In vitroandin vivostudies of ibuprofen-loaded biodegradable alginate beads

The irritation effects of ibuprofen, a widely used non-steroidal anti-inflammatory drug (NSAID), were evaluated on mouse gastric and duodenal mucosa when suspended in 0.5% (w/v) sodiumcarboxymethylcellulose (NaCMC) solution and loaded in alginate beads. The ionotropic gelation method was used to prepare controlled release alginate beads of ibuprofen. The influence of various formulation factors on the encapsulation efficiency, as in vitro drug release and micromeritic properties, was investigated. Other variables included the alginate concentration, percentage drug loading and stirring speed during the microencapsulation process. Scanning electron micrographs of alginate beads loaded with ibuprofen showed rough surface morphology and particle sizes in the range of 1.15 +/- 0.4 - 3.15 +/- 0.6 mm. The yield of microspheres, as collected after drying, was generally 80-90%. Formulation code H showing t50% value of 3.5 h was chosen for in vivo trials because of the appropriate drug release properties. For in vivo trials, free ibuprofen (100 mg kg(-1)), blank and ibuprofen (100 mg kg(-1)) loaded alginate beads (formulation code H) were suspended in 0.5% (w/v) NaCMC solution and each group was given to six mice orally by gavage. NaCMC solution was used as a control in experimental studies. In vivo data showed that the administration of ibuprofen in alginate beads prevented the gastric lesions.

Myogenesis within the human gubernaculum: histological and immunohistochemical evaluation

BACKGROUND

The presence of varying amounts of smooth muscle (SM) in the patent processus vaginalis suggests that SM plays a role in the descent of the testis. Myogenesis within the gubernaculum (representing primitive mesenchymal tissue) has been evaluated.

MATERIALS AND METHODS

Bilateral gubernacula of ten male and five female fetuses were obtained. Sections were stained with hematoxylin-eosin, van Gieson and Gomori trichrome. Expressions of human muscle actin, desmin, vimentin, alpha-smooth muscle actin, human myosin, fast myosin, slow myosin, and Myo-D were determined through immunohistochemistry. The structural alterations and expressions according to the fetal ages were determined within the gubernacula of both sexes.

RESULTS

Gubernacula revealed striated muscle at twelve weeks of age. Despite expression of actin and desmin, those muscles did not express Myo-D. Actin and desmin expressing striated muscles ceased to exist until 22 weeks of age. Both vascular SM and cremaster muscle (CM) expressed Myo-D during the 22nd and 23rd weeks. CM additionally expressed alpha-smooth muscle actin. Detection of myofibroblasts in the 22nd week was followed by appearance of the SM in the 27th week in the gubernacula of male fetuses. The same alterations were encountered among the female fetuses at later time points.

CONCLUSION

Both smooth muscle and CM develop within the gubernaculum. CM may have transdifferentiated from the vascular SM. If the gubernaculum represents primitive mesenchymal tissue, it ceases to exist after the development of muscles.

Early cirrhosis in a patient with type I citrullinaemia (CTLN1)

A 17-month-old girl with type I classical citrullinaemia (CTLN1) presenting with early cirrhosis and unusual ultrastructural features of the liver is reported. The patient is homozygous for a splicing mutation in intron 15 of the argininosuccinate synthase gene.

Apoptosis in the developing human brain: a preliminary study of the frontal region

BACKGROUND

Natural cell death due to apoptotic mechanisms has been described in various species. Relatively few studies examined this process in humans.

AIM

To investigate the distribution of apoptosis in fetal brain tissue.

DESIGN

We examined apoptosis in the frontal region of human fetal brain by the TUNEL method in nine fetuses with no neurological conditions, gestational age 14-26 weeks, and three fetuses with structural anomalies of the nervous system (lumbar meningomyeloceles, n=2, hydrocephalus, n=1).

RESULTS

In normal fetuses, TUNEL-positive cells were most concentrated in the intermediate zone (IZ) and between 18 and 22 weeks of gestation; cortical apoptosis was not prominent. The fetus with hydrocephalus had increased numbers of TUNEL-positive cells while those with neural tube defects did not differ from normals.

CONCLUSION

The definition of normally occurring apoptosis may provide a basis for further studies directed at central nervous system (CNS) malformations.

Short term human primary pulpal response after direct pulp capping with fourth-generation dentin adhesives

The purpose of this study was to evaluate the effects of the total-etch and direct pulp capping techniques on the short-term response of mechanically exposed human primary tooth pulps using three commercially available adhesive resin systems. Class V cavities were prepared on the buccal surface of intact mandibular primary molars and exposed with a carbide bur on the cavity floor. The entire cavity except the exposure site received 36% phosphoric acid gel conditioning. Exposed pulps were capped with one of the three adhesive resins, followed by restoration of the cavities with the respective restorative materials. The teeth were extracted after 60 days and prepared according to normal histological techniques. Serial sections were stained with H/B for histological evaluations. The histopathological evaluation showed that a few of the samples in the Scotchbond Multi Purpose (SMP) and Prime & Bond 2.1 (PB) groups exhibited "attempted bridge formation", while no bridge formation was evident in the other samples. Syntac Single Component (Syntac) exhibited the most severe histological response, while the mildest reactions were observed in the SMIP group. Based on the conditions of the present study, direct pulp capping with dentin bonding agents following the total-etch technique in primary teeth can not be recommended.

Transient intrauterine hypotension: effect on newborn rat brain

Intrauterine perfusion failure can cause cerebral malformations. We investigated the effect of transient maternal hypotension on newborn rat brain by inducing hypovolemic hypotension for 2.5 h during early embryonic day 7 (E7) or late (E15) gestation in pregnant rats. We found an increase in the number of TUNEL-positive cells within the periventricular germinative matrix in pups subjected to early gestational hypotension and within the cerebral cortex in those subjected to late gestational hypotension in comparison to sham control animals. These results suggest that episodic maternal hypovolemic hypotension may affect the fetal brain, and apoptotic mechanisms may mediate this effect.

Light and electron microscopic examination of exocrine pancreas using zinc iodide-osmium tetroxide technique

Zinc iodide-osmium tetroxide (ZIO) fixation/staining technique is a metallophilic technique which has been used for the examination of various tissues and cell types. We examined the ZIO (+) cell types in rat exocrine pancreas to obtain further evidence for the significance of the reaction. Among mostly non-reactive pancreatic acinar cells there were ZIO (+) acinar cells of varying staining intensity. Zymogenic granules and centroacinar cells were completely non-reactive. Our electron microscopic findings support the view that the reactivity of the technique used is cell specific but not cell type or organelle specific.