Complications in surgery for Crohn's disease after preoperative antitumour necrosis factor therapy

BACKGROUND

The use of biological therapy (biologicals) is established in the treatment of Crohn's disease. This study aimed to determine whether preoperative treatment with biologicals is associated with an increased rate of complications following surgery for Crohn's disease with intestinal anastomosis.

METHODS

All patients receiving biologicals and undergoing abdominal surgery with anastomosis or strictureplasty were identified at six tertiary referral centres. Demographic data, and preoperative, operative and postoperative details were registered. Patients who were treated with biologicals within 2 months before surgery were compared with a control group who were not. Postoperative complications were classified according to anastomotic, infectious or other complications, and graded according to the Clavien-Dindo classification.

RESULTS

Some 111 patients treated with biologicals within 2 months before surgery were compared with 187 patients in the control group. The groups were well matched. There were no differences between the treatment and control groups in the rate of complications of any type (34·2 versus 28·9 per cent respectively; P = 0·402), anastomotic complications (7·2 versus 8·0 per cent; P = 0·976) and non-anastomotic infectious complications (16·2 versus 13·9 per cent; P = 0·586). In univariable regression analysis, biologicals were not associated with an increased risk of any complication (odds ratio (OR) 1·33, 95 per cent confidence interval 0·81 to 2·20), anastomotic complication (OR 0·89, 0·37 to 2·17) or infectious complication (OR 1·09, 0·62 to 1·91).

CONCLUSION

Treatment with biologicals within 2 months of surgery for Crohn's disease with intestinal anastomosis was not associated with an increased risk of complications.

Restorative proctocolectomy in patients with ulcerative colitis: a cross-sectional Danish population study on function and quality of life

AIM

The study evaluated function and quality of life (QoL) in all patients having restorative proctocolectomy (RPC) in Denmark for ulcerative colitis (UC) from 1980 to 2010. Inclusion of all patients in one country has never previously been achieved.

METHOD

All patients who had had a RPC in Denmark, from the first case in 1980 to the last case in 2010, were studied. A cross-sectional questionnaire survey was performed, and function and QoL were assessed using a standardized questionnaire - the Short-Form 36 (SF36) - and the inflammatory bowel disease questionnaire (IBDQ).

RESULTS

The median duration of follow up was 11 (range, 1-30) years. Apart from deaths, pouch failures and research protection, data on function and QoL were obtained from 1047 (85%) of 1229 patients who had a functioning pouch at the time of the investigation. More female patients than male patients experienced urgency (56% vs 44%, P = 0.0021). The median number of bowel movements per 24 h was 7 (range, 1-23) in female patients and 6 (range, 1-20) in male patients (P < 0.001). Pad usage was more frequent among female patients than among male patients (62% vs 38%, P < 0.001). A higher incidence of major incontinence (P = 0.009) and use of pads (P = 0.01) was found among patients who had been operated on 21-30 years previously compared with those operated on 11-20 years previously. The prevalence of urgency was higher in patients who received surgery 0-10 years previously compared with 11-20 years previously (P = 0.009). The total IBDQ score was higher in male patients than in female patients (P < 0.001). Male patients scored higher in five of eight SF36 domains (P < 0.001).

CONCLUSION

Female patients had more urgency, a higher frequency of defaecation and higher pad usage. This was associated with a reduced QoL. Nevertheless, RPC resulted in good function and a high degree of satisfaction in most patients.

Clinical and proctoscopic evaluation of topical formalin application in the treatment of chronic radiation proctitis

BACKGROUND AND AIMS

Chronic radiation proctitis is a disease associated with radiotherapy of cancer in the pelvic region. The main symptom is rectal bleeding. Several treatment modalities have been attempted, but few have demonstrated satisfactory effects. We present our experience with formalin applied locally to the rectal mucosa in the treatment of chronic radiation proctitis. Furthermore, we assess possible complications, the gravest suggested being cancer. Previous studies on the subject have reported good results, but often with a somewhat vaguely defined follow-up. Our evaluation of the treatment was based on both subjective symptoms and proctoscopic findings.

MATERIAL AND METHODS

A small study (N = 11) was conducted retrospectively. All patients treated for chronic radiation proctitis with formalin in our clinic were identified, and data concerning effect and complications were collected by studying the patients' records, with a questionnaire and a follow-up interview and proctoscopy.

RESULTS

The study showed a marked decrease in bleeding and objective signs of proctitis in all patients. Complete cessation of bleeding was achieved in five patients. Possible complications to the treatment detected in our study were the following: anorectal pain, tenesmus, incontinence, diarrhea, and mucous rectal discharge. No signs of neoplasia were found.

CONCLUSIONS

The formalin treatment had a very good effect on chronic radiation proctitis. Possible complications were detected. Except in the case of anorectal pain, these are all of a questionable nature and can possibly be attributed to chronic radiation proctitis itself rather than the formalin treatment. Further study is warranted to confirm long-term effects of the formalin and to exclude possible complications, especially secondary anorectal cancer.

Low complication rate after stoma closure. Consultants attended 90% of the operations

AIM

To evaluate complications after stoma closure.

METHOD

Using a retrospective review of 997 medical records, data were collected from all patients undergoing stoma closure at the Department of Surgery P, Aarhus University Hospital, Denmark, from 1996 to 2010. Patient data after Hartmann reversal and loop-ileostomy closure were compared. Data regarding the grade of the operating surgeon and assistant were extracted.

RESULTS

Out of 997 patients, 700 (70.6%) had a loop-ileostomy closure and 172 (17.4%) had a Hartmann reversal. Postoperative mortality was 0.5%. Seven patients required re-operation (0.7%). Morbidity was registered in 31.9% of the patients, with 131 (13.1%) having early complications and 187 (18.8%) having late complications. Wound infection was the most frequent early complication, which occurred in 31 patients (3.1%). Only 10 patients (1%) had an anastomotic leak. Incisional hernia was the most frequent late complication, occurring in 92 patients (9.3%). A consultant attended 90% of the operations. Junior surgeons never performed stoma closure without supervision. Body mass index was significantly associated with the development of incisional hernia. Hartmann reversal was associated with higher rates of complications compared with loop-ileostomy closure. In patients with Hartmann reversal, stapled anastomosis was associated with stricture in 12 out of 95 cases (12.6%), whereas hand-sewn anastomosis was not associated with stricture (0 out of 64 patients; 0%; P < 0.05).

CONCLUSION

Stoma closure is associated with low rates of leakage. A favourable case mix and high degree of consultant attendance may explain the good results.

Ileostomy revision using noncutting linear stapler

OBJECTIVE

The study aimed to evaluate the outcome of ileostomy revision for retraction and prolapse using noncutting linear stapler.

METHOD

Forty five patients undergoing a total of 94 stapled revisions between 1.1.1995 and 31.12.2005 were identified by the unique code for stomal revision. Medical records for all patients were examined.

