Role of salivary epidermal growth factor in the pathogenesis of Barrett's columnar lined oesophagus.

Epidermal growth factor (EGF) is implicated in the regeneration of epithelial cells at the site of inflammation or ulceration in the gastrointestinal tract. Single parotid EGF concentration and production was studied in 64 patients with Barrett's columnar lined oesophagus (CLO), in 22 patients with severe reflux oesophagitis without columnar metaplasia and in 51 normal controls. In control patients, mean salivary EGF concentration was 2790 pg/ml (median 1450 pg/ml; range 450-16,500 pg/ml) and mean single parotid EGF production was 2550 pg/min (median 1750 pg/min; range 790-18,000 pg/min). Patients with severe reflux oesophagitis had a similar EGF concentration (mean 3112 pg/ml; median 1500 pg/ml; range 300-16,000 pg/ml) and production (mean 3100 pg/min; median 2200 pg/min; range 790-17,950 pg/min) to controls. Patients with CLO had a 62 per cent lower mean EGF concentration (mean 1197 pg/ml; median 640 pg/ml; range 233-4500 pg/ml) (P less than 0.001, Mann-Whitney U test) and a 60 per cent lower EGF production (mean 1254 pg/min; median 800 pg/min; range 170-3125 pg/min) (P less than 0.001, Mann-Whitney U test) than patients with severe reflux oesophagitis. A subpopulation with malignant change in CLO (n = 16) had a similar EGF concentration and production to the CLO group as a whole (mean 1240 and 1300 pg/min, respectively). Low salivary EGF levels are associated with Barrett's CLO but not with severe oesophagitis without columnar metaplasia. EGF levels do not identify those patients who will subsequently develop malignant change.     

Experimental induction of urothelial metaplasia

An experimental model has been designed to produce a situation similar to bladder exstrophy in rats. Sequential study of the exposed bladder demonstrated the induction of metaplastic changes leading to cystitis glandularis. The model appears well suited for evaluation of urothelial responsiveness to mechanical and chemical agents.     

High oesophageal stricture with hiatal hernia and a lower oesophagus lined by columnar epithelium

A 23-year-old man with a six months' history of dysphagia was found to have hiatus hernia with reflux and a stricture of the mid-oesophagus. Death from unrelated causes permitted detailed histological examination. This showed a high squamo-columnar junction with ulceration confined to the squamous epithelium immediately above the junction. The columnar epithelium of the lower oesophagus was largely of cardiac type, but a few gastric body type glands were present at the lowermost end. This mixed pattern and the complete lack of inflammation or fibrosis beneath the columnar epithelium favours a congenital rather than metaplastic origin. A high squamo-columnar junction is of clinical significance only in the presence of reflux when oesophagitis and stricture develop at an unusually high level.     

Intestinal metaplasia in patients with columnar lined esophagus is associated with high levels of duodenogastroesophageal reflux

OBJECTIVE: To evaluate the rate of duodenogastroesophageal reflux in patients with columnar lined esophagus compared with patients with gastroesophageal reflux disease without columnar lined esophagus, and to analyze whether it is related to the presence of specialized columnar epithelium in the metaplastic segment. SUMMARY BACKGROUND DATA: The carcinomatous degeneration of columnar lined esophagus originates from a specialized columnar epithelium. The appearance of this metaplastic phenomenon is clearly related to severe prolonged gastroesophageal reflux, but only some of these patients finally develop columnar lined esophagus. For this reason other factors have been suggested, particularly the role played by the reflux of duodenal contents into the esophagus. METHODS: The authors studied 15 healthy volunteers (control group), 10 patients with reflux symptoms but without endoscopic lesions, 20 patients with reflux esophagitis without columnar lined esophagus, and 35 patients with columnar lined esophagus (complicated with ulcers or stenosis in 8 cases), of whom 22 had intestinal metaplasia. To assess the reflux of duodenal contents into the esophagus, all the patients underwent Bilitec 2000 and 24-hour esophageal pH monitoring. RESULTS: The presence of bilirubin in the material refluxed into the esophagus was greater in the patients with columnar lined esophagus than in the rest of the groups. Likewise, duodenogastroesophageal reflux was greater in the columnar lined esophagus patients who had intestinal metaplasia. CONCLUSIONS: Duodenogastroesophageal reflux may play a major role in the development of columnar lined esophagus, especially in patients with intestinal metaplasia.     

Experimental Barrett's esophagus and the origin of intestinal metaplasia

Many questions remain unanswered regarding the pathogenesis and the cell origin of Barrett's esophagus. Recent studies suggest that progenitor cell populations, which are presumed to reside at the basal layer in the squamous epithelium and at the esophageal glands duct epithelium, may differentiate into a glandular phenotype leading to the development of columnar epithelium in the distal esophagus. Other studies also support the hypothesis that cardiac epithelium may precede the occurrence of specialized intestinal metaplasia. It remains unclear whether cardiac-type epithelium in Barrett's esophagus arises from squamous epithelium or from migration of native cardiac epithelium at the EGJ into the distal esophagus. Experimental animal models of chronic reflux esophagitis, although with some shortcomings when researchers extrapolate the study data to the human situation, have provided interesting insights into possible mechanisms associated with the occurrence of Barrett's esophagus. A better understanding of the molecular mechanisms regulating the development of Barrett's esophagus is necessary for developing new strategies directed toward prevention and treatment of this metaplastic condition with a potential risk for malignant transformation.     

