Stabilization of labile active ingredients in an oil-water emulsion cosmetics by freeze-drying

BACKGROUND

Due to the instability in oil/water emulsion, certain labile active ingredients were often not used in cosmetics.

OBJECTIVE

The present study has tested the effect of freeze-drying to stabilize an oil/water cosmetic emulsion.

MATERIALS AND METHODS

A preliminary freeze-drying process was established at the basis of calorimetric and freeze-drying microscope studies. The stability of labile molecules in the cosmetic emulsion was evaluated at 48 degree C after freeze-drying.

RESULTS

The accelerated stability experiment showed that the freeze-dried emulsion retained 90.1% vitamin C after 28 days at 48 degree C, whereas the oil-water emulsion retained only 28.3% vitamin C. The freeze-dried emulsion had significantly less oil oxidation than did the oil-water emulsion.

CONCLUSION

Freeze-drying improved the stability of vitamin C and oily active ingredients in cosmetic emulsions. DOI: 10.54680/fr23210110312.

Activation of p38MAPK in spinal microglia contributes to autologous nucleus pulposus-induced mechanical hyperalgesia in a modified rat model of lumbar disk herniation

Recent studies have implicated the activation of p38 mitogen-activated protein kinase (MAPK) and glial cells contribute to hyperalgesia following nerve injury or nerve compression. In our work, we investigated the underlying mechanisms of autologous nucleus pulposus (NP)-induced mechanical hyperalgesia in a modified rat model of lumbar disk herniation (LDH). Firstly, our results showed that 50% mechanical withdrawal threshold (50% MWT) decreased on postoperative day (POD) 1 and significantly minimally reduced on POD 7 and lasted for day 28 after surgery (P < 0.05). Secondly, phosphorylation of p38MAPK (p-p38MAPK) and glial cells were monitored on POD 1, 3, 7, 14 and 28 using immunofluorescence staining. P38MAPK activation, observed in the spinal cord, began to increase on POD 1, peaked on POD 3, and significantly decreased on POD 14 and POD 28 (P < 0.05). Microglia activation was initiated at day 1, maximal at day 3, and maintained until day 14 after surgery (P < 0.05). Astrocytic activation was found in 7 to 14 days after modelling (P < 0.05). Then, double immunostaining method was applied to observe the co-expression of p-p38MAPK and glial cells, and it showed that p-p38MAPK was mainly expressed in activated microglia, rarely in neurons, and none in astrocytes. Lastly, we discovered that both SB203580 (50ug, p38MAPK inhibitor) and minocycline (0.5 mg, microglial inhibitor) would inhibit the p-p38MAPK protein expression tested by western blot analysis and reduce mechanical hyperalgesia. In conclusion, current study suggest that activation or phosphorylation of p38MAPK in spinal microglia contributes to autologous NP-induced mechanical hyperalgesia in our animal model.

Huge nasopharyngeal angiofibroma with intracranial extension: change in the dura mater and choice of surgical management

We aimed to review (1) the imaging changes in the dura mater in cases of huge, lobulated juvenile nasopharyngeal angiofibroma, and (2) the choice of surgical management.

Imaging from four cases of juvenile nasopharyngeal angiofibroma showed extrapharyngeal extension of the tumour. The sphenoid sinus, sella turcica and clivus were extensively eroded, and the tumour had spread deep into the cranial fossa. In three cases, intracranial exploration was performed to treat the intracranial tumour lobule. Subsequently, the tumours were removed using extracranial approaches. No perforation of the dura mater was found in these three cases, although the dura mater in the superior orbital fissure was congested, haemorrhagic and solid. Pre-operative imaging for two cases (i.e. the first operation for one and the second operation for the other) revealed no dura mater perforation. A transantral approach via a midfacial degloving incision was used to remove these tumours completely.

We conclude that change in the dura mater is a crucial indication for the choice of management. If the dura mater is intact, a transantral approach via a midfacial degloving incision may remove the tumour successfully.

[The preoperative application of selective catheterization and embolism of the external carotid artery in treating tumors with enriched blood supply in the base of skull]

OBJECTIVE

Embolizing the feeding vessels of the tumors with enriched blood supply in the base of skull in order to reduce the bleeding during operation.

METHOD

Under digital subtraction angiographic control, superselectively catheterizing the external carotid artery, thus occluding the terminal branches of the feeding arteries of the tumor with particles of liquidized gelfoam.

RESULT

Nine cases studied showed that the angiography of the feeding vessels of the tumor disappeared relatively. The bleeding decreased significantly during operation. The postoperative pathological findings showed that the entity of the tumor was congested with gelfoam.

CONCLUSION

After figuring out the blood supply of the tumor, superselective catheterization of the external carotid artery followed by occlusion of the feeding vessels can reduce the size of the tumor and diminish the bleeding during operation, thus can improve the safety of the operation. It should be one of the crucial preoperation measures.

The role and significance of chondroitin sulfate in the development of otosclerosis

Chondroitin sulfate is a sulfated glycosaminoglycan that predominates in the ground substance of cartilage. Using monoclonal antichondroitin sulfate in 61 specimens of human otosclerotic lesions, we studied the distribution of this glucosaminoglycan in various stages of otosclerosis. Our findings show that chondroitin sulfate plays an important role in the development of otosclerosis. In addition, the distribution of chondroitin sulfate clearly delineates the stage of otosclerosis referred to as active into two distinct histologic stages. Dividing the active stage into "osteolytic" and "sponge-chondroid" would be reasonable based on our findings.