RESULTS

Thirty-five (77.8%) of the 45 patients were women. In 43 (95.6%), the indication was stomal retraction. Median follow-up was 28 months (2-122). One or more stapling procedures resulted in a normal stoma at follow-up in 18 (41.9%) of 43 patients treated for stomal retraction. When other types of repair were included, a normal stoma was achieved in 30 (69.8%) of 43 patients. Patients with a low BMI had the lowest success rate (44%), but none of the possible factors analysed for influence on success had a statistically significant impact. Two patients were treated for prolapse, and both needed other types of revision.

CONCLUSIONS

Stapled ileostomy revision is easy to perform and has a low morbidity. Less than half the patients achieve a satisfactory long-term result after one or more stapling procedures. Many patients still benefit from other types of revision when stapling has failed.

Diagnostic value of self-reported symptoms in Danish outpatients referred with symptoms consistent with colorectal cancer

OBJECTIVE

To assess the association between self-reported symptoms and a diagnosis of colorectal cancer (CRC) in symptomatic outpatients without CRC risk factors, defined by a Danish expert group.

METHOD

A cross-sectional study of patients aged 40 years and older referred by general practitioners to two Danish surgical outpatient clinics for symptoms consistent with CRC during a 16-month period. CRC was diagnosed at endoscopy and through follow up. Before their first appointment, participants completed a questionnaire about symptoms.

RESULTS

The study included 2172 patients. Of these, 122 were diagnosed with CRC (5.6%). Median age was 61 years (range: 40-97) and 44.0% were men. All symptoms had high (93.4-96.8%) negative predictive values for CRC. The highest positive predictive values (PPV) were found for dark rectal bleeding (PPV: 20.6%) and CRC was diagnosed in a first-degree relative over the age of 50 years (PPV: 11.2%). At multiple logistic regression analysis dark rectal blood was the most important predictor of CRC (OR: 7.4). Other predictors were age 60 years or older (OR: 3.0), change in frequency of bowel movements (OR: 2.5), CRC diagnosed in a first-degree relative over the age of 50 years (OR: 2.6), male gender (OR: 2.2) and mono-symptomatic fresh rectal blood (OR: 1.7).

CONCLUSION

No self-reported symptoms presented by outpatients without CRC risk factors can be used accurately to identify patients with CRC with certainty. For clinical purposes self-reported symptoms seems thus not to be a useful accurate tool to distinguish between symptomatic outpatients with and without CRC.

Endothelium-dependent responses in small human mesenteric arteries

The aim of the present study was to investigate the endothelial function in human mesenteric arteries with specific reference to defining the role of endothelium-derived nitric oxide (EDNO) and the endothelium-derived hyperpolarizing factor (EDHF). Isolated segments of small human mesenteric arteries (225-450 microm inner diameter) were mounted in organ baths for recording isometric tension. In arteries precontracted with U46619 (thromboxane A(2) analogue, 10(-7) M), endothelium-dependent relaxations were induced in a concentration-dependent manner by substance P and histamine. In normal Krebs solution the relaxations to substance P (10(-9) M) and histamine (10(-7) M) were not significantly affected by preincubation with N(omega)-nitro-L-arginine (L-NNA, 10(-4) M) or indomethacin (10(-5) M). When the preparations were exposed to a solution containing 60 mM KCl, stable contractions were induced, but relaxations could still be induced by substance P and histamine. When the arteries were further preincubated with L-NNA, the relaxations were almost abolished. A combination of apamin (3 x 10(-7) M) and charybdotoxin (10(-9) M) almost abolished relaxations in normal Krebs solution. It is concluded that isolated human mesenteric arteries respond to substance P and histamine with relaxations that are endothelium-dependent. Synthesis of both EDNO and EDHF seem important for these relaxations, whereas prostaglandins seem to be of minor importance.

Response, relapse and mucosal immune regulation after infliximab treatment in fistulating Crohn's disease

BACKGROUND

Infliximab reduces mucosal inflammation in some, but not all, patients with Crohn's disease.

AIM

To monitor clinical data and changes in mucosal cytokine levels after infliximab treatment to identify differences between responders and non-responders.

METHODS

Twenty-six patients with fistulating Crohn's disease received three infliximab infusions at weeks 0, 2 and 6. Follow-up was for 1 year and included clinical examination, colonoscopy, ano-rectal ultrasound and magnetic resonance imaging. Biopsies were taken at weeks 0, 8, 26 and 52. Cell cultures were established and analysed for tumour necrosis factor-alpha, interferon-gamma and interleukin-10 levels, and related to clinical status and fistula healing.

RESULTS

Eleven of 15 patients (73%) with active disease (Crohn's disease activity index > 150) obtained remission (Crohn's disease activity index < 150) at 8 weeks. In in vitro cell cultures, there was reduced tumour necrosis factor-alpha and interleukin-10 production at week 26, with the latter persistent throughout the study period. When the disease deteriorated or relapsed, there was increased interferon-gamma production in in vitro cell cultures. Fistula healing was associated with reduced production of interferon-gamma, tumour necrosis factor-alpha and interleukin-10.

CONCLUSIONS

Infliximab down-regulates mucosal immune activation in Crohn's disease. Monitoring of mucosal cytokine levels after infliximab treatment by whole biopsy cultures may be useful as interleukin-10, tumour necrosis factor-alpha and interferon-gamma production are different in responders and at relapse.

Surveillance of surgical training by detailed electronic registration of logical components

OBJECTIVE

To obtain detailed information about the degree of surgical trainee supervision and delegation of procedures in a subspecialised department.

DESIGN

Operative procedures and their logical components were recorded in a database constructed in Microsoft Access. Information about operating surgeon and assistants and their grade was registered prospectively over 12 months.

SUBJECTS AND METHODS

A total of 1250 intermediate or major procedures were performed by eight consultants, one staff specialist, four senior registrars, three specialist registrars, and five registrars.

MAIN MEASURE

Number of components performed by surgeons in each grade and the degree of supervision and delegation.

RESULTS

Eight hundred and eighty five of the operations were elective, while 365 were done as emergency procedures. Emergency procedures were far more often done by surgeons in training than by a staff surgeon, while the opposite was true for elective operations. Out of 323 elective operations done by surgeons in training, 189 were done under supervision (58.5%), while 119 out of 276 emergency operations done by surgeons in training were supervised (43.1%; p=0.0002). One hundred and twenty eight of 638 (20%) open abdominal operations were done by the most junior surgeons, and yet they closed 36% of all abdominal wounds. Although the most junior surgeons only served as operating surgeons in 39 of 334 bowel operations (12%), they constructed 24% of all stomas, and 20% of all anastomoses. Registrars and specialist registrars never constructed stomas or anastomoses without supervision.

CONCLUSION

Detailed information about individual and general training and supervision was achieved by a simple registration. Significant additional information was obtained about the extent of delegation of components compared with standard registration of operative procedures.

Excessive nodular hyperplasia of Brunner glands associated with gastric hypersecretion and lipomatous atrophy of the pancreas

The case of a 34-year-old woman complaining of diarrhoea and abdominal pain is presented. Contrast radiography and endoscopy showed multiple polypoid tumours in the second part of the duodenum. Moreover, a severe fatty infiltration of the pancreas was shown by magnetic resonance and computed tomography scans. Due to pain, pancreatoduodenectomy (Whipple operation) was performed, and subsequent histopathologic examinations showed excessive Brunner gland hyperplasia of the duodenum and severe lipomatous atrophy of the pancreas. The occurrence of these two rare conditions in one patient has not been described previously, and it is conceivable that the lipomatous atrophy and exocrine insufficiency of the pancreas may have caused a compensatory stimulation of the submucosal structures of the duodenum.

