Gastrin in human bronchogenic carcinomas: constant expression but variable processing of progastrin.

Using a library of radioimmunoassays against essential sequences of human progastrin and procholecystokinin, we have examined the occurrence of gastrin, cholecystokinin, and their precursors in bronchogenic adenocarcinomas, large-cell, small-cell, and squamous-cell carcinomas (n = 17). Progastrin and some of its bioactive (i.e., alpha-carboxyamidated) products were present in all tumors, irrespective of histological classification. The concentration of progastrin varied from 0.2 to 21.9 pmol/g tissue; glycine-extended intermediates constituted less than 0.1 to 0.5 pmol/g; and bioactive, carboxyamidated gastrin ranged from less than 0.1 to 6.1 pmol/g. Chromatography showed that the bioactive gastrins were exclusively gastrin-17 peptides, half of which were tyrosine O-sulfated. Neither procholecystokinin nor its processing products were found in the tumor extracts. Six samples of nonneoplastic human lung tissue contained traces of progastrin (range, less than 0.1-0.8 pmol/g), but neither bioactive gastrins nor any cholecystokinin. The results show that the gastrin gene is expressed in all classes of bronchogenic carcinomas. Due to incomplete posttranslational processing measurement of progastrin may be necessary to detect such expression.

Cell-specific processing of pro-cholecystokinin and pro-gastrin.

The present review argues that the gastrin-cholecystokinin family is a suitable model for the study of cell-specific processing of pro-hormones. First, the homologous active site of the hormones is a precisely defined tetrapeptide amide, which is well preserved during evolution. Second, the genes of both hormones are translated in a variety of cells (neurons, endocrine cells, paracrine cells, lymphocytes, etc,), but to a varying degree during ontogenesis and pathogenesis of various diseases. Third, each pro-hormone contains multiple processing sites (mono- and dibasic cleavage sites, amidation sites and consensus sequences for seryl phosphorylation and tyrosyl sulfation) leaving ample room for variations in the post-translational processing. The review discusses examples of cell-specific processing that appears to be functionally expedient.

Non-sulphated cholecystokinin in human medullary thyroid carcinomas.

The expression of gastrin/cholecystokinin (CCK) peptides and their precursors was examined in 16 medullary carcinomas of the human thyroid. Measurements with libraries of sequence-specific radioimmunoassays before and after enzymatic cleavage of extracts and chromatographic fractions showed that the carcinomas contained 1.7 pmol carboxyamidated CCK/g tissue (median; range 0.6-21.8 pmol/g), 0.9 pmol glycine-extended precursor/g (median; range less than 0.2-2.3 pmol/g) and 2.3 pmol further COOH-terminal-extended proCCK/g (median; range 0.9-6.2 pmol/g). Neither carboxyamidated gastrins nor any progastrins could be measured. Gel and reverse-phase chromatography revealed only small molecular forms, i.e. greater than 90% of the amidated immunoreactivity eluted like non-sulphated CCK-8 or CCK-7. The results show that human medullary thyroid carcinomas synthesize CCK peptides. The predominance of non-sulphated CCK is unusual. Taken together with earlier observations from dogs and pigs, our results raise the possibility that small non-sulphated CCK peptides modulate thyroid C-cell secretion in an autocrine manner.

Expression, but failing maturation of procholecystokinin in cerebellum.

The cerebellum is the only region of the central nervous system which has been found to be devoid of cholecystokinin (CCK). The assays used, however, have been directed against the alpha-amidated C-terminus of fully processed CCK peptides. Using Northern blot analysis and a library of radioimmunoassays specific for different sequences of proCCK in combination with chromatography and enzyme cleavage, we have now examined the expression and processing of proCCK in fetal, neonatal and adult cerebellar tissue from man, pig and rat. In rat cerebellum CCK mRNA was present already in the fetal state. Two weeks after birth the concentrations declined. Also proCCK was found in significant concentrations in the fetal human and rat cerebellum (approximately 20 pmol/g); but already before birth the expression began to decrease towards low concentrations in adults. The adult porcine cerebellum contained 3.2 pmol proCCK and glycine-extended processing intermediates per gram (range less than 0.1-10.4 pmol/g), and 0.8 pmol carboxyamidated CCK per gram (range 0.1-4.1 pmol/g) varying in size from CCK-58 to CCK-5. For comparison, the adult porcine cerebral cortex contained 757 pmol carboxyamidated CCK/g, 20 pmol glycine-extended CCK/g and no proCCK. We conclude that cerebellum expresses proCCK with the highest level of expression in fetal life. In comparison with other regions of the brain, the maturation to transmitter-active, carboxyamidated CCK peptides is, however, attenuated in both fetal and adult cerebellar tissue.

