The intraocular dynamics of vancomycin hydrochloride ophthalmic ointment (TN-011) in rabbits

The intraocular dynamics of 1% vancomycin hydrochloride (VCM) ophthalmic ointment (TN-011) in rabbits was investigated. The animals used in the study were 42 pigmented rabbits with normal eyes (normal group) and 17 pigmented rabbits with Bacillus subtilis-infected eyes (BS group). The infection in the BS group was induced by a method previously established by the authors. Fifty milligrams of a 1% VCM ophthalmic ointment was administered into the cul-de-sacs of the animals' eyes unilaterally in both groups. Serum, bulbar conjunctiva (only from the normal group), cornea, iris-ciliary body, and vitreous were collected 15, 30, 60, 120, and 240 min after the drug administration as samples. Drug concentration was measured by the bioassay method. In the normal group, VCM in the bulbar conjunctiva reached a maximum concentration (98.98 ± 46.48 μg/g) at 30 min, and decreased to a level below the detection limit at 240 min. The maximum concentration of VCM in the cornea (12.04 ± 4.73 μg/g) was observed at 30 min. VCM was not detected in the aqueous humour, iris-ciliary body, vitreous, or serum in the normal group at any point. In the BS group, the maximum concentration of VCM was 25.60 ± 11.01 μg/g in the cornea 15 min after drug administration, and 5.18 ± 2.60 μg/ml in the aqueous humour at 30 min. VCM in the aqueous humor could be detected (0.37 ± 0.19 μg/ml) even after 240 min. VCM was not detected in the iris-ciliary body, vitreous, or serum at any point. The intraocular dynamics of 1% VCM ophthalmic ointment (TN-011) revealed that VCM reached the estimated effective concentrations in the aqueous humour as well as extraocular tissues of Bacillus subtilis-infected rabbit eyes. Received: August 8, 2002 / Accepted: November 18, 2002 Acknowledgments. The authors thank Toa Pharmaceutical Co., Ltd. for providing us with the VCM ophthalmic ointment, TN-011.     

Salivary duct carcinoma: A case report of oncocytic variant with possible treatment implications and review of literature

Salivary duct carcinoma (SDC) is an aggressive malignancy, resembling high-grade ductal carcinoma of the breast. Histologically, it shows cords and nests with cribriforming, marked nuclear atypia, comedonecrosis, perineural, and lymphovascular invasion. We report a rare case of SDC in a 61-year-old woman presenting with facial asymmetry, dysphagia, and cervical lymphadenopathy. Imaging showed an ill-defined infiltrating mass in parotid gland and multiple enlarged cervical lymph nodes. Histologically, the largest focus of tumor consisted of an intra-parotid lymph node replaced by sheets of bland appearing oncocytic tumor cells with abundant cytoplasm, centrally placed nucleus, and single prominent nucleolus. No mitotic figures were identified and focal areas showed nests with comedonecrosis and desmoplastic stromal response. Tumor showed strong positive staining for androgen receptor, CK7 and GATA-3. In addition, tumor stained strong positive for Her2neu making the patient amenable to Herceptin. NGS detected mutation in HRAS (p.Q61R) and a novel, not previously reported mutation in PIK3CA, (exon 21, p.H1047L). This case represents a rare presentation of SDC with bland cellular morphology unlike the usual associated high grade features. In addition, it reemphasizes the importance of androgen receptor in differential diagnosis from its mimics like oncocytic carcinoma and oncocytic variant of mucoepidermoid carcinoma. Further, Her2neu immunohistochemical status can be used for diagnosis as well as guide targeted therapy in these aggressive tumors.