Self-reported management among people with rotator cuff related shoulder pain: An observational study

BACKGROUND

Rotator cuff related shoulder pain is the most common cause of shoulder pain. Whilst guidelines recommend conservative management prior to imaging, injection or surgical management, recent findings suggest that patients experience management contrary to guideline recommendations.

OBJECTIVES

The aim of this study was to investigate self-reported management among people with rotator cuff related shoulder pain (RCRSP) and their beliefs towards management.

MATERIALS AND METHODS

Cross-sectional survey of people with RCRSP recruited when referred for imaging (n = 120). Electronic survey about demographic factors, management people had had (including imaging, injections, surgery, exercise, adjuncts), and beliefs about treatments. The frequency of various treatments was reported (separately for each cohort and traumatic onset) as well as the timing of interventions related to first-line care.

RESULTS

Most people had tried exercise (99/120, 82.5%) but only one in five people reported exercise was helpful, and one in six reported it was unhelpful or made their symptoms worse. Approximately a third of the cohort reported not receiving activity modification advice (34.2%, 41/120), those that did received inconsistent information. People with both traumatic (imaging 31/43, 72.1%; injections 13/24, 54.2%, surgery 8/21, 38.1%) and atraumatic onset pain (imaging 43/77, 55.8%; injections 31/51, 60.8%, surgery 4/19, 21.1%) had similarly high rates of intervention prior to trialling conservative management. Patient beliefs in regards to management showed trends towards interventionalist care.

CONCLUSION

Patient reported management of RCRSP is often inconsistent with guideline recommended management.

Physiotherapists deliver management broadly consistent with recommended practice in rotator cuff tendinopathy: An observational study

BACKGROUND

Rotator cuff tendinopathy is a common and disabling cause of shoulder pain. While conservative treatment is recommended as initial management, recent findings suggest that general practitioners and rheumatologists do not consistently align with recommended care. This study aimed to survey Australian physiotherapists to explore the extent to which recommended management is being applied.

METHODS

A cross-sectional online survey.

RESULTS

Five hundred and two Australian physiotherapists completed the survey. Results demonstrated the majority of physiotherapists provide conservative management consistent with guideline recommendations, through delivery of exercise and education, comparable to management by physiotherapists in the United Kingdom, Belgium and the Netherlands. Parameters and construction of exercise treatment programs were highly variable within the cohort, qualitative analysis highlighting varied reasoning underpinning these management decisions.

CONCLUSIONS

Australian physiotherapists are broadly consistent with providing recommended management, however heterogeneity exists in the methods and parameters of treatment delivery.

A Quasi-Nonlinear Analysis of the Anisotropic Behaviour of Human Gallbladder Wall

Estimation of biomechanical parameters of soft tissues from noninvasive measurements has clinical significance in patient-specific modeling and disease diagnosis. In this work, we present a quasi-nonlinear method that is used to estimate the elastic moduli of the human gallbladder wall. A forward approach based on a transversely isotropic membrane material model is used, and an inverse iteration is carried out to determine the elastic moduli in the circumferential and longitudinal directions between two successive ultrasound images of gallbladder. The results demonstrate that the human gallbladder behaves in an anisotropic manner, and constitutive models need to incorporate this. The estimated moduli are also nonlinear and patient dependent. Importantly, the peak stress predicted here differs from the earlier estimate from linear membrane theory. As the peak stress inside the gallbladder wall has been found to strongly correlate with acalculous gallbladder pain, reliable mechanical modeling for gallbladder tissue is crucial if this information is to be used in clinical diagnosis.