Procholecystokinin processing in rat cerebral cortex during development.

Using a library of radioimmunoassays for essential sequences of procholecystokinin (proCCK), we have examined the post-translational processing in the rat cerebral cortex from fetal to adult state. The concentration of proCCK in the fetal cerebral cortex was 43 +/- 7 pmol/g tissue (wet weight; mean +/- S.E.M. (n = 20)). It remained constant until day 21 post partum, after which it decreased to undetectable levels. In contrast, the concentration of fully processed, bioactive CCK peptides (i.e. alpha-carboxyamidated CCK) rose from 2 +/- 1 pmol/g in the fetal cortex to 122 +/- 21 pmol/g in the adult. A particularly steep increase occurred from day 7 post partum (13 +/- 2 pmol/g) to day 21 (108 +/- 11 pmol/g). The concentration of glycine-extended intermediates rose gradually from 8 +/- 1 pmol/g in the fetal brain to 55 +/- 6 pmol/g in the adult. Gel chromatography of cortical extracts from day 7, 21 and 100 confirmed the variable processing at the C-terminal amidation site. The results show that the CCK gene is expressed as proCCK already in the fetal brain. However, the covalent modifications of proCCK follow different time courses so that only a small fraction reaches maturation until the first week post partum. We conclude that expression of transmitter-active CCK peptides in the brain is largely regulated at the post-translational rather than at the transcriptional level.

Gastrointestinal transit after laparoscopic versus open colonic resection.

BACKGROUND: Multimodal rehabilitation with epidural analgesia, early oral nutrition and mobilization, and laxative use has decreased the duration of ileus after colonic surgery to about 2 days, as compared with the usual 3 to 5 days of rehabilitation required after open surgery and the slightly shorter time required with laparoscopic surgery. Gastrointestinal transit after colonic resection with laparoscopy or laparotomy was assessed. METHODS: In this study, 32 patients randomized to laparoscopic or open colonic resection received 4 MBq of 111indium diethylenetriamine pentaacetic acid, a tracer, at the end of surgery. Images of the abdomen were obtained 24 and 48 h postoperatively. An opaque abdominal dressing blinded care personnel and patients to the procedure. RESULTS: Defecation occurred on median day 2 postoperatively in both groups. At 48 h postoperatively, 53% of the tracer was excreted by patients in the laparoscopic group, as compared with 26% in the open group ( p > 0.05). CONCLUSION: Postoperative ileus and gastrointestinal transit normalized within 48 h after colonic resection in the patients who received multimodal rehabilitation. No significant difference was observed between the patients who underwent the laparoscopic procedure and those who underwent the open procedure.

Impact of hand dominance, gender, and experience with computer games on performance in virtual reality laparoscopy.

BACKGROUND: The impact of gender and hand dominance on operative performance may be a subject of prejudice among surgeons, reportedly leading to discrimination and lack of professional promotion. However, very little objective evidence is available yet on the matter. This study was conducted to identify factors that influence surgeons' performance, as measured by a virtual reality computer simulator for laparoscopic surgery. METHODS: This study included 25 surgical residents who had limited experience with laparoscopic surgery, having performed fewer than 10 laparoscopic cholecystectomies. The participants were registered according to their gender, hand dominance, and experience with computer games. All of the participants performed 10 repetitions of the six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) within 1 month. Assessment of laparoscopic skills was based on three parameters measured by the simulator: time, errors, and economy of hand movement. RESULTS: Differences in performance existed between the compared groups. Men completed the tasks in less time than women ( p = 0.01, Mann-Whitney test), but there was no statistical difference between the genders in the number of errors and unnecessary movements. Individuals with right hand dominance performed fewer unnecessary movements ( p = 0.045, Mann-Whitney test), and there was a trend toward better results in terms of time and errors among the residence with right hand dominance than among those with left dominance. Users of computer games made fewer errors than nonusers ( p = 0.035, Mann-Whitney test). CONCLUSIONS: The study provides objective evidence of a difference in laparoscopic skills between surgeons differing gender, hand dominance, and computer experience. These results may influence the future development of training program for laparoscopic surgery. They also pose a challenge to individuals responsible for the selection and training of the residents.

