A study of lymphocyte kinetics in nasopharyngeal carcinoma with indium III oxine-labelled lymphocytes

The kinetics of lymphocyte migration in 12 pre-treatment patients with nasopharyngeal carcinoma (NPC) and three cancer controls in remission were studied with Indium III oxine-labelled autologous lymphocytes. The migratory patterns of the labelled lymphocytes were defined by serial gamma imaging and blood clearance of Indium over 72 h. Once in the systemic circulation the labelled lymphocytes migrated immediately to the liver and spleen. In all the subjects studied the lymphocytes began to migrate out of the liver at 0.5 h, only to return to the organ gradually between 2 and 72 h. In the control subjects the lymphocytes migrated out of the spleen from about 4 h. This coincided with a hump in the peripheral blood clearance curve after about 4 h signifying re-entry of the lymphocytes into the vascular space from the spleen. In the 'early' NPC subjects (Stage I-III) the rate at which the lymphocytes entered the spleen was much reduced from about 4 to 72 h, suggesting a prolonged transit time of the lymphocyte through the organ. However, there were still prominent humps in the blood clearance curves, suggesting significant re-entry of lymphocytes into the vascular space. In the 'late' NPC subjects (Stage IV-V), the activity of the spleen was low between 4 and 72 h and there was continuous sequestration of lymphocytes in the organ. Consequently the humps in the blood clearance curves were much reduced or absent. The activities of the metastatic lymph nodes were intense between 2 and 48 h, suggesting marked sequestration of lymphocytes in the diseased lymph nodes. Migration of lymphocytes in the metastatic area of the liver was notably absent and presented as cold areas on gamma scanning. The sequestration of lymphocytes in the spleen and metastatic lymph nodes in 'early' and 'late' NPC could lead to a contraction of intravascular lymphocyte pool and could explain the stage-dependent lymphopenia reported in NPC.

Predictive value of surveillance skin and hub cultures in central venous catheters sepsis

In a prospective study of septic complications of central venous catheters used for total parenteral nutrition, daily surveillance catheter hub cultures and twice weekly skin cultures at the catheter entry site were evaluated for their predictive value for catheter sepsis, i.e. bacteraemia with an identical species as that recovered from the catheter tip, or catheters which grew greater than or equal to 15 cfus by a semiquantitative method and/or greater than or equal to 10(3) cfus by a quantitative method. Of 142 catheters studied, 29 were identified to have catheter sepsis. For these the sensitivity of the surveillance hub culture was 34.5% and the sensitivity of the skin culture was 37.9%. When either the hub or the skin culture result was considered as an indication of catheter sepsis, the sensitivity increased to 79.3%. The positive and negative predictive value of the combined result was 44.2% and 93.3% respectively. This study suggests that simultaneous hub and skin cultures are required for a satisfactory surveillance.

Glutathione reductase: solvent equilibrium and kinetic isotope effects

Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. With NADPH or GSSG as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinetic isotope effects were observed on V but not V/K. Plots of Vm vs mole fraction of D2O (proton inventories) were linear in both cases for the yeast, spinach, and human erythrocyte enzymes. When solvent kinetic isotope effect studies were performed with DTNB instead of GSSG as an alternate substrate, a solvent kinetic isotope effect of 1.0 was observed. Solvent kinetic isotope effect measurements were also performed on the asymmetric disulfides GSSNB and GSSNP by using human erythrocyte glutathione reductase. The Km values for GSSNB and GSSNP were 70 microM and 13 microM, respectively, and V values were 62 and 57% of the one calculated for GSSG, respectively. Both of these substrates yield solvent kinetic isotope effects greater than 1.0 on both V and V/K and linear proton inventories, indicating that a single proton-transfer step is still rate limiting. These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition. Finally, the solvent equilibrium isotope effect measured with yeast glutathione reductase is 4.98, which allows us to calculate a fractionation factor for the thiol moiety of GSH of 0.456.

