The role of ultrasound in the detection of cervical lymph node metastases in clinically N0 squamous cell carcinoma of the head and neck.

Nodal involvement is the most important prognostic factor in head and neck squamous cell carcinoma (HNSCC) of mucosal origin. The presence of a single ipsilateral or contralateral metastatic node reduces survival by 50% and bilateral disease by a further 50%. The management of N+ HNSCC is relatively clear-cut. By contrast, the investigation and treatment of patients with clinically N0 disease is controversial. Most institutions electively treat the neck with surgery or radiotherapy because the risk of occult metastases is over 20%, even though it will be unnecessary in the majority of cases. In this situation the main purpose of staging would be to assess those nodes that are not going to be removed. However, the optimal management of the clinically N0 neck remains controversial and there is growing interest in a more conservative approach. Research is now directed toward finding a method of staging sensitive enough to bring the risk of occult metastases below 20%. High spatial resolution, ease of multiplanar scanning, power Doppler and the ability to perform guided fine-needle aspiration for cytology give ultrasound (US) an advantage over other imaging techniques.

Nerve ingrowth into diseased intervertebral disc in chronic back pain.

BACKGROUND: In the healthy back only the outer third of the annulus fibrosus of the intervertebral disc is innervated. Nerve ingrowth deeper into diseased intervertebral disc has been reported, but how common this feature is and whether it is associated with chronic pain are unknown. We examined nerve growth into the intervertebral disc in the pathogenesis of chronic low back pain. METHODS: We collected 46 samples of intervertebral discs from 38 patients during spinal fusion for chronic back pain. 30 samples were from pain levels clinically established by discography and 16 samples were from adjacent vertebral levels with no pain. We obtained 34 control samples of intervertebral disc from previously healthy individuals with normal histology within 8 h of recorded death. We used standard immunohistochemical techniques to test for a general nerve marker, a nociceptive neurotransmitter (substance P), and a protein expressed during axonogenesis (growth-associated protein 43 [GAP43]). FINDINGS: We identified nerve fibres in the outer third of the annulus fibrosus in 48 (60%) of the 80 samples of intervertebral discs. Nerves were restricted to the outer or middle third of the annulus fibrosus in the 34 control samples. Among the patients with chronic low back pain, nerves extended into the inner third of the annulus fibrosus and into the nucleus pulposus in 21 (46%) and ten (22%) samples, respectively. Nerves usually accompanied blood vessels, but in 14 of the samples from back-pain patients, isolated nerve fibres were seen in the discal matrix. Both types of nerve fibres expressed substance P, but only non-vessel-associated fibres expressed GAP43. Deep nerve ingrowth into the inner third of the annulus fibrosus, the nucleus pulposus, or both was seen in four (25%) of 16 biopsy samples from non-pain levels and in 17 (57%) samples from pain levels. Of the 16 paired samples from both pain and non-pain levels, five pain-level samples and one non-pain-level sample showed deep nerve ingrowth. INTERPRETATION: Our finding of isolated nerve fibres that express substance P deep within diseased intervertebral discs and their association with pain suggests an important role for nerve growth into the intervertebral disc in the pathogenesis of chronic low back pain.

Establishment and characterization of a subclone (U-937-AG) from a permanent human monocyte cell line.

The human cell line U-937 has many features suggestive of the monocyte. It may be stimulated in vitro to develop attributes of an activated macrophage with increased phagocytosis and enhanced Fc receptor expression. We describe the establishment of a subclone designated U-937 AG through the use of a mutagenic agent. The features of this subclone include increased tumoricidal cytotoxicity, increased Fc receptor expression for IgG and enhanced phagocytosis of antibody coated erythrocytes, while retaining the usual light microscopic features. The mutant cell line is also capable of producing an erythroid potentiating factor while temporary production of a granulocyte macrophage colony stimulating factor was noted. The availability of a "resting" parent and a more "activated" subclone of this human monocyte cell line should assist in the study of human monocyte activation.