Morphology of the digestive system of the lesser bamboo rat (Cannomys badius).

The lesser bamboo rat is a fossorial rodent within the monotypic genus Cannomys, family Spalacidae and is found in Indochina. The present work provides the first detailed description of the morphology of its digestive system, as examined by gross dissection and histological examination. The oesophagus was lined by a heavily keratinized epithelium and contained mostly striated muscles in the muscularis externa. The stomach was of the unilocular-hemiglandular type with a cornified squamous area at the fundus separated from the glandular area by the limiting ridge. The length ratio of the small intestine to the entire intestine was relatively low compared to that in other rodents. The caecum contained five to seven haustra and numerous lymphoid tissues, but no distinct appendix. Within the long colon, two non-papillated longitudinal folds forming a colonic groove, V-shaped mucosal folds like fishbones and abundant goblet cells were apparent. A five-lobed liver with a gallbladder and a diffuse pancreas were evident. These findings may indicate that the lesser bamboo rat is a caecal fermenter capable of feeding on highly abrasive plant material. Fermentation may take place via a mucus-trap colonic separation mechanism without coprophagy. The digestive system of the lesser bamboo rat is somewhat different from that of spalacid relatives.

Morphological characteristics of the tongue and lingual papillae of the large bamboo rat (Rhizomys sumatrensis).

The large bamboo rat (Rhizomys sumatrensis) is a fossorial rodent found throughout Indochina that has a distinct habitat dominated by bamboo thickets. In the study reported here, the lingual biology of this rodent is described in detail, based on characteristic features of the tongue and lingual papillae as determined by light and scanning electron microscopy studies. The tongue was found to be elongated with a rounded apex and possessed a median groove and a well-developed intermolar prominence. Three types of the papillae were found on the dorsal lingual surface: filiform, fungiform and vallate papillae. The most abundant papillae were the filiform papillae, the majority of which had a wide base and fork-like processes. Rounded fungiform papillae with one to four taste buds were randomly distributed among the filiform papillae, with a high density found at the anterior tongue, particularly the apex. Two oval vallate papillae were observed on the posterior part of the tongue, surrounded by a circumferential groove into which their numerous gustatory pores opened. The lingual radix had no papillae but contained mucus-secreting Weber's salivary glands. Structural adaptations of the tongue to meet the functional demands of food ingestion and food manipulation in the oral cavity are also discussed.

Effect of a thiolated polymer on oral paclitaxel absorption and tumor growth in rats.

The anticancer agent paclitaxel is currently commercially available only as an infusion due to its low oral bioavailability. An oral formulation would be highly beneficial for patients. Besides the low solubility, the main reason for the limited oral bioavailability of paclitaxel is that it is a substrate of the efflux pump P-glycoprotein (P-gp). Recently, it has been demonstrated that P-gp can be inhibited by thiolated polymers. In this study, an oral paclitaxel formulation based on thiolated polycarbophil was evaluated in vivo in wild-type rats and in mammary cancer-induced rats. The paclitaxel plasma level after a single administration of paclitaxel was observed for 12 h in healthy rats. Moreover, cancer-induced rats were treated weekly for 5 weeks with the novel formulation. It was demonstrated that (1) co-administration of thiolated polycarbophil significantly improved paclitaxel plasma levels, (2) a more constant pharmacokinetic profile could be achieved and (3) the tumor growth was reduced. These effects can most likely be attributed to P-gp inhibition. According to the achieved results, thiolated polymers are believed to be interesting tools for the delivery of P-gp substrates such as paclitaxel.

Neurovascular anatomy of the penis and pelvis in Thai males: applications to male-to-female and pelvic surgeries.

OBJECTIVE: To determine the neurovascular profiles in the pelvis and penis for applying to sex reassignment surgery. MATERIAL AND METHOD: Dissection of the pelvis and penile shaft was performed in 12 soft-preserved and 32 fresh adult male cadavers respectively. The neurovascular structures were located and documented, and the distances between anatomical landmarks were measured. Thirty-two specimens from the glans penis were obtained for immunohistochemical analysis to analyze its innervation and blood supply. RESULTS: Several anatomical variations of penile arterial supply were found. They are the presence of the accessory pudendal artery, multiple cavernous and bulbourethral arteries. The unilateral dorsal artery was observed in 10 of 32 cadavers, predominantly on the left. From the root to the neck of the penis, the dorsal nerves were divided into two groups. The first group of fibers innervating the glans coursed along the dorsolateral surface of the shaft and pierced the entire area of the corona. The other group diverged to distribute throughout the lateral surface to innervate the lateral and ventral portions. The mean distance between the left and right medial main branches that terminated in the glans was 1.18 cm. Immunohistochemical analysis revealed that the main nerves, after entering the glans, divided into terminal branches that concentrated around urethra. A mean distance from the main nerves to the epithelium was 0.71 cm. CONCLUSION: This detailed anatomy in the pelvis and along the penis should provide a valuable guide for sex reassignment surgery and intrapelvic operations.