Effects of transmural field stimulation in isolated smooth muscle of human rectum and internal anal sphincter

Smooth muscle preparations from the circular muscle layer of the most distal rectum and the proximal and distal human internal anal sphincter (IAS) mounted in organ baths to record isometric tension developed spontaneous tension. Transmural electrical field stimulation (TMS) induced frequency- and impulse duration-dependent relaxations sensitive to tetrodotoxin in the stimulation range of 0.5-40 Hz and 0.04-0.6 ms. Poststimulus contractions were most frequent and prominent in rectal preparations. Maximal relaxations were comparable in the three locations and were achieved at 10 Hz and 0.4 ms. The frequency inducing half-maximal response was lower in rectal strips compared with IAS. Phentolamine (10-(6) M) enhanced relaxations and diminished off-contractions at 40 Hz in distal IAS. N omega-nitro-L-arginine (L-NNA) concentration dependently inhibited both relaxations and off-contractions (10 Hz, 0.4 ms). The pD2 values (-log EC50) of L-NNA were lower in rectal muscle compared with those in IAS. L-Arginine (10-(4) M) inhibited the blocking effect of L-NNA. In one-half of the preparations, L-NNA reversed the relaxations to duration contractions (15-40 Hz), which were inhibited by atropine in rectal preparations and by phentolamine in IAS. In conclusion, excitatory innervation of the IAS is alpha-adrenergic and cholinergic in the rectum. A product of the L-arginine-nitric oxide pathway mediates the TMS-induced inhibition of the muscle and is also involved in poststimulus contractions.

Transmitter interactions in rabbit internal anal sphincter

The aim of the present study was to investigate the relative importance of the different putative nonadrenergic noncholinergic (NANC) mediators and their interplay with cholinergic nerves in the rabbit internal anal sphincter (IAS). IAS preparations were mounted in organ baths for recording of isometric tension. Transmural field stimulation (TMS; 5-s trains; supramaximal voltage, 140-160 V; 0.4-ms impulse duration) was applied every 2 min with frequencies varying from 0.2 to 32 Hz. TMS induced frequency-dependent relaxations that amounted to 89.3 +/- 2.2% (n = 7). N omega-nitro-L-arginine (L-NNA; 10(-7)-10(-4) M; 8 Hz) reduced relaxations and this effect was partially inhibited by preincubation with L-arginine (10(-4) M). The effect of L-NNA was attenuated by atropine preincubation. Apamin (10(-6) M) shifted the frequency-response curve to the right but left maximal relaxations in response to TMS unaffected. In the presence of L-NNA (10(-4) M) and atropine (10(-6) M), the action (area between the frequency-response curve with or without a substance) of apamin was more pronounced, but, despite the presence of both L-NNA and apamin, some relaxation still remained. The frequency-response curve (control) was significantly shifted to the right by carbachol (10(-6) M). Concentration-response experiments showed that the response to exogenous nitric oxide (NO; 10(-7)-10(-4) M) was unaffected by carbachol (10(-6) M) preincubation, whereas responses to vasoactive intestinal polypeptide (VIP) and ATP were significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological identification of different inhibitory mediators involved in the innervation of the internal anal sphincter

1. Inhibitory non-adrenergic, non-cholinergic (NANC) responses were studied in isolated strips from the rabbit internal anal sphincter. 2. In the presence of atropine and guanethidine, transmural field stimulation induced frequency-dependent relaxations that reached a plateau at frequencies > or = 4 Hz. 3. These relaxations were inhibited by apamin (10(-6) M) and by N omega-nitro-L-arginine (L-NOARG, 10(-4) M). With these two substances in combination, relaxations were still seen in response to field stimulation, but only at frequencies > 2 Hz. 4. In the presence of both apamin (10(-6) M) and L-NOARG (10(-4) M), responses at high frequencies consisted of a fast relaxation followed by a slow return to prestimulus tension level. alpha-Chrymotrypsin hastens the return of tension to prestimulus level after high frequency stimulation. 5. Zinc-protoporphyrin IX, an inhibitor of haeme oxygenase, had a significant inhibitory effect on relaxations induced by transmural field stimulation. It was found, however, that responses to sodium nitroprusside and to isoprenaline (both 10(-9)-10(-4) M) were reduced comparably, indicating that the effect of zinc-protoporphyrin IX was unspecific. 6. It is concluded that pharmacological analysis allows identification of at least three distinguishable components of the inhibitory NANC innervation of the rabbit internal anal sphincter. The study does not allow conclusions about the role of carbon monoxide, a recently proposed mediator of NANC responses in opossum internal anal sphincter.

The role of the L-arginine-nitric oxide pathway for peristalsis in the opossum oesophageal body

BACKGROUND

The aim of the study was to determine the effect of NG-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide (NO) synthesis, on primary peristalsis in the oesophageal body.

METHODS

Peristalsis was induced by pharyngeal stroking in 14 lightly anaesthetized opossums. Oesophageal pressures were monitored with a four-channel, perfused catheter assembly and registered with external transducers 1, 4, 7, and 10 cm proximal to the oesophagogastric junction. Propagation time was the time taken for a contraction to travel between two recording sites and was determined in the proximal, middle, and distal parts of the oesophagus (propagation time between 10 and 7 cm, 7 and 4 cm, and 4 and 1 cm recording sites, respectively).

RESULTS

L-NNA (10(-7)-10(-5) mol/kg) dose-dependently reduced propagation time of the contraction in the distal oesophagus from 1.13 +/- 0.24 sec to 0.27 +/- 0.19 sec, whereas propagation in the proximal and middle parts of the oesophagus was unaffected. NG-nitro-D-arginine (D-NNA; 10(-5) mol/kg) had no influence on propagation time. In animals treated with L-NNA (10(-5) mol/kg) atropine (50 micrograms/kg) had no influence on propagation time in any part of the oesophagus. L-Arginine (10(-4) mol/kg) had no influence on the propagation time in animals treated with L-NNA (10(-5) mol/kg) and atropine (50 micrograms/kg). Neither D-NNA (10(-5) mol/kg) nor L-NNA (10(-7)-10(-5) mol/kg) influenced the amplitude of the contractions at any of the recording sites. In animals given L-NNA (10(-5) mol/kg) atropine (50 micrograms/kg) reduced the amplitude of the contraction significantly only at the distal recording site (1-cm recording site) from 62.0 +/- 4.9 mmHg to 34.5 +/- 5.3 mmHg. L-Arginine (10(-4) mol/kg) had no effect on the amplitude of contractions.

CONCLUSION

The L-arginine-NO pathway plays a role in the control of primary peristalsic contractions of the oesophagus.