The effect of argon plasma coagulation ablation on esophageal motility and chemoreceptor sensitivity in Barrett's esophagus patients

Patients with Barrett's esophagus usually demonstrate impaired esophageal motility, which affects acid clearance, together with reduced chemo-receptor sensitivity and symptom severity. Ablative endoscopic techniques are now used to eliminate Barrett's cells. The hypothesis for this study was that ablation with argon plasma coagulation (APC) may affect esophageal sensitivity and motility in patients with Barrett's esophagus, and the aim of this study was to assess differences in these parameters before and after APC treatment. Twenty patients with Barrett's esophagus were investigated before and after APC therapy. After standard pull through manometry, water bolus aliquots were given to assess primary peristalsis and rapid water and air bolus injections to assess secondary peristalsis. Sensitivity studies were carried out using weak solutions of either hydrochloric acid or sodium hydroxide, together with saline washouts. Onset time for typical symptoms (t), sensory intensity rating (I), and a sensory score (SS) = (t) x (I)/100 was observed. There were no significant differences in the lower esophageal sphincter pressures (13.6 mm Hg versus 12.6 mm Hg, P= 0.8) and successful test swallows (3 mm Hg versus 5 mm Hg, P= 0.5) before and after treatment, but there was a trend for secondary peristalsis to improve (air bolus 0 versus 2, P= 0.05, water bolus 0 versus 1, P= 0.07). Sensitivity studies showed a smaller sensitivity intensity rating to both acid (61 versus 31, P= 0.02) and alkaline (91 versus 64, P= 0.03) after treatment. In conclusion, we have shown no substantive changes in esophageal motility after ablation of Barrett's esophagus cells, but have demonstrated reduced sensitivity to reflux type solutions.

Correlation of Mechanical Factors and Gallbladder Pain

Acalculous biliary pain occurs in patients with no gallstones, but is similar to that experienced by patients with gallstones. Surgical removal of the gallbladder (GB) in these patients is only successful in providing relief of symptoms to about half of those operated on, so a reliable pain-prediction model is needed. In this paper, a mechanical model is developed for the human biliary system during the emptying phase, based on a clinical test in which GB volume changes are measured in response to a standard stimulus and a recorded pain profile. The model can describe the bile emptying behaviour, the flow resistance in the biliary ducts, the peak total stress, including the passive and active stresses experienced by the GB during emptying. This model is used to explore the potential link between GB pain and mechanical factors. It is found that the peak total normal stress may be used as an effective pain indicator for GB pain. When this model is applied to clinical data of volume changes due to Cholecystokinin stimulation and pain from 37 patients, it shows a promising success rate of 88.2% in positive pain prediction.

The effect of photodynamic therapy (PDT) on oesophageal motility and acid clearance in patients with Barrett’s oesophagus

BACKGROUND

Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. It is proposed that long-term re-epithelialisation, which has been achieved following ablation using 5-aminolaevulinic acid (5-ALA) photodynamic therapy (PDT) may reduce the risk of malignant change. However, it is not known whether PDT modifies oesophageal motility.

AIM

To assess oesophageal pH and motility before and after PDT ablation in treated and untreated areas of the oesophagus.

METHODS

Twelve patients (10 male) with Barrett's oesophagus, median segment length 4 cm, were treated with PDT ablation. Twenty-four hours pH assessment and oesophageal manometry were performed before and 4-6 weeks after ablation. PDT was carried out using 635 nm red light, 4-6h after administration of 30 mg/kg 5-ALA. Proximal (untreated) and distal (treated) oesophageal resting pressure, wave amplitude, percentage peristalsis and percentage study time oesophageal pH<4, were assessed. Proton pump inhibitors (PPI) were administered throughout the study.

RESULTS

There were no significant differences in oesophageal motility in treated or untreated areas of the oesophagus after PDT compared to pre-treatment values. Patients who continued to experience oesophageal acid exposure required more treatments to achieve complete Barrett's ablation.

CONCLUSIONS

Oesophageal motility following ALA-PDT suggests a trend toward enhanced wave propagation however continued oesophageal acid exposure may affect PDT efficacy.

Bethanechol provocation testing does not predict symptom relief after cholecystectomy for acalculous biliary pain

BACKGROUND

The currently accepted hypothesis to explain acalculous gallbladder pain is the lack of contractile co-ordination between the body and neck. We have previously shown that bethanechol, a muscarinic stimulant causes differential stimulation of these two regions.

