULTS

Two rabbits died on the postoperative days 3 and 6 in group A due to urinary peritonitis. At 24 weeks, in group A, the reconstructed bladders reached a mean volume of 94.39±0.54% of the precystectomy bladder capacity. Histologically, complete regeneration of smooth muscle and urothelium tissue was evident. Regenerated SMCs and urothelium stained positive for α-smooth muscle actin and AE1/AE3. In group B, the mean bladder volume was 64.5±3.19% of the precystectomy volume. Histologically, group B was characterized by multilayered urothelium without organized muscle tissue.

CONCLUSION

The BAMG was an effective scaffold for bladder wall regeneration in the rabbit model. However, the use of BAMG reconstruction in larger bladder defects did not induce the same quality and quantity of bladder regeneration as the reconstruction of smaller bladder defects.

Development and use of EST-SSR markers for assessing genetic diversity in the brown planthopper (Nilaparvata lugens Stål)

To assess genetic diversity in populations of the brown planthopper (Nilaparvata lugens Stål) (Homoptera: Delphacidae), we have developed and applied microsatellite, or simple sequence repeat (SSR), markers from expressed sequence tags (ESTs). We found that the brown planthopper clusters of ESTs were rich in SSRs with unique frequencies and distributions of SSR motifs. Three hundred and fifty-one EST-SSR markers were developed and yielded clear bands from samples of four brown planthopper populations. High cross-species transferability of these markers was detected in the closely related planthopper N. muiri. The newly developed EST-SSR markers provided sufficient resolution to distinguish within and among biotypes. Analyses based on SSR data revealed host resistance-based genetic differentiation among different brown planthopper populations; the genetic diversity of populations feeding on susceptible rice varieties was lower than that of populations feeding on resistant rice varieties. This is the first large-scale development of brown planthopper SSR markers, which will be useful for future molecular genetics and genomics studies of this serious agricultural pest.

104 BIRTH OF FIRST BUFFALO (BUBALUS BUBALS) CALF FOLLOWING EMBRYO SPLITTING AND POLYMERASE CHAIN REACTION SEXING AT BLASTOCYST STAGE

Embryo-splitting technology provides an effective procedure for increasing the number of transferable embryos per donor, producing genetically identical offspring and facilitating embryo sexing. The ability to identify the sex of embryos before transfer will offer a reliable, economical and practical procedure for buffalo breeding. In this study, we have assessed the feasibility of production of offspring with controlled sex in buffalo by first comparing the effect of blastocyst quality on the viability of demi-embryos and then identifying the sex of a demi-embryo by multiplex-nested PCR before transfer into the recipient. In vitro-matured buffalo oocytes were fertilized by IVF and cultured to the blastocyst stage for 6 to 7 days as described by Lu et al. (2007 Anim. Reprod. Sci. 100, 192–196). These blastocysts were classified in terms of their developmental pattern and morphology on a scale of 1 to 3 grades as described by McEvoy et al. (1990 Theriogenology 33, 1245–1253). Blastocysts were split into 2 equal parts by a micromanipulation system. Viability of the resulting demi-embryos was confirmed by formation of a blastocoel cavity and definite inner cell mass after culture for 24 h. One of the zone-free demi-embryos derived from a grade-1 blastocyst was cultured in TCM 199 supplemented with 10% fetal bovine serum for another 2 h, then was transplanted to a spontaneous oestrous recipient. The other demi-embryo was used for sexing by multiplex-nested PCR (Fu et al. 2007 Theriogenology 68, 1211–1218). The results showed that grade-1 blastocysts yielded more viable demi-embryos than grade-2 and grade-3 blastocysts [P < 0.01; 73/92 (79.67%) vs 32/76 (47.05%) vs 26/94 (26.53%), respectively]. Transplantation of the presumed-Y demi-embryo derived from grade-1 blastocyst into a recipient resulted in the birth of a male buffalo calf. To the best of our knowledge, this is the first buffalo calf produced following embryo splitting and PCR sexing of the embryo at the blastocyst stage. Successful birth of the desired-sex offspring in the present study indicates the feasibility of using embryo splitting in combination with multiplex-nested PCR sexing to produce offspring of controlled sex in swamp buffalo. However, the quality of embryos before splitting was an important factor governing the in vitro development of viable demi-embryos. This study was supported by the Guangxi Science and Technology R&D Program (0626001-3-1, 0815008-2-4).