Low volume intercostal injection. A comparative study in patients and cadavers

This study compared the spread of 3 ml of a solution of bupivacaine-methylene blue in the intercostal space of patients and cadavers. There were 51 successful injections in each group which demonstrated in 86% of patient injections and 84% of cadaver injections that spread was confined to one intercostal space. Spread was more extensive in cadavers, probably as a result of autolysis. It would therefore still appear necessary, when low volumes of local anaesthetic are used, to block each intercostal nerve individually.

Healing of esophageal fistulas after surgical treatment for carcinoma of the esophagus and the upper part of the stomach

In a series of 132 patients who had undergone surgical treatment for carcinoma of the esophagus and upper part of the stomach, anastomotic leakage occurred in 29. We retrospectively studied the factors that could influence the healing of the fistulas in the management of this condition. Despite adequate supportive treatment, including total parenteral nutrition, five patients died from unrelenting infection. Fifteen fistulas closed spontaneously after an average of about four weeks of conservative treatment and full nutritional therapy. Those patients who had persistent fistulas after similar treatment were found to have either residual tumor after palliative operation or preoperative serum albumin levels that were lower than those of the other group. Prolonged conservative treatment for persistent fistulas may not be warranted if such risk factors are identified, and surgical repair should be considered.

Intra-operative localization of bleeding small intestinal lesions

We prospectively studied 12 patients to compare fibreoptic enteroscopy and methylene blue injection through superselectively prepositioned angiographic catheters in intra-operative localization of bleeding small intestinal lesions. Four patients were excluded because the lesions were easily detected by gross examination. Eight patients were subjected to study by these two methods. As methylene blue injection required a positive angiography, it was possible only in five patients. In two of these five patients, non-bleeding lesions were present outside the intestinal segments localized by this method. Enteroscopy was simple, accurate and reliable in seven patients. Complete enteroscopy was impossible in one patient with advanced lymphoma because the intestine and its mesentery were matted together. Fortunately, the bleeding ulcers were still within the reach of the endoscope. Enteroscopy localized bleeding small intestinal lesions more exactly than methylene blue injection so that the length of gut resection could be shorter. We, therefore, conclude that enteroscopy is the better intra-operative localization procedure.

Limitations and dangers of gastrografin swallow after esophageal and upper gastric operations

In a series of 135 patients who underwent esophageal and upper stomach surgery, the incidence of anastomotic leakage was 20.4 percent. One hundred four patients had either Gastrografin swallow or the methylene blue test to evaluate anastomotic integrity before resumption of oral feeding. Both tests were disappointing in that methylene blue failed to detect any case of leakage and Gastrografin swallow could only detect three cases of subclinical leakage. The high false-negative detection rate of Gastrografin swallow might be related to the inferior radiographic detail provided by this contrast medium. Aspiration of Gastrografin is potentially dangerous and could be fatal. We believe that barium sulfate, which provides better radiographic detail and is not so hazardous when aspirated, should be the contrast medium of choice.

Influence of surgeons' experience on postoperative sepsis

A prospective study was performed on 635 patients with appendicitis operated on by 7 trainees and 119 patients operated on by 6 senior surgeons with more than 8 years of surgical experience. In patients with normal appendices, postoperative sepsis was extremely low. For early and late appendicitis, the infection rates of the trainees decreased as experiences accumulated, but they were still higher than that of the senior surgeons. The difference in infection rates in acute appendicitis did not reach statistical significance between any of the training stages and between the various stages and the rate of the senior surgeons. The differences in infection rates in late appendicitis between stage 1 and stage 3 was significant, as was the difference in infection rates between stage 1 and the infection rate of the senior surgeons. Therefore, we have concluded that overall, the limited experience of trainees is related to the rate of postoperative sepsis in late appendicitis, although the infection rates of individual trainees vary a lot.