AIM

To evaluate the reliability of bethanechol-induced gallbladder contraction in predicting symptom relief after cholecystectomy in patients with acalculous gallbladder disease.

METHODS

Fifty-one patients underwent a bethanechol provocation test together with serial ultrasound to determine gallbladder emptying. McGill pain questionnaires were completed, and patients positive for pain (bethanechol provocation test +ve) were offered cholecystectomy, and patients negative for pain (bethanechol provocation test -ve) were reassessed at 6 months and offered cholecystectomy if symptoms persisted. All patients answered pain questionnaires either 6 months after surgery or as follow-up.

RESULTS

There was no difference in the percentage of gallbladder emptying between the bethanechol provocation test +ve and bethanechol provocation test -ve groups. Fifty-three percent of bethanechol provocation test +ve patients and 54% of bethanechol provocation test -ve patients still remained symptomatic 6 months after surgery. Conclusion. Gallbladder pain provoked by bethanechol does not predict symptom relief after cholecystectomy.

A requiem for the cholecystokinin provocation test?

BACKGROUND

The cholecystokinin provocation test (CCKPT) has been claimed to predict a better symptomatic result after cholecystectomy in patients with acalculous biliary pain.

AIMS

To examine the predictive value of the CCKPT for symptom relief after cholecystectomy in both CCKPT positive and negative patients.

PATIENTS AND METHODS

Fifty eight patients with acalculous biliary pain underwent CCKPT with serial ultrasound gall bladder volumetry. CCKPT positive patients were offered cholecystectomy; negative patients were reassessed and were offered a cholecystectomy if symptoms persisted. Six months after cholecystectomy, the CCKPT was repeated.

RESULTS

Of 32 CCKPT positive patients, 27 underwent cholecystectomy and of these, 18 (67%) became symptom-free. Postoperatively, 20 of 25 patients converted to CCKPT negative but five remained CCKPT positive and were symptomatic. Of the 26 CCKPT negative patients, nine became symptom-free without cholecystectomy; six of 14 (42.8%) patients undergoing cholecystectomy became asymptomatic and remained CCKPT negative. Cholecystectomy seemed to reduce symptoms in both groups, but there was no significant difference in the symptomatic outcome between preoperative CCKPT positive and negative patients.

CONCLUSIONS

In this study, cholecystokinin provocation testing did not predict symptomatic benefit from cholecystectomy and we suggest it should no longer be used in the evaluation of patients with acalculous biliary pain.

Effect of cisapride on oesophageal motility and duodenogastro-oesophageal reflux in patients with Barrett's oesophagus

OBJECTIVE

Both gastric acid and duodenal juice have been implicated in Barrett's oesophagus. The aim of this study was to look at duodenal reflux in the oesophagus together with motility characteristics in a group of patients with Barrett's oesophagus and compare them with a mild oesophagitis group and to assess the effect of cisapride on any abnormalities.

DESIGN

A prospective study comparing the two groups of patients was carried out.

METHODS

Twenty patients with histologically proven Barrett's oesophagus and 20 patients with Savary-Miller grade 2 oesophagitis were studied. Standard oesophageal manometric measurements were carried out and on a separate occasion duodenogastro-oesophageal reflux (DGOR) was measured over a 4-h period using a sodium ion selective electrode. Patients with more than 5% DGOR were given cisapride (10 mg four times daily) and the studies repeated after 7 days of treatment.

RESULTS

Barrett's patients showed more DGOR, 12.2% of the study time compared to 5.1% in the mild oesophagitis group, P = 0.012, but manometric findings were not significantly different. Sixteen patients were treated with cisapride. DGOR was reduced in 8 out of 12 Barrett's patients and 2 out of 4 oesophagitis patients, and proximal amplitude and distal oesophageal pressures were significantly elevated (P = 0.05 and P = 0.03, respectively).

CONCLUSION

Monitoring of sodium ions in the oesophagus shows that patients with Barrett's oesophagus have significantly more DGOR than patients with uncomplicated oesophagitis and cisapride may be effective in removal of this reflux.