Significance of chondrification in the development of otosclerotic stapedial footplate

Thirty-four otosclerotic stapes of active type were investigated histologically with hematoxylin-eosin (H-E), periodic acid-Schiff-alcine blue (PAS-AB), and/or toluidine blue stain. The results show that chondrification plays an important role in the development of otosclerosis. To date, this specific histopathologic change has not been well recognized. Based on the findings of this study, it is suggested that the active type of otosclerosis be subdivided into two phases, the osteolytic phase and spongy chondroid phase.

A morphometric study of the effects of pressure on bone resorption in the middle ear of rats

Bone destruction is one of the clinical features of chronic otitis media with cholesteatoma. Bone resorption may be due to the epithelial debris accumulated in the cholesteatoma epidermal sac that acts as foreign body material inducing a destructive granulation tissue and creates pressure on the bony middle ear. This compressive force then induces bone resorption. The present study was designed to replicate certain conditions similar to those in cholesteatoma leading to bone resorption. Four types of materials were implanted into the middle ear cavity of rats: (1) laminaria, an expandable seaweed material, (2) preswollen laminaria, (3) keratin powder suspension, and (4) surgical grade silicone, which when bent exerts pressure on the bulla wall. The placement of laminaria segments in the middle ear cavity of rats was followed by swelling of the implanted materials within 7 days. The bulla bone response was by neo-osteogenesis as well as active bone resorption. The new bone was observed on the external and/or internal surface of the tympanic bone. The cochlear bone also showed extensive bone resorption in the animals. Osteogenesis was rarely observed on the capsule of the cochlea. We also observed no bone resorption at sites without presence of inflammatory connective tissue between laminaria and bone. The typical multinucleated osteoclasts were often seen at the resorption area but the majority of bone resorption sites were characterized by the presence of mononuclear cells and other inflammatory cells. Preswollen laminaria, keratin powder, and silicone strips induced minimal bone resorption. No resorption was observed in the bony cochleas of these experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of granulation tissue conditioned medium on the in vitro differentiation of keratinocytes

The accumulation of desquamated keratinizing squamous epithelial cells appears to be a crucial factor in the pathogenesis of middle ear cholesteatomas. The accumulation of keratin debris is due to the proliferation and the terminal differentiation of basal keratinocytes. Since cholesteatomas are usually associated with inflammatory reactions in the middle ear cavity, we examined the effects of a granulation tissue conditioned medium on the terminal differentiation of basal keratinocytes in vitro. This conditioned medium stimulated the terminal differentiation of basal keratinocytes by showing: (a) increased incorporation of 3H-leucine into cell envelopes; (b) an increased number of SDS-insoluble cell envelopes; and (c) increased transglutaminase activity (as a marker for terminal cellular differentiation). Our present studies further suggest that inflammatory granulation tissue plays an important role in the clinical growth and development of the cholesteatoma.

Experimental induction of middle ear cholesteatoma in rats

We induced cholesteatoma in two groups of rats by instilling different concentrations of propylene glycol into the middle ear cavity. Fifteen rats were exposed to 50% propylene glycol (group I), while pure propylene glycol was applied to six others (group II). The group I rats were killed 1 month after instillation. Seven of the 15 showed cholesteatoma in the middle ear with accumulation of keratin debris. The group II rats were killed 3 months after instillation. All six animals showed inflammation in the experimental ears, and five of the six experimental ears showed cholesteatoma in the middle ear cavity. Six experimental ears in group I and five in group II revealed retraction of the tympanic membrane, possibly due to eustachian tube obstruction. Bone resorption was seen along with cholesteatoma and inflammatory cells and osteoclasts in the middle ear of all 11 of these rats. The seventh cholesteatoma of group I can be classified as a microcholesteatoma, a pearl-like cyst within the tympanic membrane. The microcholesteatoma was formed by an invasion of basal cells from the tympanic epidermis and the proliferation of these cells in the fibrous layer of the tympanic membrane. Our findings suggest that cholesteatoma in the middle ear cavity is a response to the inflammation produced by high concentrations of propyleme glycol.

Age-related epithelial migration on the tympanic membrane of the Mongolian gerbil

Epithelial migration on the tympanic membrane of young and aged gerbils was studied; Sudan black B was used as a marker dye. The epithelial migration center was found at the region of umbo, manubrium, and the short process of the malleus. The epithelial migration rates of the gerbils aged 3 to 6 months, 9 to 12 months, and 24 to 30 months were approximately 116, 113, and 86 micron per day, respectively. These findings suggest that the low epithelial migration rate on the tympanic membrane and external ear canal might play an important role on the high occurrence rate of external ear keratosis that results from accumulation of keratin debris in the aged gerbil ears.

Type II collagen-induced otospongiosis-like lesions in rats

Otospongiosis-like lesions were induced in rats by immunizing them with type II collagen. After seven months' immunization, the rats were killed and processed for histologic study. We found otospongiotic lesions in the bony cochlea, vestibule, semicircular canal, and in the regions near the oval window and round window. The spongiotic lesions in the otic capsules were similar to human otospongiosis and were characterized by the following types of microscopic appearances. 1) The classic type showed enlarged vascular spaces with congestion, macrophages, fibroblasts, and sometimes osteoclasts. 2) The fibrotic type showed vascular spaces filled with fibrous tissues. 3) The osteoporotic type had a porous appearance and was devoid of content. 4) The sclerotic type showed bone spaces partially or entirely being replaced by new bone with blue mantles and a mosaic appearance. Some spongiotic lesions showed a mixture of the above types. The findings suggest that this animal model may provide important information to help understand the process of human otosclerosis.