Immunochemical techniques offer many advantages over chromatographic methods used for pesticide trace analysis of substrates such as soil, water, plants, urine, and blood. These advantages include speed of processing samples, high specificity for detecting a pesticide, reduced amount of preparation and cleanup of the sample before analysis, and a dramatic increase in the number of samples that can be analyzed. Immunoassays are based on the principle that antibodies to pesticides can be prepared, in animals, that can recognize and attach with exquisite specificity to certain chemical configurations displayed on the surface of a molecule. Small molecules such as herbicides usually are not immunogenic but can be made so by chemically bonding them to a large immunogenic protein such as bovine serum albumin before injection into an animal. Development of herbicide-specific antibodies and their use in direct and indirect enzyme-linked immunosorbent assays (EIA or ELISA) as well as radioimmunoassays (RIA) are discussed. The principles behind monoclonal antibody production are outlined, and immunoassays using polyclonal and monoclonal antibodies are compared. Specific reference is made to the development and use of indirect ELISA and RIA procedures for trace analysis of 2,4-D and picloram.

Granular cell tumour is a rare neoplasm that can occur in various sites. This report describes a 48-year-old female with a malignant granular cell tumour originating from the cervical sympathetic nerve trunk, who presented with hyperaesthesia of the left shoulder. The tumour had a maximum diameter of 86 mm and involved adjacent tissues directly.

Histopathologically, it showed considerable variation in the size and shape of nuclei, with occasional mitosis and an abundant granular cytoplasm. Immunohistochemically, the tumour reacted positively for S-100 protein and neuron-specific enolase, indicating its neural origin. Following total local excision of the lesion, the patient has been well without recurrence.

Primary paraganglioma of the external auditory canal is a rare otological finding. To date, only three cases have been reported in the world-wide literature. Such a tumour is now described in a 42-year-old female. The clinical and histopathological features of the case are discussed. The role of immunocytochemistry in defining diagnosis, from a large list of differentials, is illustrated. We present the first magnetic resonance images of this rare tumour and highlight the benefit of intra-operative frozen section in limiting surgery to canal excision.

A malignant course of juvenile laryngeal papillomatosis has rarely been reported. In the present case the patient had had laryngeal papillomas since the age of three years. The papillomas gradually spread to the entire respiratory system, and during 30 years the patient was operated on more than 80 times. At present an invasive tumour spreading from the tongue into the parapharyngeal space, extending to the cranial base, has been demonstrated by magnetic resonance imaging (MRI).

Intralesional therapy with Cidofovir, a promising antiviral drug against human papillomavirus (HPV) infection, was started with some clinical effect, although only on the superficial tumour growth. Histology of removed tumour tissue has demonstrated a mixture of exophytic and inverted growth pattern, and has mainly been interpreted as benign, in spite of a focally high mitotic index and an intermittent lack of maturation in the epithelium. In the most recent biopsies a verrucous carcinoma has been diagnosed. Expression of p53 was noted to increase in papillomas with time. All samples have been shown to harbour HPV 11, but no other HPV types.

Hypopharyngeal carcinoma (HPC) has a poor prognosis. We investigated the expression of cyclin D1 in 34 advanced HPCs, and the value of cyclin D1 expression was evaluated as a predictive marker in terms of the prognosis of HPC, compared with other clinical factors. Using immunohistochemical staining, 20 of 34 patients showed positive immunoreactivity for cyclin D1. The statistical trend of the survival rate was lower in the cyclin Di-positive patients than in the cyclin D-negative ones (p = 0.0805). The predictive factors for the survival rate were effectiveness of neo-adjuvant chemotherapy (F = 8.698) (p = 0.0066), cyclin D1 expression (F = 6.244) (p = 0.0191) and N classification (F = 5.037) (p = 0.0335). The cyclin D1-positive patients had approximately four-fold higher mortality than the cyclin D1-negative ones. These data indicate that the expression of cyclin D1 in advanced patients with hypopharyngeal carcinoma is a useful marker for prognosis.