A recombinant GM-CSF-PE40 ligand toxin is functionally active but not cytotoxic to cells

A granulocyte/macrophage colony-stimulating factor (GM-CSF)-Pseudomonas exotoxin (PE) 40 fusion protein was constructed for potential use in the treatment of myeloid leukaemias, as a conditioning agent prior to allogeneic bone marrow transplantation or for ex vivo purging of malignant cells prior to autologous bone marrow transplantation. The GM-CSF-PE40 fusion protein successfully binds to the GM-CSF receptor and is capable of initiating a mitogenic signal similar to native GM-CSF in the GM-CSF-dependent TF1 cell line. The toxin component also appears to be fully functional as determined by an in vitro adenosine diphosphate-ribosylation assay. The GM-CSF-PE40 fusion protein, however, was not cytotoxic to a number of myeloid leukaemia cell lines. It is suggested that the mechanism of internalization of the GM-CSF receptor is not appropriate for the translocation of PE to the cytosol where it can fulfil its cytotoxic potential.

Evidence that adenosine triphosphate or a related nucleotide is the transmitter substance released by non-adrenergic inhibitory nerves in the gut. 1970

Stimulation of the vagal non-adrenergic inhibitory innervation caused the release of adenosine and inosine into vascular perfusates from the stomachs of guinea-pigs and toads. Stimulation of portions of Auerbach's plexus isolated from turkey gizzard caused the release of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP). ATP, added to solutions perfused through the toad stomach vasculature, was broken down to adenosine, inosine and adenine. Of a series of purine and pyrimidine derivatives tested for inhibitory activity on the guinea-pig isolated taenia coli, ATP and ADP were the most potent. ATP caused inhibition of twelve other gut preparations previously shown to contain non-adrenergic inhibitory nerves. The inhibitory action of ATP was not prevented by tetrodotoxin. Quinidine antagonized relaxations of the guinea-pig taenia coli caused by catecholamines or adrenergic nerve stimulation. Higher concentrations of quinidine antagonized relaxations caused by ATP or non-adrenergic inhibitory nerve stimulation. When tachyphylaxis to ATP had been produced in the rabbit ileum, there was a consistent depression of the responses to non-adrenergic inhibitory nerve stimulation but not of responses to adrenergic nerve stimulation. It is suggested that ATP or a related nucleotide is the transmitter substance released by the non-adrenergic inhibitory innervation of the gut.

Detection of duodenal fluid in the oesophagus with a sodium ion selective electrode

The assessment of duodeno-oesophageal reflux is difficult as, until recently, no technique has been readily available for continuous ambulatory monitoring. A sodium ion selective electrode placed in the stomach has been previously shown to detect duodenogastric reflux by using sodium as a marker. This relies on the difference in sodium concentration between gastric (5-60 mmol/L) and duodenal, biliary and pancreatic (150 mmol/L) fluids. In this pilot study to assess the efficacy of the electrode in the distal oesophagus, eight subjects without symptomatic gastro-oesophageal reflux and eight subjects with known duodenogastric reflux were studied. Thirty millilitre volumes of varying sodium solutions (40, 80, 100 and 140 mmol/L) were swallowed to assess the response of the electrode to sodium ions. In both groups, this revealed a constant and reproducible rise in response with increasing concentration (P < 0.0001). The stomachs of subjects with duodenogastric reflux were aspirated via a nasogastric tube to obtain 12 different samples of gastric fluid. This was assayed for sodium and bile acid concentration. The fluid was then reinfused as a 30 mL bolus into the oesophagus through a tube to simulate oesophageal reflux. A rise equivalent to 40-72 mmol/L Na+ was recorded by the electrode in response to samples that contained 58-81 mmol/L Na+ and 0.4-16 mmol/L bile acids, recorded by quantitative analysis, and a response of up to 20 mmol/L Na+ was recorded by the electrode to sodium concentrations < 49 mmol/L and bile acid concentrations of 0.005-0.6 mmol/L. The response was appropriate to the assayed bile acid concentration in all but one sample. The sodium ion selective electrode responds to bile containing fluids introduced into the oesophagus. Further investigation is warranted to determine its ability to measure duodeno-oesophageal reflux continuously.