Optimal irrigation pressures in operative choledochoscopy

A prospective study was conducted on 20 consecutive patients who underwent elective exploration of common bile-ducts for stones to determine the optimal irrigation pressures in choledochoscopy. Ten patients had rigid choledochoscopy and 10 patients had flexible choledochoscopy. Choledochoscopic views were assessed at low irrigation pressure (irrigant delivered at hydrostatic pressure of 1 m of water or 80 mmHg) and high irrigation pressure (irrigant delivered at cuff pressure of 300 mmHg plus hydrostatic pressure of 80 mmHg). Choledochoscopic views were better with high than low irrigation pressures for rigid choledochoscopy. However, there was little difference in the views for flexible choledochoscopy. Common bile-duct pressures were measured with irrigant delivered at pressures 80-380 mmHg at intervals of 50 mmHg. With increasing irrigation pressures, the common duct pressures rose and they were consistently higher in flexible than rigid choledochoscopy. The common duct pressures in rigid choledochoscopy never exceeded the recommended safety limit, even at the high irrigation pressure of 380 mmHg. With flexible choledochoscopy, the common duct pressure was below the recommended safety limit only with low irrigation pressure of 80 mmHg. Therefore, it is recommended that a high irrigation pressure of 380 mmHg for rigid choledochoscopy and a low irrigation pressure of 80 mmHg for flexible choledochoscopy be used.

ack::Mu d1-8 (Apr lac) operon fusions of Salmonella typhimurium LT2

Several ack::Mu d1-8 insertions were isolated from Salmonella typhimurium on MacConkey-glucose-trimethylamine oxide medium. They could not produce gas from glucose in the absence of exogenous formate. Two of the mutants expressed beta-galactosidase activity and were shown to be ack::Mu d1-8 fusions by genetic analysis. These insertions were characterized and located on the genetic map at the ack locus by co-transduction with zei::Tn10. The gene order zei::Tn10-ack-pta was established. The direction of transcription of ack was clockwise on the genetic map. Expression of the lac operon in ack::Mu d1-8 was increased twofold by anaerobiosis. Addition of formate, pyruvate, and acetate did not affect the anaerobic expression of the lac operon in ack::Mu d1-8.

Surgical management of strictures of the major bile ducts in recurrent pyogenic cholangitis

Definitive surgical procedures were performed on 46 patients with strictures of the major bile ducts: dilatation of strictures was undertaken in 6 patients, hepatotomy and plastic repair in 2, biliary-enteric anastomosis in 18, and liver resection with or without drainage for the rest of the biliary tree in 20 patients. The overall operative morbidity was 21.7 per cent. Two patients died within 30 days of operation. One patient died of septicaemia after emergency dilatation of stricture while another died of sepsis from a leakage after hepatotomy and plastic repair. The median follow-up for the 44 patients who survived the operation was 43 months. All strictures reformed after dilatation within 2 months. Acute cholangitis occurred in six patients, two after dilatation of strictures (with documented recurrent stone formation in one), two after biliary-enteric anastomosis and two after liver resection. Thus, good clinical results were obtained in 38 out of 44 patients (86.4 per cent).

Acute appendicitis in children

A prospective study was conducted on 344 children aged from 3 months to 16 years with acute appendicitis. Most children presented with typical features of acute appendicitis (70%) or peritonitis (28%). Atypical presentation was uncommon and occurred only in seven young children, masquerading as intestinal obstruction, gastroenteritis or urinary tract infection. Prolonged delay in surgery was associated with a rise in incidence of late appendicitis (gangrenous and perforated appendicitis). This rise was especially marked 37 h after onset of symptoms. The main causes of delay were inability of the parents and primary care medical practitioners to recognize the disease early. Surgeons contributed very little to the delay. High risk factors for postappendectomy sepsis were young children under 6 years old, late appendicitis, obese patients, inferior systemic antibiotic regimes and inexperienced surgeons. Young children had high postoperative sepsis mainly because of the high incidence of late appendicitis due to their inability to express their symptoms properly. They were not especially prone to postappendectomy sepsis; they had the same degree of appendicitis compared with older children. Measures to decrease the postappendectomy morbidity are suggested.