Effects of transmural field stimulation in isolated muscle strips from rabbit sphincter of Oddi and duodenum

The purpose of the study was to compare the effect of transmural field stimulation (TMS) on isolated smooth muscle strips from rabbit sphincter of Oddi (SO), duodenal circular layer (Dc) and duodenal longitudinal layer (D1). The strips were suspended in thermostatically controlled 5-ml organ baths containing Krebs solution constantly bubbled with 5% CO2 in O2. TMS was delivered through platinum electrodes (140 V, 0.4 ms, 5 s trains, 40 Hz). The TMS responses could be divided in two main responses: (1) contraction initiated after cessation of the stimulus train, preceded by an inhibitory phase during TMS ('off'); and (2) contraction initiated during TMS ('duration'). The 'duration' response was observed in one out of 20 strips in the SO and Dc compartments, whereas 11 D1 strips (55%) showed 'duration' responses (P < 0.001). Atropine (10(-6)) converted all 'duration' responses to an 'off' response preceded by an inhibitory phase during TMS and reduced the contractile amplitudes with 40-65%. L-NNA significantly increased the number of 'duration' responses in all types of muscle, and caused a 40% increase in D1 contractile amplitude. Inhibitory responses could not be removed by atropine, propranolol and phentolamine. The results suggest that the intrinsic innervation of SO and duodenal muscle consists of a mixture of excitatory, cholinergic and inhibitory NANC pathways. The latter may utilize, wholly or partly, NO or a related compound as transmitter. A relative dominance of excitatory, cholinergic responses was present in the D1 strips, whereas inhibitory responses were dominating in the SO and Dc strips.

The role of the L-arginine/nitric oxide pathway for relaxation of the human lower oesophageal sphincter

Smooth muscle specimens were taken from the oesophagogastric junction (OGJ) in patients operated on for gastrointestinal malignancies not involving the OGJ. The smooth muscle bundles of the inner, circular layer of the OGJ were richly innervated by fine nerve fibres staining positively for NADPH diaphorase. The outer longitudinal layer had a markedly lower number of NADPH-diaphorase positive nerve fibres. When the preparations were suspended in organ baths for recording of isometric tension, they developed active tension. Transmural field stimulation (TMS) induced frequency-dependent relaxations, which were abolished by NG-nitro-L-arginine (L-NNA; 10(-4) M), and were often converted to atropine-sensitive contractions. The effect of L-NNA was concentration-dependent, and the concentration-response curve for L-NNA was shifted to the right by L-arginine pre-incubation. The enantiomer NG-nitro-D-arginine (10(-4) M) also showed inhibitory actions on the responses to TMS, but significantly less than L-NNA. Relaxant responses to vasoactive intestinal polypeptide (VIP), forskolin, and sodium nitroprusside were unaffected by L-NNA pre-incubation. Exposure to a 124 mM K+ solution resulted in a biphasic relaxation of the preparations. This relaxation was not seen in preparations treated with scorpion venom (20 micrograms ml-1) or L-NNA (10(-4) M). Instead, a contractile response to 124 mM K+ solution was found. The results suggest that NANC responses to electrical stimulation of nerves in the human OGJ are mediated by a product generated from L-arginine.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of the L-arginine/nitric oxide pathway in relaxation of isolated human penile cavernous tissue and circumflex veins

In human penile corpus cavernosum strips, pre-contracted by noradrenaline, electrical stimulation of nerves evoked non-adrenergic, non-cholinergic (NANC) relaxant responses which could be inhibited by tetrodotoxin 10(-6) M, NG-nitro-L-arginine (L-NNA) 10(-7)-10(-4) M, and oxyhaemoglobin 10(-5) M, but not by methylene blue (MB) 10(-5) M. Acetylcholine-induced relaxations were also inhibited by L-NNA 10(-4) M and oxyhaemoglobin 10(-5) M, but were unaffected by pyrogallol 10(-4) M, MB 10(-5) M, and tetrodotoxin 10(-6) M. MB 5 x 10(-4)-10(-4) M significantly reduced the responses to both electrical stimulation and to acetylcholine. Nitric oxide (NO) 10(-7)-10(-4) M and sodium nitroprusside 10(-9)-10(-4) M caused concentration-dependent relaxations. The NO-induced relaxations were inhibited by oxyhaemoglobin 10(-5) M, and the concentration-response curve for sodium nitroprusside was shifted to the right by MB 10(-5) M. The response to sodium nitroprusside was unaffected by L-NNA 10(-4) M, oxyhaemoglobin 10(-5) M, and pyrogallol 10(-4) M. In circumflex veins, pre-contracted by noradrenaline, no NANC-mediated relaxation was found in response to electrical stimulation; acetylcholine caused endothelium-dependent relaxations, which were insensitive to L-NNA 10(-4) M and oxyhaemoglobin 10(-5) M. NO and sodium nitroprusside caused concentration-dependent relaxations; the concentration-response curves for NO and sodium nitroprusside were shifted to the right by oxyhaemoglobin 10(-5) M. Removal of the endothelium left the NO- and sodium nitroprusside-induced relaxations unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanical properties of isolated smooth muscle from human rectum and internal anal sphincter

The passive and active length-tension relations of the circular smooth muscle layer of the human distal rectum and the proximal and distal internal anal sphincter were investigated. Muscle strips were prepared and mounted in organ baths for recording of isometric tension. Resting lengths (LR) were measured, and the preparations were elongated stepwise. At each length, the corresponding values for passive tension, spontaneous active resting tension, and the submaximal active tension were recorded. Elongations of 200-380% of LR were possible before a sharp increase in passive tension occurred. None of the mean tension values measured at length for maximal active tension (LO) differed significantly among the three muscle types. All strips developed active resting tension. This tension was myogenic and contributed 10 +/- 3, 23 +/- 6, and 27 +/- 6% to the total active performance of rectal and proximal and distal sphincter preparations, respectively. Collagen constituted approximately 50% of smooth muscle biopsies, with highest contents in distal internal anal sphincter. This study provides an acceptable method for assessing the optimal experimental length by stretching the strips in an inactive state to 200% of LR, followed by individual adjustment of the passive tension to 5 mN/mm2 measured at 200% of LR.

[The role of nitrogen oxide synthesis for relaxation of the internal anal sphincter]

The purpose of the present study was to examine the role of the L-arginine-nitric-oxide pathway in neurogenic relaxation of the internal anal sphincter. Muscle strips representing the internal anal sphincter were prepared from 17 adult opossums. The preparations were mounted in organ baths for recording of isometetric tension. N omega-nitro-L-arginine, an agent known to inhibit the L-arginine-nitric oxide pathway, concentration-dependently reduced relaxation induced by transmural field stimulation. At the highest concentration of N omega-nitro-L-arginine (10(-4) M), no relaxation was evoked at any frequency tested (0.5-40 Hz). The inhibitory response to exogenous VIP was unaffected by N omega-nitro-L-arginine pretreatment, indicating that VIP relaxation does not utilize the L-argining-nitric oxide pathway. It is concluded that the non-adrenergic, non-cholinergic innervation of the internal anal sphincter involves an inhibitory substance generated from the L-arginine--No pathway. Whether this substance is nitric oxide or a related nitroso compound remains to be settled.