Randomised, prospective, single-blind comparison of laparoscopic versus small-incision cholecystectomy

BACKGROUND

We report a prospective randomised comparison between laparoscopic and small-incision cholecystectomy in 200 patients which was designed to eliminate bias for or against either technique.

METHODS

Patients were randomised in the operating theatre and anaesthetic technique and pain-control methods were standardised. Four experienced surgeons did both types of procedure. Identical wound dressings were applied in both groups so that carers could be kept blind to the type of operation.

FINDINGS

There was no significant difference between the groups for age, sex, body mass index, and American Society of Anaesthesiologists grade. Laparoscopic cholecystectomy took significantly longer than small-incision cholecystectomy (median 65 [range 27-140] min vs 40 [18-142] min, p<0.001). The operating time included operative cholangiography which was attempted in all patients. We found no significant difference between the groups for hospital stay (postoperative nights in hospital, median 3-0 [1-17] nights for laparoscopic vs 3-0 [1-14] nights for small-incision, p=0.74), time back to work for employed persons (median 5-0 weeks vs 4.0 weeks; p=0.39), and time to full activity (median 3-0 weeks vs 3.0 weeks; p=0.15).

INTERPRETATION

Laparoscopic cholecystectomy takes longer to do than small-incision cholecystectomy and does not have any significant advantages in terms of hospital stay or postoperative recovery.

Levels of messenger-RNA coding for DNA topoisomerase-ii isoforms do not correlate with in-vitro drug-sensitivity

The relationship between cellular levels of mRNA coding for DNA topoisomerase II, both the alpha and beta isoforms, and in vitro sensitivity to anticancer drugs were evaluated. Using a sensitive RNA-polymerase chain reaction technique, the levels of mRNA coding for the alpha and beta isoforms of topoisomerase II were estimated relative to beta-actin mRNA. A relatively narrow range of expression was observed across a broad range of approximately 60 human tumor cell lines representing eight major histological types which have been characterized in detail with respect to their in vitro sensitivity to standard anticancer drugs. No significant correlations were observed between mRNA level and cellular response to drugs thought to inhibit topoisomerase II or any of the other drugs studied. These results suggest that predictive tests for response to topoisomerase II-related drugs can not be based on estimation of levels of mRNA.

Duodenogastric reflux after gastric surgery and in gastric ulcer disease: continuous measurement with a sodium ion selective electrode

Duodenogastric reflux (DGR) was investigated with a sodium ion selective electrode in 10 normal controls, 10 patients with persistent pain after gastric surgery, and five patients with gastric ulcer. During an average study time of two and a half hours, normal controls had reflux for 12% of the study, whereas patients after gastric surgery had reflux for 91% of the study time (p < 0.0002). Patients with a gastric ulcer had reflux on average for 67% of the study (p < 0.001). The patients who had had gastric surgery had several symptoms, but there was no association between the number or nature of symptoms and the severity of DGR as determined by the sodium electrode. Patients with positive bile provocation tests did not show any significant difference in the duration of reflux compared with those with a negative provocation test (79% and 87%). There was also no relation between the results of the provocation test and the number and nature of symptoms. Continuous monitoring of intragastric sodium ions with a selective electrode is a practical means of assessing DGR. Results suggest that symptoms due to DGR may be related to the sensitivity of the gastric lining as well as the amounts of duodenal contents flowing back into the stomach.

Continuous monitoring of sodium ion concentration in the human stomach--a new technique for the detection of duodenogastric reflux

Measurement of sodium ion concentration in gastric juice offers a simple means of detecting duodenogastric reflux (DGR). Using aspirated gastric juice, we measured sodium ion concentration, bile acid levels and phospholipase A2 activity and found that sodium ion levels increase along with these other standard markers during DGR. Following this, using a sodium ion selective electrode and a portable data logger, continuous recordings of sodium ion concentration were made in the human stomach. These studies demonstrated the ability of sodium ion monitoring to detect major DGR episodes in the body of the stomach.