Intercostal catheterisation. An alternative approach to the paravertebral space

Twenty-one patients scheduled to undergo thoracotomy or median sternotomy had intercostal catheters inserted pre-operatively. During thoracotomy, under direct vision, the spread of 20 ml of a solution containing bupivacaine and methylene blue was followed. In most cases the spread involved one or two intercostal spaces. However, in all but one patient, dye spread medially to the paravertebral space where it then spread in both caudad and cephalad directions to reach between two and five vertebrae. In three cases, dye was seen crossing the anterior surface of the vertebrae to reach the contralateral aspect. It is concluded that a major component of dermatomal block during intercostal catheterisations may be secondary to paravertebral spread.

A scientific evaluation of operative choledochoscopy in acute cholangitis

A prospective study to determine the safety and effectiveness of choledochoscopy in acute cholangitis and acute suppurative cholangitis due to common bile duct stones was conducted on 70 patients. Common bile duct pressures determined on the first 20 patients showed that choledochoscopy was unlikely to cause cholangiovenous reflux. Laboratory and clinical parameters revealed that choledochoscopy did not cause septicemia, worsen cholangitis, or provoke acute pancreatitis. There was no iatrogenic injury during choledochoscopy, and the choledochoscopic views were minimally affected by cholangitis. Choledochoscopy detected overlooked stones after conventional methods of exploration of common bile ducts in 14.3% of patients and it helped to remove impacted stones in 2.9% of patients. As a result, the incidence of retained stones after choledochoscopy was 1.4%. Time spent in choledochoscopy was short, and the total postoperative septic complication rate was only 10%. There was no operative mortality. It is concluded that choledochoscopy is safe and effective in cholangitis.

Preoperative and intraoperative localisation of gastrointestinal bleeding of obscure origin

In the past six years, 37 patients with gastrointestinal bleeding of obscure origin had their bleeding sites localised preoperatively or intraoperatively. Preoperative investigations followed a regime consisting of endoscopy, barium meal and follow through, small bowel enema, 99mTc pertechnetate scan, 99mTc-labelled red blood cell scan and selective coeliac and mesenteric angiography. Bleeding lesions were localised preoperatively in 36 patients. In one patient, diagnostic laparotomy had to be carried out immediately before any investigation because the bleeding was severe. At operation, angiosarcoma of ileum was found. Unless preoperative investigations showed the lesions to be in anatomically fixed organs like the duodenum or colon, the lesions had still to be found at operation. Palpation and transillumination detected the lesion intraoperatively in 21 patients while only some lesions were found in three patients with multiple lesions. Sigmoidoscopy through enterotomies was required in one patient. Intraoperative enteroscopy was done for small lesions not found grossly at operation in nine patients, to detect additional lesions in three patients or to rule out suspicious lesion shown on preoperative tests in one patient. In another patient with diffuse lymphoma of small bowel with bleeding from only a small segment of jejunum, injection of methylene blue intraoperatively through a previously placed angiographic catheter stained the bleeding segment of jejunum blue. This segment was identified easily and resected. These preoperative and intraoperative localisation procedures were simple and effective and we recommend them to be used more freely.