Mechanical effects of some prostanoids on isolated human oesophageal submucosal veins

The effects of prostaglandins E1, E2, F2 alpha, prostacyclin, and the thromboxane A2-mimic U46619 were investigated on isolated human oesophageal submucosal veins from the oesophageal body and the oesophagogastric junction. U46619 most potently, but also PGF2 alpha produced venocontraction without differences between preparations from the oesophageal body and the oesophagogastric junction. PGE1 and prostacyclin caused relaxation of vessels precontracted with U46619 (10(-9) M). PGE2 induced either contraction or relaxation, but biphasic effects in the same vessel segment were not seen. Indomethacin 10(-6) M inhibited the contractile responses to both noradrenaline and K+ (124 mM), suggesting that the agonists induced synthesis or release of vasoconstrictor prostanoids. Prostanoids exert potent mechanical effects in submucosal oesophageal veins and may be of physiological importance.

A possible role of the L-arginine-nitric oxide pathway in the modulation of cholinergic transmission in the guinea-pig taenia coli

1. The role of the L-arginine-nitric oxide (NO) pathway for non-adrenergic, non-cholinergic (NANC) relaxation of the guinea-pig taenia coli was studied by recording isometric tension in response to transmural field stimulation (TMS). 2. In preparations precontracted with prostaglandin F2 alpha (PGF2 alpha, 10(-6) M), TMS induced frequency-dependent responses of the muscle strips which could be abolished by tetrodotoxin (10(-6) M). NG-nitro-L-arginine (L-NNA, 10(-4) M), an L-arginine analogue, and potent inhibitor of NO synthesis, stereospecifically inhibited maximum relaxations, but did not shift the frequency-response curve. Pre-incubation with NG-nitro-D-arginine (D-NNA, 10(-4) M), atropine (10(-6) M) plus L-NNA (10(-4) M), or atropine (10(-6) M) alone, had no influence on the frequency-response characteristics. 3. L-NNA (10(-7)-10(-4) M) concentration-dependently inhibited relaxations in PGF2 alpha (10(-6) M) precontracted strips in response to TMS, but did not abolish relaxations. Preincubation with L-arginine (10(-4) M) inhibited these effects of L-NNA. L-NNA (10(-4) M) had no effect on the inhibitory response during TMS in strips preincubated with atropine (10(-6) M). 4. The relaxation induced by sodium nitroprusside and forskolin (10(-9)-10(-4) M) was not influenced by L-NNA (10(-4) M) preincubation as expressed by identical pD2 and Emax values. 5. Contractions induced by PGF2 alpha (10(-9)-10(-4) M) and carbachol (10(-9)-10(-4) M) were not affected by pretreatment with L-NNA (10(-4) M), was expressed by identical pD2 and Emax values. 5. Contractions induced by PGFA (10-1- 10-4M) and carbachol (10-1 0-4 M) were not affected by pretreatment with L-NNA (10-4 M), as expressed by identical pD2 and Em. values.6. In conclusion, the L-arginine-NO pathway seems to play a role in the NANC innervation of the guinea-pig taenia coli. The inhibitory effect of NO or a NO-like compound depends on the integrity of the cholinergic pathways and it is proposed that this compound exerts its effects prejunctionally on cholinergic nerves, by inhibiting the release of acetylcholine.

Biomechanical wall properties and collagen content in the partially obstructed opossum esophagus

A specially designed probe was used to investigate biomechanical wall properties of the esophagus in opossums with distal esophageal banding. A balloon was stepwise inflated and deflated 6 cm above the lower esophageal sphincter before the banding and at 2 weeks postoperatively. After animals were killed, collagen content of the esophageal wall was determined. Preoperatively, cross-sectional area and wall tension at maximal inflation of the balloon, compliance, and hysteresis were 108.04 +/- 7.23 mm2, 5.8 +/- 0.3 cm H2O/m, 0.664 +/- 0.081 mm2/cm H2O, and 101.14 +/- 18.89 mm2, respectively. Postoperatively, the parameters increased to 357.45 +/- 54.22 mm2 (P < 0.001), 10.5 +/- 1.4 cm H2O/m (P < 0.001), 2.402 +/- 0.420 mm2/cm H2O (P < 0.001), and 225.86 +/- 44.56 mm2 (P < 0.05), respectively. The collagen content was 0.065 +/- 0.004 and 0.104 +/- 0.009 mg/mg dry defatted weight in the mid and distal normal esophagus, respectively, compared with 0.110 +/- 0.012 and 0.121 +/- 0.012 mg/mg in the banded group (P < 0.05 in the middle part). A positive correlation was shown between the maximal cross-sectional area and the collagen content in the mid-esophagus (P < 0.05). In conclusion, biomechanical wall properties were altered significantly, indicating dilatation and decreased ability of the esophageal wall to resist intraluminal pressure.

Effects of prostanoids and indomethacin on isolated smooth muscle from the human lower oesophagus

Smooth muscle strips representing the longitudinal and the circular muscle layers of the oesophageal body and the oesophagogastric junction of the human oesophagus were mounted in organ baths and isometric tension recorded. Transmural field stimulation was applied to strips from both layers of the oesophageal body and to strips from the longitudinal muscle layer of the oesophagogastric junction. This resulted in contractions after cessation of the stimulus train in circular muscle, and in contractions during stimulation in longitudinal muscle preparations. Indomethacin lowered active tension in strips from the circular muscle layer of the oesophagogastric junction, and decreased responses to transmural field stimulation in all strips from the longitudinal muscle layer. The response to transmural field stimulation was increased in strips from the circular muscle layer of the oesophageal body, suggesting an inhibitory function of endogenous prostanoids in this muscle layer. Prostaglandin (PG) F2 alpha and the thromboxane A2 mimic U-46619 increased the responses to transmural field stimulation in all muscle types and the active tension in circular muscle from the oesophagogastric junction. PGE1 and PGE2 increased the responses to transmural field stimulation strips from the longitudinal muscle layer. In circular muscle strips from the oesophageal body responses to transmural field stimulation were inhibited. PGE1 decreased active tension in circular muscle strips from the oesophagogastric junction, whereas PGE2 produced inconsistent effects. These results suggest a role of prostanoids in the regulation of neuromuscular function in the human lower oesophagus. Moreover, exogenous prostaglandins may modulate oesophageal motor function.