Relative contribution of bile and pancreatic juice duodenogastric reflux in gastric ulcer disease and cholelithiasis

Bile acid concentrations, phospholipase A2 activity and pH in the stomach were measured in the fasting state and for 2 h after a fat-containing test meal in patients with an active gastric ulcer (GU), in patients with gallstones before and after cholecystectomy and in normal subjects. Fasting and peak postprandial bile acid concentrations in the stomach were low in all normal controls. Although high concentrations were found in many patients with GU (P less than 0.01), similar concentrations were found in many patients with radiologically non-functioning gallbladders containing gallstones (NFG) (P less than 0.01) and also after cholecystectomy (AC) (P less than 0.01). Fasting intragastric phospholipase A2 activities were similar, and very high in GU and NFG patients compared with control subjects (P less than 0.01). High values were not found after cholecystectomy. There was no difference in pH profile or in postprandial phospholipase A2 between patient groups. Since patients with cholelithiasis or after cholecystectomy are not known to have an increased incidence of gastric ulceration, the significance of duodenogastric reflux in the aetiology of gastric ulcers must be questioned. If reflux does produce ulcers in GU patients then factors in addition to bile acid are probably involved. However, neither patterns of phospholipase A2 reflux nor pH profiles can explain the absence of gastric ulceration in those patients with gallstones who reflux large quantities of bile acid.

The ability of antacids and cholestyramine to bind bile acids: effect of pH

Reflux of bile into the stomach may be injurious to the gastric mucosa. The ability of antacids and cholestyramine to bind bile acids is therefore potentially valuable in the treatment of reflux gastritis. The ability of antacids and cholestyramine to remove bile acids from gastric juice, hepatic bile, and solutions of commercially available bile acids was investigated in vitro over a pH range likely to occur in the stomach. The percentage of bile acids removed by antacids decreased with decreasing initial bile acid concentration and usually decreased as the incubation pH was increased from 3.6 to 7.0. Glycine-conjugated bile acids were bound to a greater extent than taurine-conjugated bile acids and dihydroxy to a greater extent than trihydroxy bile acids. Cholestyramine bound 97-100% of all bile acids in solution at pH 3.6 and pH 7.0. The effect of pH on adsorption should therefore be considered when antacids are used to treat gastritis.

An experimental study of the healing of secondary abdominal incisions

An experimental study of the healing of separate secondary abdominal incisions in rats has been performed. After an initial right subcostal incision, a vertical left-sided abdominal wound was made 1 or 2 weeks later. Wound healing was assessed by measurement of changes in mechanical strength and collagen deposition. The results indicate that an increase in mechanical strength was not effected by initial wounding despite alterations in collagen metabolism.

Does obstructive jaundice adversely affect wound healing?

The effect of obstructive jaundice on wound healing has been investigated in an experimental study of abdominal wounds in rats following ligation and division of the common bile duct. Animals were jaundiced for 2 weeks before a second operation at which the abdominal wounds were made. The wounds in jaundiced and control animals showed no significant differences in mechanical strength during a 21-day period of study but there was a significant delay in the accumulation of collagen in the wounds of jaundiced animals. The findings suggest that the biochemical changes in the wounds of jaundiced animals did not interfere with wound repair and cast doubt on the thesis that jaundice has an adverse effect on wound healing.

Ascorbic acid requirements in postoperative patients

The postoperative ascorbic acid requirements of 63 surgical patients were assessed by measurements of buffy layer leukocyte ascorbic acid and the ascorbic acid content of leukocytes. There was a significant reduction in ascorbic acid levels following operation. The postoperative changes were unrelated to the extent of surgical trauma or the volume of blood transfused during operation, but there was a significant correlation between postoperative ascorbic acid measurements and white blood counts. It appears that postoperative leukocytosis and release by the bone marrow of leukocytes with a low ascorbic acid content may partly account for the postoperative changes in buffy layer and leukocyte ascorbic acid measurements. However, surgical operations were followed by an authentic increase in ascorbic acid requirements, and there was a 42 per cent reduction in circulating leukocyte ascorbic acid levels on the third postoperative day. The findings of this study create an argument for the use of ascorbic acid supplements in surgical patients, although it is unlikely that postoperative changes in leukocyte ascorbic acid have pathologic significance in wound repair.