Processing-independent analysis (PIA)--a new diagnostic tool.

Posttranslational processing is an important phase of the expression of most eucaryotic genes in terms of functional proteins. Among these, secretory proteins and peptides are of particular interest for clinical chemists, since diagnostic measurements of circulating proteins and peptides constitute a major discipline in clinical chemistry. The posttranslational covalent maturation of secretory proteins and peptides involves multiple enzymatic modifications of the corresponding proproteins along the intracellular secretory pathway. During the eighties, an increasing amount of evidence has indicated that sick secretory cells fail to process their secretory products normally. The diseased cells therefore fail to process their secretory products normally. The diseased cells therefore release also incompletely processed precursors and processing-intermediates. In order to measure the degree of disease, assays that measure proteins and peptides independent of the degree of processing are therefore desirable. We have now designed a new analytical principle, according to which secretory proteins, peptides and their precursors can be accurately quantitated irrespective of the degree of processing. This principle, named processing-independent analysis (PIA), is generally applicable to all cellular synthesized substances. The principle has been applied to and developed first for a well-defined secretory peptide system, progastrin and its products. Using this model, the results obtained so far confirm the diagnostic superiority of processing-independent analysis in comparison with conventional assays for bioactive peptides.

The unique specificity of antibodies in modern radioimmunochemistry--an essay on assays.

The gradual recognition and exploitation of the specificity of antibodies in peptide radioimmunoassays (RIA) during the last three decades are reviewed. From the old fashioned RIA techniques of the sixties through sequence-specific RIA libraries of the seventies to residue-specific immunoassays of the eighties, the RIA technique has to an increasing degree been based on the ability to select strictly monospecific antibodies in high-titered polyclonal antisera. High-avidity monospecific antibodies from polyclonal antisera provide the RIA technology of to-day with unrivalled specificity. This specificity again has increased the utility of RIA as a tool in basic as well as clinical biochemistry.

[Pain and convalescence after ambulatory inguinal herniotomy during local anesthesia]. / Smerter og rekonvalescens efter ambulant ingvinal herniotomi udført i lokal anaestesi.

Postoperative pain and convalescence following ambulatory inguinal herniotomy in local infiltration anesthesia was evaluated in this descriptive study. Sixty consecutive patients (median age 63 yr) were included. Per- and postoperative pain treatment were pre- and postoperative oral tenoxicam and methadone plus infiltration of the surgical field with up to 60 ml of 0.25% bupivacaine. Intraoperative pain intensity was slight and was treated with supplemental bupivacaine. Patients were totally relieved of pain at rest and during mobilisation in the first hours after surgery, but more than half of the patients had moderate pain from the first to the third postoperative day and still had light pain seven days after surgery. Normal daily activity was re-established five days postoperatively (median). Fifty-two patients were satisfied with the anesthesia and eight patients not satisfied due to fear of intraoperative pain. This study shows that inguinal herniotomy can be performed routinely as an outpatient procedure under local infiltration anesthesia. However, late postoperative pain was significant and should be improved with multi-modal analgesia.

[Multiple endocrine neoplasms type I]. / Multipel endokrin neoplasi type I-krise.

The patient had been treated ten years previously for acromegaly. At present he was in hypercalcaemic crisis owing to multiple hyperparathyroid adenomas. He had multiple small pancreatic glucagonomas and a malignant duodenal gastrinoma which led to recurrent episodes of duodenal and gastric ulcers with perforations and hemorrhages. The hypercalcaemia increased the hypergastrinaemia significantly and probably accelerated the ulcer diathesis. This patient illustrates well how severe and complicated the clinical situation can be in patients with MEN-1 and emphasizes the importance of being aware of the syndrome.

[Laparoscopic parietal cell vagotomy. Preliminary results]. / Laparoskopisk parietalcellevagotomi. Proeliminoere resultater.

The results from 11 laparoscopic parietal cell vagotomies are presented. The procedure could be carried out in all patients. The median day of discharge after the procedure was day 1 (range 1-16), median convalescence time 7 (range 4-50) days. One patient required re-operation due to a perforation at the lesser curvature. This complication is ascribed to the learning phase. If a sufficient reduction in gastric acid secretion can be documented in a larger series of patients, laparoscopic parietal cell vagotomy should be considered a serious alternative to conservative treatment.