Action profiles of nitric oxide, S-nitroso-L-cysteine, SNP, and NANC responses in opossum lower esophageal sphincter

Circular muscle strips from opossum lower esophageal sphincter were suspended in organ baths for measurement of isometric tension. Nonadrenergic noncholinergic (NANC) inhibitory nerves were stimulated by means of transmural field stimulation. This induced frequency-dependent relaxations of the muscle strips. Methylene blue (3 x 10(-6) M; inhibits guanylate cyclase) and pyrogallol (10(-4) M; generates superoxide anions) had no influence on relaxations, whereas oxyhemoglobin [10(-5) M; binds nitric oxide (NO) and other nitroso compounds extracellularly] inhibited relaxations at all frequencies. NO concentration dependently relaxed the muscle strips. Pyrogallol (10(-4) M) and methylene blue (3 x 10(-6) M) inhibited and oxyhemoglobin (10(-5) M) nearly abolished relaxation induced by NO. S-nitroso-L-cysteine caused concentration-dependent relaxations of the muscle strips, which were inhibited by pyrogallol (10(-4) M), whereas methylene blue (3 x 10(-6) M) augmented the action of S-nitroso-L-cysteine. Methylene blue (3 x 10(-6) M) had no influence on the concentration-dependent relaxations caused by sodium nitroprusside (SNP). Oxyhemoglobin (10(-5) M), and to a lesser extent pyrogallol (10(-4) M), both inhibited the effects of SNP. The action profiles for S-nitroso-L-cysteine, NO, and SNP differed from the action profile for NANC nerve-mediated response. Although pyrogallol inhibited the effects of SNP, the action profile generally resembled the action profile for NANC responses more closely than did the profiles for S-nitroso-L-cysteine or NO. In conclusion, of the nitroso compounds studied, SNP most closely resembled the response to NANC nerve stimulation. Neither NO nor S-nitroso-L-cysteine individually mimicked the NANC response.

Involvement of the L-arginine-nitric oxide pathway in internal anal sphincter relaxation

The purpose of this study was to examine the role of the L-arginine-nitric oxide pathway in neurogenic relaxation of the internal anal sphincter. Muscle strips representing the internal anal sphincter were prepared from 17 adult opossums. The preparations were mounted in organ baths for recording of isometric tension. N omega-nitro-L-arginine, an agent known to inhibit the L-arginine-nitric oxide pathway, concentration-dependently reduced relaxations induced by transmural field stimulation. At the highest concentration of N omega-nitro-L-arginine (10(-4) mol/L), no relaxation was evoked at any frequency tested (0.5-40 Hz). The inhibitory response to exogenous vasoactive intestinal polypeptide was unaffected by N omega-nitro-L-arginine pretreatment, indicating that vasoactive intestinal polypeptide relaxation does not use the L-arginine-nitric oxide pathway. In addition, responses to forskolin and sodium nitroprusside were not influenced by N omega-nitro-L-arginine preincubation, suggesting that the effect observed was not caused by a direct influence on the adenylate or the guanylate cyclases. It is concluded that the nonadrenergic, noncholinergic innervation of the internal anal sphincter involves an inhibitory substance generated from the L-arginine-nitric oxide pathway. Whether this substance is nitric oxide or a related nitroso compound remains to be settled.

Electrically-induced, nerve-mediated relaxation of rabbit urethra involves nitric oxide

Isolated smooth muscle preparations from the rabbit urethra precontracted with noradrenaline (10(-5) M), endothelin (10(-7) M), or arginine vasopressin (10(-7) M) responded to electrical field stimulation by frequency-dependent non-adrenergic, non-cholinergic relaxations, which could be blocked by tetrodotoxin (10(-6) M). Relaxation was more pronounced in preparations precontracted by endothelin than by noradrenaline or arginine vasopressin. The electrically induced relaxations were reduced in a concentration-dependent manner by pretreatment for 30 minutes with NG-nitro-L-arginine (10(-6) to 10(-4) M) and NG-monomethyl-L-arginine (10(-5) to 10(-4) M). At the highest concentration of NG-nitro-L-arginine used (10(-4) M), relaxation was abolished and/or changed into a contraction. The effect of NG-nitro-L-arginine was reversible. NG-nitro-D-arginine had no effect. Pretreatment for 30 minutes with L-arginine (10(-3) M) slightly, but significantly, enhanced the maximum relaxation to field stimulation in noradrenaline-precontracted preparations. L-arginine pretreatment also prevented the effects of low, but not high, concentrations of NG-nitro-L-arginine. In contrast, D-arginine had no effect. Electrically induced relaxations were not significantly affected by methylene blue (10(-5) M) or superoxide dismutase (20 U/ml). Addition of nitric oxide (present in acidified solution of NaNO2) caused transient and concentration-dependent relaxations in preparations precontracted by noradrenaline. At the maximum concentration used (10(-3) M), the relaxant response averaged 67% of the tension induced by noradrenaline. Nitric-oxide-induced relaxations were not affected by NG-nitro-L-arginine or L-arginine, but were significantly inhibited by methylene blue. In preliminary experiments, effects similar to those found in rabbit urethra were also observed in isolated urethral preparations obtained from three patients. It is suggested that in the urethra, nitric oxide is involved in the mediation of relaxation evoked by electrical stimulation of nerves.

The role of the L-arginine-nitric oxide pathway in relaxation of the opossum lower oesophageal sphincter

1. The role of the L-arginine-nitric oxide pathway in lower oesophageal sphincter (LOS) relaxation and oesophageal peristalsis was investigated. 2. Twenty four adult opossums were anaesthetized and the right vagus nerve was isolated in the neck and sectioned. Electrical stimulation, applied to the peripheral end of the nerve, resulted in a frequency-dependent relaxation of the LOS, and peristaltic and non-peristaltic contractions in the oesophageal body. 3. N omega-nitro-L-arginine (L-NNA, 10(-8)-10(-5) mol kg-1), an inhibitor of the L-arginine-nitric oxide pathway, inhibited LOS relaxation in a dose-dependent manner, but did not affect resting LOS pressure. At the highest dose of L-NNA no relaxation of the LOS was elicited in response to vagal stimulation. The effect of L-NNA, (10(-5) mol kg-1) was fully reversed by infusion of 10(-4) mol kg-1 L-arginine. Peristaltic velocity and amplitude of contractions in the oesophageal body were unaffected by L-NNA. 4. Infusion of sodium nitroprusside reduced LOS pressure to zero, and the drug was equally potent in control animals (-log ED50:8.1 +/- 0.2 mol kg-1) and in animals pretreated with L-NNA (-log ED50:8.2 +/- 0.3 mol kg-1). This suggests that the effect of L-NNA was not directly on guanylate cyclase. 5. A significant elevation of blood pressure was recorded after administration of L-NNA (10(-5) mol kg-1). 6. It is suggested that the L-arginine-nitric oxide pathway plays an important functional role for relaxation of the LOS, but not for oesophageal peristalsis. Whether the active substance is nitric oxide or a related nitroso-compound remains to be settled.

Motility regulating effects of galanin on smooth muscle of porcine ileum

We studied the effect of synthetic porcine galanin on circular and longitudinal oriented strips of pig ileal muscle. Galanin 10(-11)-10(-6) M had no effect on resting tension in the two layers. In circular muscle precontracted with carbachol 10(-6) M, galanin dose-dependently inhibited the amplitude of contractions to a maximum of 33 +/- 8% at 10(-6) M. In longitudinal muscle the amplitude of contractions induced by carbachol 10(-7) M or transmural field stimulation increased after addition of galanin 10(-9)-10(-7) M to a maximum of 21 +/- 6%, while at higher concentrations inhibition occurred. Maximal inhibition was 36 +/- 14% at galanin 10(-6) M. Tetrodotoxin did not influence the effects of galanin in the preparations. The results indicate that in the homologous species galanin inhibits the circular muscle layer, possibly by a direct action on the smooth muscle. In the longitudinal muscle the effect of galanin is apparently excitatory. The inhibition observed with high concentration of galanin could be due to tachyphylaxis and desensitization. Alternatively, an additional population of low affinity, inhibitory receptors may exist.