Neonatal islet cell transplantation in the diabetic rat: effect on the renal complications

PVG/C rats were made diabetic with streptozotocin and after 1 mth received a single intraperitoneal transplant of isogeneic collagenase digested pancreatic tissue. Renal changes have been studied in transplanted and control diabetic rats using light and electron microscopy and immunological techniques. Following transplantation, renal lesions did not increase in severity and progressive basement membrane thickening was prevented. Ultrastructurally many glomeruli showed a significant reduction in the mesangial matrix and the tubular and mesangial cell changes reverted to normal. Immunofluorescent studies demonstrated a similar reduction in the glomerular deposits of IgG. Possibilities for the treatment of diabetes mellitus in human patients are discussed.

Neonatal islet cell transplantation in the diabetic rat: effect on hepatic enzyme activity and glucose homeostasis

Intraperitoneal transplantation of collagenase-digested, isogeneic, neonatal rat pancreatic tissue successfully reversed streptozotocin-induced diabetes in 77% of recipients. The low serum immunoreactive insulin, hyperglycaemia, glycosuria and weight loss, characteristic of the diabetic animal, were corrected and the reduced activities of hepatic glucokinase and pyruvate kinase, and the low glycogen concentration of the liver of diabetic rats were restored to normal. Forty-three per cent of the successfully transplanted rats became normoglycaemic within 1 month of transplantation whereas 57% took from 1 to 6 months to achieve normoglycaemia and displayed a mild glucose intolerance when subjected to a glucose load. The rats which had not become normoglycaemic 6 months after transplantation showed some amelioration of the diabetic state, as shown by increased serum immunoreactive insulin and hepatic glycogen concentration and a slow weight gain compared with diabetic controls.

Pancreatic ischaemia; sensitivity and reversibility of the changes

In the rat, pancreatic clamping producing warm ischaemic times ranging from 5 to 90 min gives rise to changes similar to those of an haemorrhagic pancreatitis. The severity of the changes is proportional to the time of ischaemia. After 1 to 1 1/2 h clamping 95 per cent of the glandular changes are reversible, and at 2 months the pancreas appears normal apart from localized areas of fibrosis. The islets of Langerhans remain morphologically normal even after 90 min ischaemia. The implications for islet cell transplantation are discussed.

The influence of exogenous PMS and HCG on the arachidonic acid content of the immature rat ovary

The influence of exogenous PMS and/or HCG, on the arachidonic acid (C 20:4omega6) content of the immature rat ovary was examined. Changes in ovarian arachidonate content associated with hormone administration were assessed in total lipid extracts, and in several neutral and phospholipid fractions. Both relative percentage and absolute amounts of arachidonic acid in several lipids were measured as well as uptake of radioactivity into total lipid resulting from the administration of 3H-labeled arachidonic acid in vivo. On the basis of these studies, we conclude (1) PMS, with or without HCG promotes increased uptake of exogenous arachidonic acid into ovarian total lipids; (2) Arachidonic acid is a mojor fatty acid constituent from noncholine containing phosphatides at the onset of normal estrous (ca. 38 days) even in the animals which received no PMS or HCG; (3) Changes in ovarian arachidonic acid levels following gonadotropin administration are more striking in the two phospholipid fractions than in the two neutral lips examined; (4) PMS is associated with a rapid outpouring of ovarian lipid, accompanied by a high turnover of arachidonic acid which is enhanced or modified temporally by added HCG in vivo. These results provide the first quantitative evidence that gonadotropins may regulate prostaglandin biosynthesis in the ovary by their effects on the uptake, storage, or release of arachidonic acid, a major PG precursor, from specific ovarian lipids. While the data strongly suggest that the regulation of one or more ovarian esterases (cholesterol esterase, lipase, phospholipase) is the mechanism by which gonadotropins regulate PG biosynthesis, a direct action on PG synthetase is not ruled out.