Chronic sinopulmonary disease in Chinese patients with obstructive azoospermia

The prevalence of chronic infections of the nasal sinuses and the lung (chronic sinopulmonary disease) was investigated in 33 Chinese patients with obstructive azoospermia who were compared with 32 patients with azoospermia due to failure of the germinal epithelium. Ten out of the group of 33 patients with obstructive azoospermia had congenital absence of the vas and/or epididymis and were excluded from that group. The patients with obstructive azoospermia had normal testis size, normal levels of serum FSH and LH, lower seminal fluid fructose, and a higher incidence of serum sperm agglutinating and immobilizing antibodies when compared with the group with damage to the germinal epithelium. The number of patients with symptoms of chronic sinopulmonary infections were similar in all groups. One patient with obstructive azoospermia had bronchiectasis. All other patients had normal chest x-ray studies. About 40% of the patients in all three groups had abnormal sinus X-rays. However, the nonsmoking patients with obstructive azoospermia had a statistically significant (P less than 0.05) lower mid-expiratory flow rate than the nonsmoking patients with nonobstructive azoospermia. Only three additional patients with obstructive azoospermia had both abnormal sinus x-ray and a reduced mid-expiratory flow rate, suggestive of Young's syndrome. It was concluded that Young's syndrome (sinopulmonary infections associated with acquired obstructive azoospermia) is much less common in Chinese men (four out of 23, 17%) and their sinopulmonary problems are less severe than in Caucasians.

Prediction of postoperative pulmonary complications in oesophagogastric cancer surgery

In a series of 102 patients with cancer of the oesophagus or gastric cardia in whom surgery had been performed, postoperative respiratory infection, respiratory failure and mortality secondary to respiratory complication occurred in 55.8, 34.3 and 21.6 per cent respectively. The incidence of complications correlated well with the pre-operative peak expiratory flow rate when it was less than 65 per cent of the predicted normal value. However, the predictive ability of peak expiratory flow rate was much less than the patient's age, pre-operative serum albumin level, pre-operative Pa,O2 and number of surgical wounds when all risk factors were considered. Significantly more complications occurred when the patient was greater than 65 years old, Pa,O2 was less than 10 kPa, serum albumin was less than 39 g/l and when the operation required three incisions. These findings may serve as guidelines for identification of high-risk patients in the future.

Localized amyloidosis of the ureter

An unusual case of localized amyloidosis of the ureter is described. Suspicion of the condition was first raised during operation when a frozen section was examined. An unnecessary nephrectomy was thus spared. It is a rare condition and awareness of the entity is required to recognise it clinically, radiologically or pathologically. The pathogenesis of localized amyloidosis is briefly discussed.

Conventional vs. triple rubber band ligation for hemorrhoids. A prospective, randomized trial

Two hundred five patients with symptomatic first- and second-degree hemorrhoids were randomized to receive either conventional rubber band ligation or triple rubber band ligation. In conventional rubber band ligation, the hemorrhoids were ligated at one primary site per session at intervals of four weeks until symptoms were relieved or when all three hemorrhoids were ligated. In triple rubber band ligation, all three primary hemorrhoids were ligated in a single session. After completion of treatment, the patients were examined every three months, or earlier if symptoms recurred. Both methods were effective in the treatment of early hemorrhoids and the incidence of postligation pain and complications was similar. The advantages of having the treatment completed at the initial visit in triple rubber band ligation are obvious. Furthermore, less treatment sessions were required for triple rubber band ligation to control symptoms than for conventional rubber band ligation. Triple rubber band ligation is more cost-effective and therefore is recommended.

Combined topical povidone-iodine and systemic antibiotics in postappendicectomy wound sepsis

Three hundred and fifteen patients with appendicitis were randomized into two groups. One group received pre-operative systemic gentamicin and metronidazole while the other group received 1 per cent topical povidone-iodine solution in addition to the antibiotics. For early appendicitis including normal and acutely inflamed appendices, only one dose of antibiotics was used. The postoperative wound sepsis was very low in both groups of patients and there was no statistical difference between them. For late appendicitis including gangrenous and perforated appendices, the antibiotics were continued for 7 days. Eight out of 51 patients who had the topical agent developed wound sepsis compared with one out of 52 patients who received no topical agent. This difference is statistically significant (P = 0.03). All wound infections presented within 2 weeks of operation and were deep. Povidone-iodine, 1 per cent, adversely affects the wound infection rate in late appendicitis and should not be used.