Mechanical properties of isolated human oesophageal submucosal veins

The mechanical properties of isolated human oesophageal submucosal veins were investigated. The veins were without tone or spontaneous activity and possessed a high compliance, tolerating a stretch of several hundred per cent of the length at which the vessels were first able to contract with only minor increases in passive tension. The veins were capable of producing active tension when the length exceeded 30% of L0 (the length at which maximum wall tension (T0) was developed when activated by 124 mM K(+)-solution). The veins from the oesophageal body (OB) had a higher L0 than the veins from the gastrooesophageal junction (GOJ) (1180 microns vs 820 microns) and T0 was correspondingly higher (1.1 mN/mm vs. 0.6 mN/mm). However, there was no significant difference in the calculated effective transmural pressure (P) at the two locations. Noradrenaline induced contractions in all preparations tested with a maximum response equivalent to the tension achieved after stimulation with 124 mM K(+)-solution, pD2 values for noradrenaline in vessels from the oesophageal body and the gastroesophageal junction were 7.03 +/- 0.28 (mean +/- SEM) and 7.15 +/- 0.20, respectively. The present model seems suitable for future studies of human oesophageal submucosal veins from the oesophageal body and the gastrooesophageal junction.

Mechanical properties of isolated smooth muscle from rabbit sphincter of Oddi and duodenum

Isolated smooth muscle from rabbit sphincter of Oddi (SO) and duodenum were mounted in organ baths. The SO strips were obtained as transversal strips from the midsection of the SO. The duodenal strips were prepared as longitudinal (Dl) or circumferential (Dc) strips. Resting length was defined. Carbachol was used for activation of the contractile apparatus. By repeatedly increasing the length of the strips by 20% of the resting length and recording values of resting and active tension, length-tension relations for each muscle type were constructed. None of the strips developed active resting tension. Twelve of the Dl strips (75%) developed spontaneous contractions versus four of the Dc strips (10%) and one of the SO strips. The strips eventually reached a length (Lo) at which further elongation gave no additional increase in active tension development. The Lo from the Dc strips differed significantly from SO Lo (p greater than 0.02) and Dl Lo (p less than 0.02), indicating structural differences. SO Lo and Dl Lo did not differ significantly. Differential extension of these tissues should be applied in future experiments on smooth muscles from this area.

Nitric oxide mediating NANC inhibition in opossum lower esophageal sphincter

Strips from opossum lower esophageal sphincter were prepared and mounted in organ baths for recording of isometric tension. Nonadrenergic, non-cholinergic (NANC) inhibitory responses were evoked by transmural field stimulation. The relaxant responses to field stimulation were inhibited in a concentration-dependent manner by N omega-nitro-L-arginine (L-NNA), a substance known to inhibit the formation of nitric oxide (NO). At a concentration at 10(-4) M of L-NNA, most preparations contracted during field stimulation, and this response was abolished by atropine (10(-6) M). L-Arginine (10(-5) M) shifted the concentration-response curve for L-NNA to the right. Relaxant responses to VIP (10(-9) to 10(-6)M) and sodium nitroprusside (10(-9) to 10(-5) M) were unaffected by preincubation with L-NNA (10(-5) to 10(-4) M) or L-arginine (10(-5) M). The inhibition of NANC-relaxation was apparently not due to an influence on release of a NANC transmitter different from NO, since L-NNA had no preserving effects on responses to field stimulation in preparations treated with scorpion venom. We conclude that involvement of a NO-generating process from L-arginine seems mandatory for NANC responses in the isolated lower esophageal sphincter.

Importance of the L-arginine-nitric oxide pathway in NANC nerve function of the opossum esophageal body

Circular muscle strips from the opossum esophageal body obtained 3-5 cm above the esophagogastric junction were suspended in organ baths for measurement of isometric tension. Stimulation of nonadrenergic, noncholinergic (NANC) inhibitory nerves was performed using transmural field stimulation (TMS). During TMS, no mechanical response was elicited. After cessation of the stimulus a short period, also without mechanical response, intervened, and this period is called latency. The latency was followed by the 'off'-contraction. In control preparations, the latency and the amplitude of the 'off'-contraction were 1.47 +/- 0.17 s, and 3.8 +/- 0.9 mN, respectively. The inhibitor of the L-arginine-nitric oxide (NO) pathway, NG-nitro-L-arginine (L-NNA) concentration-dependently reduced the latency at concentrations greater than 10(-6) M (n = 6-7). At the highest concentration of L-NNA (10(-4) M), 'off' contractions were no longer seen. In 5 out of 7 preparations exposed to L-NNA (10(-4) M), a small contraction was seen during stimulation, and this contraction was abolished by atropine (10(-6) M) in all strips. L-NNA concentration-dependently reduced the amplitude of contractions at concentrations greater than 10(-6) M (n = 6-7). At 10(-4) M, the amplitude was reduced to 3 +/- 2% of that of the initial contraction. Preincubation with L-arginine (10(-5) M) had no influence on the latency. The effects of L-NNA on both latency and the amplitude of contraction were antagonized by preincubation with L-arginine (10(-5) M). Atropine (10(-6) M had no effect on the amplitude of the 'off'-contraction in control preparations.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of esophageal achalasia]

Achalasia is a motor disease of the oesophagus which can be treated surgically (myotomy), medically or by dilatation. After myotomy satisfactory results are obtained in 84%-95% of the patients. Unacceptable results are due primarily to gastro-oesophageal reflux, inadequate or healed myotomy. Dilatation provide good results in about 70% but generally repeated dilatation is required. The remaining 30% can usually be treated surgically. Dilatation is complicated by perforation in about 3% of the patients, but reflux is not as frequent as after myotomy. At present medical treatment is only indicated temporarily prior to dilatation or surgery. Surgical treatment is recommended for patients with contemporary delayed gastric emptying, hiatal hernia, vigorous achalasia, epiphrenic diverticula and for children with achalasia. For the remaining patients both methods can be used but after 2-3 dilatations myotomy is recommended.

The actions of some beta-receptor agonists and xanthines on isolated muscle strips from the human oesophago-gastric junction

Isolated preparations from the circular muscle layer of the human oesophago-gastric junction were mounted in organ baths and isometric tension recorded. During an equilibration period, active resting tension developed suggesting that the preparations were representing the lower oesophageal sphincter. Active tension was abolished by exposing the preparations to Ca(++)-free medium. The two xanthines theophylline and enprofylline almost equipotently relaxed the preparations in a concentration-dependent manner (10(-7)-10(-3) M). Within therapeutic concentrations, theophylline inhibited active resting tension by 30-60%, while enprofylline lowered tension by less than 20%. Inhibitory actions of adenosine were demonstrated, and this suggests that adenosine antagonism is not the mechanism of action for xanthines in the oesophagus. Non-selective beta-receptor stimulation with isoprenaline inhibited active tension by 70% (10(-7) M), while beta 2-receptor stimulation with terbutaline inhibited tension by 47% (10(-5) M). Dobutamine, believed to preferentially stimulate beta 1-receptors, inhibited active tension in a concentration-dependent manner (10(-7)-10(-4) M). Metoprolol (10(-6) M), a selective beta 1-receptor antagonist, shifted the concentration-response curve for isoprenaline to the right, but left the maximal response unchanged. It is concluded that xanthines and beta-receptor agonists have inhibitory actions on circular muscle from the human oesophagogastric junction. The experimental data suggest the presence of beta 1- as well as beta 2-receptors, both mediating inhibition of active resting tension.