A comparison of the excitatory and inhibitory effects of non-adrenergic, non-cholinergic nerve stimulation and exogenously applied ATP on a variety of smooth muscle preparations from different vertebrate species

1. The responses to non-adrenergic, non-cholinergic nerve stimulation have been compared with those to exogenously applied ATP on seventeen different tissues from a number of vertebrate classes.2. Stimulation of all the mammalian gut preparations studied (with the exception of the guinea-pig ileum) after blockade of the effects of adrenergic and cholinergic nerve stimulation by guanethidine (3.5 muM) and hyoscine (1.3 muM) caused inhibition; exogenously applied ATP mimicked this inhibitory response.3. Stimulation of the guinea-pig ileum in the presence of hyoscine and guanethidine, usually caused a diphasic response, relaxation followed by contraction; exogenously applied ATP mimicked this response, in contrast to acetylcholine and noradrenaline which caused excitation and relaxation respectively.4. Stimulation of preparations of lower vertebrate gut and guinea-pig bladder in the presence of hyoscine and guanethidine caused contraction; exogenously applied ATP mimicked this contractile response.5. In each preparation the time course of the response to ATP was similar or identical to the response to non-adrenergic, non-cholinergic nerve stimulation.6. The results are consistent with the hypothesis that a purine nucleotide may be the transmitter substance released from non-adrenergic, non-cholinergic nerves supplying smooth muscle preparations from a number of vertebrate classes.

Atropine resistant excitation of the urinary bladder: the possibility of transmission via nerves releasing a purine nucleotide

1. The possibility that a purine nucleotide is involved in excitatory transmission to the urinary bladder has been tested. All the purine compounds tested which contained a pyrophosphate bond produced contraction, adenosine triphosphate (ATP) being the most potent. Adenosine and adenosine monophosphate caused relaxation.2. The response to ATP closely mimicked the nerve-mediated contraction, both being characterized by a rapid contraction which was not maintained. A lack of sensitivity to ATP was noted in some preparations of the rat urinary bladder.3. Both nerve-mediated contractions and contractions caused by ATP were blocked by quinidine, while the response to acetylcholine persisted.4. Nerve-mediated responses were depressed during tachyphylaxis produced by high concentrations of ATP. Tachyphylaxis did not occur when low concentrations were used. Possible explanations for these results are discussed.5. The results are consistent with the hypothesis that non-cholinergic excitatory nerves to the guinea-pig bladder release a purine nucleotide, but do not provide critical evidence for it.

Evidence that adenosine triphosphate or a related nucleotide is the transmitter substance released by non-adrenergic inhibitory nerves in the gut

1. Stimulation of the vagal non-adrenergic inhibitory innervation caused the release of adenosine and inosine into vascular perfusates from the stomachs of guinea-pigs and toads.2. Stimulation of portions of Auerbach's plexus isolated from turkey gizzard caused the release of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP).3. ATP, added to solutions perfused through the toad stomach vasculature, was broken down to adenosine, inosine and adenine.4. Of a series of purine and pyrimidine derivatives tested for inhibitory activity on the guinea-pig isolated taenia coli, ATP and ADP were the most potent.5. ATP caused inhibition of twelve other gut preparations previously shown to contain non-adrenergic inhibitory nerves. The inhibitory action of ATP was not prevented by tetrodotoxin.6. Quinidine antagonized relaxations of the guinea-pig taenia coli caused by catecholamines or adrenergic nerve stimulation. Higher concentrations of quinidine antagonized relaxations caused by ATP or non-adrenergic inhibitory nerve stimulation.7. When tachyphylaxis to ATP had been produced in the rabbit ileum, there was a consistent depression of the responses to non-adrenergic inhibitory nerve stimulation but not of responses to adrenergic nerve stimulation.8. It is suggested that ATP or a related nucleotide is the transmitter substance released by the non-adrenergic inhibitory innervation of the gut.