Experimental studies on canine tracheal preservation

Thirty-five adult mongrel dogs were anesthetized and a five-ring segment of cervical trachea was excised. The tracheal defect was restored by end-to-end anastomosis. The autografts were divided into 4 groups as follows; no preservation (control) group (n = 4), graft preserved in Collins solution (n = 11), graft preserved in phosphate buffered extracellular solution (Ep4) (n = 11), and graft preserved in physiological saline solution (n = 11) for 24 or 48 hours at 4 degrees C. After preservation, laparotomy was performed on the animals and the tracheal autograft was wrapped in the distal portion of the omentum. After 21 days all grafts were excised and examined by macroscopically, microscopically and scanning electron microscopically (SEM). The changes of the epithelia glands, and cilia were evaluated, with each item being rated on a point scale (1-3) according to the degree of regeneration and summed to form a total score. The total score of the Collins group was significantly higher than those of the Ep4 and saline groups. The present data suggest that tracheal autografts can be preserved for up to 48 hours in each of the solutions and that Collins solution is preferable for use in canine tracheal preservation.     

犬异体气管移植的实验研究

目的 通过研究与移植气管狭窄相关的因素,寻求可行的解决移植气管狭窄的方法。方法 16只杂种犬随机分为A、B2组,每组8只,行原位气管移植,带血管蒂大网膜包绕。A组犬术后不给予特殊处理,B组犬术后给予免疫抑制剂。术后4周处死动物,行大体及病理学检查,并测定移植气管的通畅度,组织学半定量测定上皮及软骨情况。结果 B组犬移植气管结构保持较好、狭窄程度低、上皮及软骨积分均较A组高,并且2组犬移植体的通畅度与上皮及软骨积分均成正相关。结论 应用免疫抑制剂有助于移植体结构的保持。上皮的再生及软骨的保持与气管移植体的狭窄密切相关。     

Experimental photodynamic treatment of canine bladder

In urology, important limiting factors in the application of hematoporphyrin derivative and photodynamic therapy appear to be the problems of standardization of dosimetry and the technique of transurethral photoradiation. Experimental photodynamic therapy on canine bladder with normal and altered epithelium was performed using an argon laser as an energy source. A 630 nanometer wavelength of light was delivered through a quartz-optical fiber with either a regular flat end for focal illumination or a bulb-type end which produced an isotropic light pattern. It was demonstrated that normal canine bladder was resistant to photodynamic therapy and that the bulb tip produced whole bladder illumination. With a moderate light dose of 18 to 30 Joules/cm.2 the effect following whole bladder illumination on the bladder was generalized and superficial. This approach appears to be ideal for treating superficial transitional cell carcinoma of the bladder. Additional work is needed in selecting appropriate energy doses.     

Experimental end-to-end anastomosis of lymphatic trunks in the canine hind limb

Summary Experimental end-to-end anastomoses were carried out between the femoral lymphatic trunks in the dog. They measured between 0.2 to 0.6 mm. A new triple cut technique is described. The long-term patency rates were, for the no-tension group 25%, for the normal tension group 22%. Result control was performed by re-exploration of each anastomosis.     

Leiomyoma of the oesophagus

Leiomyoma of the oesophagus is an uncommon lesion but should be considered in the differential diagnosis of younger patients presenting with dysphagia or mediastinal mass. This report deals with the management of 14 cases of leiomyoma seen during a 12 year period.     

Pneumomediastinography in carcinoma of the oesophagus

Forty-one patients with carcinoma of the gullet and oesophagogastric junction have been investigated by means of a new pneumomediastinographic method of pertracheal insufflation. More than 1,600 patients suffering from various pulmonary or mediastinal lesions have undergone this simple time-saving procedure. Pneumomediastinography cannot replace radiography of the gullet or oesophagoscopy in cases of cancer of the oesophagus. Since it reveals valuable details, which remain hidden in conventional radiographs or during oesophagoscopy, it may complement the findings of two traditional methods of investigation. The main advantages of pneumomediastinography in the diagnosis of cancer of the gullet are: it permits accurate assessment of the size and shape of the tumour; in patients submitted to radiotherapy, the local response to this treatment may be determined by changes in the size of the tumour shadow in pneumomediastinal tomograms; it establishes reliably that the tumour does not invade the adjacent organs; it facilitates visualization of some of the enlarged lymph nodes in the mediastinum which are not visible in conventional radiographs or tomograms; and the radiological characteristics of these lymph nodes facilitate an approximate differentiation between inflammatory and metastatic enlargements.     

Pseudosarcoma of the oesophagus

Pseudosarcoma of the oesophagus previously has been well documented in only six patients. The present case history illustrates the characteristics originally described by Stout of a polypoid lesion composed of sarcoma-like cells adjacent to squamous cell carcinoma.