Mechanical properties of isolated human esophageal smooth muscle

Isolated smooth muscle strips from the human esophagus representing both the longitudinal and circular layers of the esophagogastric junction and the esophageal body were prepared. The strips were mounted in organ baths, and resting length was defined. By repeatedly increasing the length of the strips with 20% of resting length and recording values of resting and active tensions, length-tension relations for each muscle type were constructed. Only circular strips from the esophagogastric junction developed active, resting tension, disclosed by replacing the normal Ca2(+)-containing Krebs solution with Ca2(+)-free medium. Carbachol (10(-6) M) was used for submaximal activation of the contractile apparatus. At lengths between 180 and 260% of resting length, all strips reached optimum length (LO) where further elongation gave no further increase in active tension development. Repeated stimulations with carbachol was possible at a length of 200% of LO without affecting reproducibility. Determination of different collagen components revealed no differences between muscle types.

Effects of transmural field stimulation in isolated muscle strips from human esophagus

Smooth muscle strips representing longitudinal and circular muscle layers of the esophagogastric junction (EGJ) and esophageal body (EB) of the human esophagus were prepared. The strips were mounted in organ baths and isometric tension was recorded. Square wave stimulation was applied through platinum electrodes. Only responses abolished by tetrodotoxin (TTX) were considered neurogenic. Strips taken from longitudinal muscle layers of the EB and EGJ contracted during field stimulation. The responses evoked were abolished by atropine, and optimal frequency of stimulation was 40 Hz. In strips taken from the circular muscle layer of the EB, a contraction occurred after cessation of the stimulus. Atropine inhibited 90% of this response; the optimal stimulation frequency was 40 Hz. When a tone was induced in strips from this layer, a TTX-sensitive relaxation was seen during field stimulation. During stimulation of strips from the EGJ circular muscle layer, which was the only preparation developing spontaneous active tone, a relaxation was seen. A small contraction followed after termination of the stimulus. The relaxation, which was nonadrenergic, noncholinergic, reached maximum at 10 Hz. Atropine inhibited 40% of the contraction. The results suggest that in the longitudinal muscle layer of the human lower esophagus field stimulation causes postganglionic nerves to release transmitter(s) acting on muscarinic receptors. The responses of circular muscle layers seem to be mediated through release of at least two transmitters.

Eosinophil infiltration in primary esophageal achalasia. A possible pathogenic role

Smooth-muscle specimens from the lower esophagus of nine patients operated on for esophageal achalasia were examined with routine hematoxylin-eosin staining. This procedure revealed only a few eosinophils in or between the external smooth-muscle layers. Using specific immunohistochemical methods for the detection of the eosinophil cationic protein (ECP), however, varying degrees of eosinophil infiltration and extracellular deposit of ECP were disclosed in the achalasia specimens. The ECP also reacted with the monoclonal antibody, EG2, indicating secretion of the cytotoxic ECP. Few or no eosinophils were seen in the muscularis externa in specimens from six control patients without esophageal disease. In two controls many eosinophils were observed in the muscularis externa. However, no extracellular ECP was detected and very few eosinophils reacted with the monoclonal antibody (EG2), suggesting that these eosinophils were not activated. Depletion or total absence of peptidergic innervation was seen in all achalasia specimens but not in controls. Since the eosinophil cationic protein (ECP), in its activated form, is cytotoxic, we propose a pathogenic role of the eosinophil infiltration in achalasia.

The effect of a new selective alpha 2-adrenoreceptor antagonist, idazoxan, and the agonist, clonidine, on fasting antroduodenal motility in healthy volunteers

Studies were carried out on 16 healthy male volunteers to investigate whether intravenous administration of the alpha 2-adrenoreceptor antagonist, idazoxan, could affect fasting antroduodenal motility with and without administration of the agonist, clonidine. Contractile activity was recorded using an oral tube with perfused side holes positioned in the stomach and duodenum. Clonidine decreased antral contractile activity, an effect that idazoxan did not restore. Idazoxan alone did not affect antral motility. In the duodenum, clonidine decreased the number of contractions significantly and idazoxan restored them. Idazoxan alone did not increase duodenal motility but clonidine induced phase-III activity within the first 15 min after administration. The observations indicate that regulation of antroduodenal motility is influenced by alpha 2-adrenoreceptor drugs. Idazoxan may have potential as a motility restoring drug, for example, in postoperative ileus.

Fetal weight estimation in twin pregnancies

In this study the fetal weight was estimated by ultrasound measurements of the biparietal (BPD) and abdominal diameters (AD) in 154 consecutive twin pregnancies. In 80 twins an attempt to estimate fetal weight was made 0-4 days before delivery (26% of all twins examined). In 84% (67 infants) it was possible to estimate the fetal weight using the formula (0.0108 X AD1.72 X BPD0.99). 60% of the birth weights deviated less than 10% from the estimated fetal weight and 83% deviated less than 15%. The prediction error was nearly constant, expressed as percent of actual weight in the different weight groups (8.5-9.8%). In 19 LGA infants, 69% of the birth weights deviated less than 10% from the estimated fetal weight and 70% deviated less than 15%.

Severe destruction of esophageal nerves in a patient with achalasia secondary to gastric cancer. A possible role of eosinophil neurotoxic proteins

We present a case of secondary achalasia due to an adenocarcinoma of the stomach with no tumor infiltration of the esophagus. Immunohistochemical staining revealed a massive infiltration of activated eosinophils in the muscularis of the esophagus with secretion of the highly cytotoxic and neurotoxic eosinophil cationic protein (ECP). Immunohistochemical staining for the neuropeptides VIP and substance P, as well as the histochemical demonstration of AChE, revealed a nearly total absence of all three neurotransmitters/modulators compared to control. The hypothesis is advanced that eosinophil neurotoxicity is the cause of secondary achalasia.

Detection of gastro-oesophageal reflux disease. The clinical value of a barium examination after food stimulation

In a prospective study a barium examination combined with food stimulation was compared with the acid reflux test in 30 consecutive patients with symptoms of gastro-oesophageal reflux. Both methods were further compared with endoscopy and histology. Gastro-oesophageal reflux could be demonstrated by the radiologic examination in 22 patients and by the acid reflux test in 23 patients. By combining the two methods gastro-oesophageal reflux could be demonstrated in 27 patients. Comparing the two methods with symptoms, endoscopy, and histology they seemed to be of equal value. Accordingly, a food-stimulated barium examination is recommended as the first method for demonstrating gastro-oesophageal reflux because it is simple and well-tolerated by the patient.