Confined three-dimensional plasmon modes inside a ring-shaped nanocavity on a silver film imaged by cathodoluminescence microscopy

The confined modes of surface plasmon polaritons in boxing ring-shaped nanocavities have been investigated and imaged by using cathodoluminescence spectroscopy. The mode of the out-of-plane field components of surface plasmon polaritons dominates the experimental mode patterns, indicating that the electron beam locally excites the out-of-plane field component of surface plasmon polaritons. Quality factors can be directly acquired from the spectra induced by the ultrasmooth surface of the cavity and the high reflectivity of the silver (Ag) reflectors. Because of its three-dimensional confined characteristics and the omnidirectional reflectors, the nanocavity exhibits a small modal volume, small total volume, rich resonant modes, and flexibility in mode control.

The Treg/Th17 imbalance in patients with idiopathic dilated cardiomyopathy

To assess whether Treg/Th17 balance was broken in patients with idiopathic dilated cardiomyopathy (DCM). We studied 25 patients who were diagnosed as idiopathic DCM (18 men and seven women, mean age 35.6 +/- 5.2) and 25 normal persons (18 men and seven women, mean age 33.8 +/- 4.9). Then, we detected Treg/Th17 functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with idiopathic DCM and controls. The results demonstrated that patients with idiopathic DCM revealed significant increase in peripheral Th17 number, Th17-related cytokines (IL-17, IL-6, IL-23) and transcription factor (RORgammat) levels and obvious decrease in Treg number, Treg-related cytokines (TGF-beta1 and IL-10) and transcription factor (Foxp3) levels when compared to normal persons. Results indicated that Treg/Th17 functional imbalance existed in patients with idiopathic DCM, suggesting a potential role for Treg/Th17 imbalance in the development of idiopathic DCM.

Laparoscopic sacral colpopexy for uterine prolapse with prolene mesh

OBJECTIVE

To analyze the clinical effects of laparoscopic sacral colpopexy using prolene mesh for patients with pelvic organ prolapse.

METHODS

Laparoscopic placement of prolene mesh in the rectovaginal septum and veslcovaginal septum of 42 women with uterine prolapse with bladder and rectum prolapse. One mesh was fixed to the round ligaments and another to the periosteum of the sacral vertebrae. Operation time, blood loss, complication rate and follow-up surgery results were recorded monthly and analyzed according to the POP-Q system. The uterus was preserved in all cases.

RESULTS

The mean operating time was 92 +/- 12 min and the mean blood loss during surgery was 98 +/- 11 ml. Postoperatively, both prolapse and symptoms were highly significantly improved (p < 0.001) according to the pelvic organ prolapse quantification (POP-Q) system.

CONCLUSIONS

Laparoscopic sacral colpopexy for uterine prolapse using prolene mesh is a minimally invasive and effective new technique that offers a chance for patients who desire to preserve their uterus.

Photonic approach to the selective inactivation of viruses with a near-infrared subpicosecond fiber laser

We report a photonic approach for selective inactivation of viruses with a near-infrared subpicosecond laser. We demonstrate that this method can selectively inactivate viral particles ranging from nonpathogenic viruses such as the M13 bacteriophage and the tobacco mosaic virus to pathogenic viruses such as the human papillomavirus and the human immunodeficiency virus (HIV). At the same time, sensitive materials such as human Jurkat T cells, human red blood cells, and mouse dendritic cells remain unharmed. The laser technology targets the global mechanical properties of the viral protein shell, making it relatively insensitive to the local genetic mutation in the target viruses. As a result, the approach can inactivate both the wild and mutated strains of viruses. This intriguing advantage is particularly important in the treatment of diseases involving rapidly mutating viral species such as HIV. Our photonic approach could be used for the disinfection of viral pathogens in blood products and for the treatment of blood-borne viral diseases in the clinic.