Hans Rahbek Sørensen

Regulatory peptides in the lower esophageal sphincter of man.

Smooth muscle specimens were taken from the lower esophageal sphincter of patients suffering from achalasia or hiatus hernia with gastro-esophageal reflux. The specimens were analysed for neurohormonal peptides using immunochemistry and immunocytochemistry. Control specimens were obtained from patients subjected to esophageal resection because of esophageal cancer. The concentration of vasoactive intestinal polypeptide (VIP) was higher and the VIP nerve supply greater in patients with hiatus hernia than in control patients. The VIP nerve supply and the content of this peptide was lower in patients with achalasia than in controls. The same tendency was observed for substance P and enkephalin although the changes in their concentrations were not statistically significant. Enkephalin fibers were few, both in specimens from control patients and from patients with hiatus hernia; they could not be detected in specimens from patients with achalasia. Never fibers containing somatostatin or gastrin/cholecystokinin could not be detected in any of the groups and somatostatin and gastrin/cholecystokinin could not be measured in extracts of the lower esophageal sphincter. We propose that changes in the concentration of neuropeptides may at least contribute to manifestations of achalasia and of decreased lower esophageal sphincter pressure and gastro-esophageal reflux.

Computerized 12-hour simultaneous ECG, pressure- and pH-probe investigation of the oesophagus. Method and reference values in healthy individuals

A computerized 12-h simultaneous ECG, pressure- and pH-probe investigation method of the oesophagus is described, and reference values in healthy individuals presented. The analysing system includes two new elements. An interface box, which detects propagating and retrograde peristalsis, by looking at pressures in the oesophagus. A computer (Hewlett Packard 9845T), which makes the whole analysis automatic, draws a 12-h pH-curve, makes area computations, pH-related swallow registrations and time-pH relationships. The results obtained with this measuring system are in agreement with the results of other similar investigations. It is concluded that area computation is the most accurate method of reflux detection. Furthermore this simultaneous ECG, pressure and pH measuring system is excellent in differentiating between chest pain of cardial and oesophageal origin.

Brain histology, blood-brain barrier and brain water after normothermic and hypothermic cardiopulmonary bypass in pigs.

The effect of hypothermia during cardiopulmonary bypass (CPB) on cerebral histopathology, blood-brain barrier permeability to serum proteins and water content was evaluated. Pigs were subjected to non-pulsatile CPB for 2 h at either normothermia or hypothermia, and a group of anaesthetised pigs served as normothermic controls. The histopathology was assessed on paraffin embedded sections. The permeability of the cerebral vessels was studied by immunocytochemical demonstration of extravasated serum proteins. The cerebral water content was assessed by specific gravity measurements. The histological studies demonstrated hydropic degeneration of the brain parenchyma and perivascular swelling of the astrocytic endfeet throughout both white and gray matter in the normothermic CPB group. Similar changes were not encountered during hypothermic CPB, which suggests a beneficial effect of decreased temperatures on brain tissue during CPB. Neither normothermic nor hypothermic CPB induced significant changes in the cerebrovascular permeability or in the specific gravities.

Distribution and Content of Neuropeptide Y in the Human Lower Esophageal Sphincter

The occurrence and distribution of neuropeptide Y (NPY) was studied in smooth-muscle specimens from the human lower esophageal sphincter region by immunocytochemistry and immunochemistry. Normal individuals and patients suffering from achalasia or hiatus hernia with severe gastroesophageal reflux were examined. NPY fibers were found within and around smooth-muscle bundles of the longitudinal and the circular muscle layers and within the myenteric ganglia. Smooth-muscle specimens from patients with hiatus hernia and gastroesophageal reflux displayed numerous NPY fibers and an increased content of NPY. Specimens from patients with achalasia contained only few NPY fibers and had a decreased content of NPY as compared to specimens from control patients. Conceivably, NPY may play a role in the regulation of the lower esophageal sphincter.

Soluble interleukin-2 receptor and soluble CD8 antigen levels in serum from patients with non-resectable lung cancer

SummaryIn a preliminary longitudinal study two women with histologically verified adenocarcinoma of the lung, without simultaneous infectious or inflammatory conditions, were seen every 2 weeks until death. In one of the patients serum soluble interleukin-2 receptor (sIL-2R) levels rose progressively while the levels for the other patient increased during the second half of the observation period. Serum soluble CD8 antigen (sCD8 Ag) showed a pattern dissimilar to the one for sIL-2R. In a retrospective cross-sectional study circulating levels of sIL-2R and sCD8 Ag were measured before explorative thoracotomy in a total of 65 patients with histologically proven non-resectable carcinoma of the lung. The sIL-2R levels were significantly increased independently of histological subclassification while sCD8 Ag was increased only in patients with small-cell lung cancer. There was no correlation between pre-operative values and length of survival.

Brain damage following low flow cardiopulmonary bypass in pigs.

Reduction of pump flow during cardiopulmonary bypass (CPB) reduces the formation of microemboli and trauma to the blood components, reduces both rewarming of the heart and the noncoronary collateral flow, and improves surgical exposure. Recent studies indicate that a reduction in pump flow, even at normothermia, does not increase the incidence of postoperative cerebral dysfunction. We examined the cerebral consequences of 2 h of normothermic CPB in pigs carried out at pump flows of either 70 ml/kg per min or 50 ml/kg per min, and compared the results with those of a nonperfused control group. We measured the regional cerebral glucose metabolism and the regional capillary diffusion capacity simultaneously in ten different brain regions. Brain morphology, the blood-brain barrier permeability to serum proteins and the regional cerebral water content were also determined in the same animals. Glucose metabolism decreased significantly in both CPB groups (P < 0.001), and significant differences were found between the capillary diffusion capacities of the three groups (P < 0.05), with decreases in eight out of ten brain regions examined in the 50 ml/kg per min group. The results indicate that a reduction of pump flows from 70 ml/kg per min to 50 ml/kg per min is deleterious to the brain, and that a pump flow of 70 ml/kg per min itself has an injurious effect, when normothermic CPB is carried out for 2 h without the use of vasoactive drugs to maintain the blood pressure. Mean arterial blood pressure (MAP) rather than pump flow seemed to determine the adequacy of the cerebral perfusion.