New histochemical and ultrastructural observations on normal bovine tonsils

Samples of normal bovine palatine tonsils were examined by light and electron microscopy. Like human tonsils, they were composed of crypts, subepithelial areas, follicles, and T-dependent zones, but their well-developed capsule subdivided the lymphoid tissue by connective septa. B cells formed the major lymphoid component. The follicles and T-dependent zones had morphological and histochemical features typical of peripheral lymph organs. Follicular dendritic cells were isolated and shown to be similar to human follicular dendritic cells.

Sentinel lymph node biopsy for conjunctival melanoma

OBJECTIVE

To investigate the feasibility and safety of preoperative lymphoscintigraphy and sentinel lymph node (SLN) biopsy for conjunctival melanoma.

METHODS

A 49-year-old man with a biopsy-proven malignant melanoma of the conjunctiva (caruncle) underwent preoperative lymphoscintigraphy and SLN biopsy using a technique in which both isosulfan blue dye and technetium Tc 99 m sulfur colloid were injected in the subconjunctival space around the primary lesion. The conjunctival melanoma was excised just before identification and removal of the SLNs. The SLNs were excised along with concomitant dissection of their associated lymph node basins. The SLNs were evaluated histologically using serial sectioning and immunohistochemical staining with antisera against the S-100 protein and the melanoma antigen HMB-45.

RESULTS

Three SLNs were identified in the left submandibular and the left upper and middle jugular lymph node basins during the preoperative lymphoscintigraphy. The same three SLNs were successfully identified in the operating room. The SLNs were histologically negative, and the immunohistochemical staining against S-100 and HMB-45 was also negative. We did not observe any immediate adverse effects on the globe or the periocular structures from lymphatic mapping and SLN biopsy. By 24 hours after injection of blue dye, only a faint trace of blue was visible on the ocular surface.

CONCLUSIONS

Preoperative lymphoscintigraphy and SLN biopsy can be performed safely in patients with conjunctival melanoma. A larger study is planned to determine the sensitivity of this technique for the detection of occult regional nodal disease in patients with conjunctival melanoma.

Prognostic factors for survival in malignant melanoma of the eyelid skin

PURPOSE

This study aimed to determine the prognostic factors for survival and disease-free interval for malignant melanoma of the eyelid skin.

METHODS

This was a retrospective, nonrandomized, clinical review. Twenty-four patients with eyelid skin melanoma were identified through a search of the tumor registry at M. D. Anderson Cancer Center. Patients were treated between 1953 and 1994. The follow-up ranged from 3 to 18 years (mean = 9.6 years). Primary treatment in all cases entailed wide local excision of the tumor. Patients in whom regional lymph node metastasis developed underwent parotidectomy or neck dissection, with or without adjuvant chemotherapy or external beam radiation. Descriptive statistics were used to characterize the patients. Survival analysis in terms of disease-free survival and recurrence-free survival was performed using age, sex, location of tumor (upper lid, lower lid, or both), histologic type of melanoma, Breslow thickness, and Clark's level as independent variables for survival.

RESULTS

Age, sex, location, and the histologic type of tumor were not significant prognostic indicators for survival in this cohort. Clark's level > or = IV by itself was a statistically significant predictor of decreased survival. In addition, tumors with either Clark's level > or = IV or Breslow thickness > or = 1.5 mm were associated with increased mortality.

CONCLUSION

Clark's level > or = IV or Breslow thickness > or = 1.5 mm are poor prognostic indicators for malignant melanomas of the eyelid skin. Clinicians should have a high level of suspicion for occult regional lymph node metastasis when treating patients with these tumor features.

Porcine myelomonocytic markers: summary of the Second International Swine CD Workshop

Forty five mAbs submitted to the Second International Swine CD workshop were analyzed by six different laboratories for their possible reactivity with porcine myelomonocytic cells using flow cytometry and immunohistochemistry. As a result of these analyses, a new swine workshop cluster, SWC9, composed of two mAbs that recognize an antigen selectively expressed on mature macrophages, was defined. In addition, several mAbs were identified, allowing the differentiation of granulocytes from monocytes/macrophages, or monocytes from macrophages. Further work is required to identify the antigen recognized by these mAbs. Nevertheless, they should already prove useful for the identification of different stages in the macrophage maturation/differentiation, and will certainly aid analyses on the complexity of the mononuclear phagocyte system in the pig. Finally, the cross-reactivity of three anti-human CD14 mAbs with porcine myelomonocytic cells was established in this workshop.

Workshop studies with monoclonal antibodies identifying a novel porcine differentiation antigen, SWC9

Two monoclonal antibodies (mAb) within cluster M4 of the myeloid section of the Second International Swine CD Workshop, C4 (No. 144) and PM18-7 (No. 192), showed reactivity with thymocytes and among cells of myelomonocytic origin with mature macrophages but not with monocytes and granulocytes. Both mAb recognize a protein showing two bands of 205 kDa and 130 kDa under both reducing and non-reducing conditions. Although epitope mapping with these mAb could not be performed, this cluster received the SWC9 designation.

Transduction of normal and malignant oral epithelium by an adenovirus vector: the effect of dose and treatment time on transduction efficiency and tissue penetration

We tested an adenovirus vector that carries a beta-D-galactosidase marker gene for its ability to transduce normal oral mucosa and oral carcinoma cells. Topical application of adenovirus to normal oral mucosa of mice at 1 x 10(10) plaque-forming units (pfu)/mL for 1 minute did not result in transduction of epithelial cells. Similarly, topical application to human oral mucosa ex vivo was not successful. However, systemic administration by intracardiac injection of hamsters did transduce normal oral mucosa effectively. To evaluate transduction of carcinomas, the Tu138 human oral cancer cell line was used. A single application of virus at 1 x 10(8) pfu/mL in vitro resulted in 30% of oral carcinoma cells expressing the marker gene, and 2 x 10(8) pfu/mL transduced 60% of cells. After two applications of virus at 2 x 10(8) pfu/mL with an interval of 18 hours, 100% of oral carcinoma cells expressed the marker gene. Topical application to a raft culture of Tu138 cells for 1 hour produced gene expression that penetrated up to four layers of cells. To emulate the effect of treating a carcinoma, Tu138 cells were implanted subcutaneously in nude mice, allowed to grow to a tumor 1 cm in diameter, and then injected directly with virus. This produced diffuse transduction of around 30% of cells in the tumor, and expression was seen in cells at a significant distance from the injection site. Adenovirus vectors are therefore capable of transferring novel genetic information to both normal and malignant oral mucosa. They may have potential for use in gene therapy in the prevention or treatment of oral squamous carcinomas.