[Laparoscopic cholecystectomy--minimally invasive surgery]. / Laparoskopisk kolecystektomi--minimal invasiv kirurgi.

In 1987, Mouret devised a technique of performing cholecystectomy through a laparoscope. When performed correctly and on the right indications, this type of minimal invasive surgery has distinct advantages for the patients. Postoperative hospitalization is reduced to a few days and most of the patients can return to work or normal activities within a week or two. In this department, laparoscopic cholecystectomy was used for treatment of symptomatic gallbladder stones in 34 patients. In three patients the procedure was converted to an open laparotomy. No mortality and no ductal injuries were observed and no re-operations were necessary. The operating time averaged 102 minutes and the postoperative stay was 2.3 days. The average duration of sick-leave was 12 days. We are convinced, that this new technique will play a dominant role in the future treatment of symptomatic cholelithiasis.

[Two days' hospital stay after laparoscopic colon resection]. / To døgns indlaeggelse efter laparoskopisk colonresektion.

In order to reduce surgical stress-induced dysfunction and morbidity in the postoperative period after colon cancer surgery in old people, we performed the operations laparoscopically and optimized the postoperative regime especially as regards to treatment of pain, early oral intake and mobilisation. The patients were treated with continuous epidural infusion of local anaesthetic for 48 hours postoperatively. Morphine was avoided. Normal oral intake was allowed immediately after operation and active mobilisation was ensured. Twenty patients with a median age of 81 years (71-92 years), who preoperatively were able to take care of themselves at home, entered the study. In four the operation was converted to open surgery due mainly to growth of the cancer into neighbouring organs. One patient had to have an open reoperation due to small bowel strangulation. Fifteen followed the scheduled programme. They all had normal bowel function on day one or two and were mobilised for eight hours on day two and 12 hours on day three. Accordingly postoperative hospital stay was only two days (median), and the high level of activity continued at home after discharge. The combination of laparoscopic mini-invasive surgical technique and a postoperative regime that optimized pain treatment, early oral intake and active mobilisation considerably reduced postoperative convalescence after colon cancer surgery in old patients.

[A local course on conventional and laparoscopic surgical techniques. A supplement to surgical education]. / Lokalt kursus i konventionel og laparoskopisk kirurgisk teknik. Et supplement til den kirurgiske uddannelse.

In order to increase the possibilities for learning accurate surgical technique in gastrointestinal surgery, we have established a local course for operative training of the registrars. We used organs from pigs--stomach, intestines and liver/gallbladder. They were collected from the local abattoir with assistance from a vet. Conventional gut anastomosis and gastroenteroanastomosis were performed with "two-layer" and "one-layer" techniques. Laparoscopic cholecystectomy was performed with the liver-gallbladder organ block placed in a "black box", in which the organ was perfused with red fluid--a Pulsatile Organ Perfusion System. The registrars' evaluations of the course were very positive. They all thought that the course gave them opportunities for surgical training that were not available in the busy daily routine. The course now forms part of the education programme for surgical registrars in our department.

[Changed working plans can improve medical training]. / En aendret arbejdstilrettelaeggelse kan medføre en forbedret laegeuddannelse.

INTRODUCTION: The quality of clinical medical training in Denmark has been closely debated and criticised in recent years. Reorganisation of the daily working plans is one of the recommendations for improvement. METHOD: In the Department of Gastrointestinal Surgery, we made changes in the daily working plans in order to improve supervision and training. These changes included firmer attachment of the young residents to specialised medical teams in the department and the creation of more supervised working situations. The morning rounds were done by all the senior and junior doctors in the team together, which meant that the rounds could be completed in half-an-hour and consequently more senior doctors were available for supervision during the rest of the day. This was adopted by the outpatient clinic, the endoscopy unit, and the operating rooms, where activities did not start until after the rounds. RESULTS: The changes led to a considerable increase in the number of working situations with supervision. Assessment by a questionnaire showed that residents also found significant improvements in supervision during all clinical activities. Overall satisfaction with the department and working conditions increased. CONCLUSION: Many different aspects must be considered if clinical medical training is to improve. One key factor is a thorough revision of the daily working plans, so as to establish as many supervised teaching situations as possible.

[Laparoscopic fundoplication in gastroesophageal reflux]. / Laparoskopisk fundoplikation ved gastroøsofageal refluks.

Gastro-oesophageal reflux disease (GORD) is a chronic disorder requiring lifelong medical therapy or surgery. In the present study we evaluated the postoperative course and effect of laparoscopic fundoplication on GORD in 27 patients with a median age of 44 (range 27-73) years. Fifteen were operated on with a Watson procedure, and 12 patients had a Nissen procedure. Median stay and convalescence after surgery was one and 10 days respectively. Three patients had to be converted into open surgery (bleeding: two, unclear anatomy: one). No major complications were seen, but four patients had postoperative complications (stenosis requiring dilatation: one, subcutaneous emphysema: one, wound sepsis: one, hernia: one. The two latter complications were seen in converted patients). Two patients had prolonged dysphagia, and two patients needed slight dietetic advice for gasbloat syndrome. In 25 of 27 patients good control of GORD was accomplished as judged by symptomatology, endoscopy and 24-hour pH measurements. It is concluded that laparoscopic fundoplication offers good control of GORD with few complications, and short hospital stay and convalescence.

[Laparoscopic excision of the rectum. An advanced technique or true clinical progress?]. / Laparoskopisk rectumeksstirpation. En avanceret teknisk øvelse eller et reelt klinisk fremskridt?

A very high postoperative morbidity is seen after conventional open abdominoperineal excision of the rectum. The use of laparoscopic technique for this operation implies theoretical benefits, but only sparse clinical data have been published and advantages have not yet been convincingly documented. In the light of our experiences with laparoscopic colonic resections in high-risk patients and in two patients with abdominoperineal excision we propose the following perioperative regime for elderly patients undergoing rectal excision: Laparoscopic operation followed by continuous epidural analgesia, opioid-free pain treatment, restricted administration of fluids perioperatively, early enteral nutrition and enforced mobilisation as well as intensified training in colostomy care-that should already be started preoperatively. Preliminary results suggest that morbidity and the need for hospital stay can be considerably reduced by such an approach. A prospective evaluation of this strategy on the immediate postoperative results will be followed by long-term results concerning survival, local recurrence rates, distant metastases and the risk of port-site metastases.

Effects of omeprazole on acid secretion and acid-related symptoms in patients with Zollinger-Ellison syndrome.

In the Zollinger-Ellison syndrome, symptoms and complications are due to hypersecretion of acid, and the first therapeutic step is to suppress the acid secretion. Long-term treatment with histamine H2-receptor antagonists was compared with omeprazole treatment. A total of 30 consecutive ZES patients were treated continuously with H2-receptor antagonists. During long-term treatment, a marked tachyphylaxis was noted, more than 50% of the patients had periods of dyspepsia, recurrent ulcers were found in 10 patients and in 16 a decline in the action of the H2-receptor antagonist required a change to omeprazole after a median duration of 36 months. A total of 22 patients were treated with omeprazole. During long-term treatment, the dose could be reduced slightly. Inhibition of acid secretion was maintained in all cases, and none had dyspeptic symptoms. The median duration of treatment was 18 months, with a range of 1-120 months (H2-receptor antagonists) and 27 months with a range of 1-66 months (omeprazole). No side-effects were seen with omeprazole.

Gastroenteropancreatic tumours and prohormones.

The structures and post-translational maturation of pancreatic and gastrointestinal prohormones are reviewed with emphasis on Danish contributions to today's knowledge. The review describes general, cell-specific, and tumour-specific prohormone-processing patterns. Since prohormone-processing in endocrine tumours is often attenuated, conventional assays that measure only the phenotypic endpoint of hormone gene expression (i.e. the bioactive hormone) do not quantitate tumour activity accurately. In contrast, measurements that include also prohormones and processing intermediates provide more accurate data on hormone synthesis in gastroenteropancreatic endocrine tumours. In order to comply with such demands we have developed a new analytical principle (processing-independent analysis (PIA)) which quantitates the entire translation product irrespective of the degree of processing. The significance of PIA in routine diagnostics awaits prospective evaluation. We hope that the present review illustrates how the tumour biology of endocrine cells in the pancreas and the gut has been an essential research area in Danish gastroenterology and endocrinology--one purpose being improvement of early diagnosis of endocrine tumours in the gut and the pancreas.