Association of Genetic Variants in NUDT15 With Thiopurine-Induced Myelosuppression in Patients With Inflammatory Bowel Disease

IMPORTANCE

Use of thiopurines may be limited by myelosuppression. TPMT pharmacogenetic testing identifies only 25% of at-risk patients of European ancestry. Among patients of East Asian ancestry, NUDT15 variants are associated with thiopurine-induced myelosuppression (TIM).

OBJECTIVE

To identify genetic variants associated with TIM among patients of European ancestry with inflammatory bowel disease (IBD).

DESIGN, SETTING, AND PARTICIPANTS

Case-control study of 491 patients affected by TIM and 679 thiopurine-tolerant unaffected patients who were recruited from 89 international sites between March 2012 and November 2015. Genome-wide association studies (GWAS) and exome-wide association studies (EWAS) were conducted in patients of European ancestry. The replication cohort comprised 73 patients affected by TIM and 840 thiopurine-tolerant unaffected patients.

EXPOSURES

Genetic variants associated with TIM.

MAIN OUTCOMES AND MEASURES

Thiopurine-induced myelosuppression, defined as a decline in absolute white blood cell count to 2.5 × 109/L or less or a decline in absolute neutrophil cell count to 1.0 × 109/L or less leading to a dose reduction or drug withdrawal.

RESULTS

Among 1077 patients (398 affected and 679 unaffected; median age at IBD diagnosis, 31.0 years [interquartile range, 21.2 to 44.1 years]; 540 [50%] women; 602 [56%] diagnosed as having Crohn disease), 919 (311 affected and 608 unaffected) were included in the GWAS analysis and 961 (328 affected and 633 unaffected) in the EWAS analysis. The GWAS analysis confirmed association of TPMT (chromosome 6, rs11969064) with TIM (30.5% [95/311] affected vs 16.4% [100/608] unaffected patients; odds ratio [OR], 2.3 [95% CI, 1.7 to 3.1], P = 5.2 × 10-9). The EWAS analysis demonstrated an association with an in-frame deletion in NUDT15 (chromosome 13, rs746071566) and TIM (5.8% [19/328] affected vs 0.2% [1/633] unaffected patients; OR, 38.2 [95% CI, 5.1 to 286.1], P = 1.3 × 10-8), which was replicated in a different cohort (2.7% [2/73] affected vs 0.2% [2/840] unaffected patients; OR, 11.8 [95% CI, 1.6 to 85.0], P = .03). Carriage of any of 3 coding NUDT15 variants was associated with an increased risk (OR, 27.3 [95% CI, 9.3 to 116.7], P = 1.1 × 10-7) of TIM, independent of TPMT genotype and thiopurine dose.

CONCLUSIONS AND RELEVANCE

Among patients of European ancestry with IBD, variants in NUDT15 were associated with increased risk of TIM. These findings suggest that NUDT15 genotyping may be considered prior to initiation of thiopurine therapy; however, further study including additional validation in independent cohorts is required.

Poor tolerability of thalidomide in end-stage oesophageal cancer

Oesophageal cancer cachexia is a significant clinical problem, resulting in excessive morbidity and mortality. In a pilot study, 10 patients with cachexia due to advanced cancer of the oesophagus gained weight, including lean tissue, after 14-day treatment with thalidomide. Here, we present randomised placebo controlled trial data over a 6-week period to test the hypothesis that thalidomide is superior to placebo in terms of weight gain in patients with cachexia caused by oesophageal cancer. Thalidomide, 200 mg daily, or an identical placebo was given to patients with advanced oesophageal cancer. Total body weight and lean body mass were assessed in addition to drug tolerability and performance indices. Thirty-four patients were recruited. Of these, six given thalidomide and 16 given placebo completed the protocol; all withdrawals were due to adverse drug reactions or complications of disease. Thalidomide showed no benefit over placebo in participants who completed the protocol. These data suggest that thalidomide is poorly tolerated in patients with advanced cancer of the oesophagus and may not ameliorate the progression of cachexia. In the absence of hard supportive evidence, off-licence treatment with thalidomide should be used with great caution as an adjunct to nutritional support in patients with advanced cancer.

Oesophageal cancer and cachexia: the effect of short-term treatment with thalidomide on weight loss and lean body mass

BACKGROUND

Cachexia is common in patients with advanced cancer and has a direct impact on well-being and mortality.

AIM

To test the hypothesis that thalidomide can promote weight gain and lean body mass in patients with advanced oesophageal cancer.

METHODS

In an open-label study, 11 patients with non-obstructing and inoperable oesophageal cancer were established on an isocaloric diet for 2 weeks, followed by 2 weeks on thalidomide, 200 mg daily. The primary end-points were weight change and lean body mass. Secondary end-points were quality of life and changes in resting energy expenditure.

RESULTS

Ten patients completed the study protocol. The average caloric intake remained the same throughout the study period in all patients. Nine of 10 patients (95% confidence interval, 0.60, 0.98) lost weight on diet alone. The mean weight gain on thalidomide in the following 2 weeks was 1.29 kg (median, 1.25 kg). A similar trend was shown in the lean body mass. Eight of nine patients (95% confidence interval, 0.57, 0.98) initially lost lean body mass on diet alone (missing data in one patient). The mean gain in lean body mass on thalidomide in the following 2 weeks was 1.75 kg (median, 1.33 kg).

CONCLUSIONS

Thalidomide treatment appeared to reverse the loss of weight and lean body mass over the 2-week trial period.

Placement of esophageal self-expanding metallic stents without fluoroscopy

BACKGROUND

Fluoroscopy is routinely used to guide the placement of self-expanding metallic stents for the palliative treatment of patients with esophageal malignancy. This is a description of a novel method of stent placement without fluoroscopy.

METHODS

This technique relies on a clear endoscopic view of the proximal radiopaque marker on the stent. This was achieved by the application of an external white marker at this level. A gastroscope was passed, allowing guidewire deployment and measurement of stricture length. The endoscope was reinserted and placed alongside the guidewire giving direct visualization of the proximal margin of the stricture. The stent delivery device was positioned, keeping the white mark visible proximal to the stricture, and the stent was deployed.

RESULTS

Thirty consecutive patients with inoperable esophageal malignancy underwent endoscopic placement of self-expanding metal stents. Deployment in satisfactory position without fluoroscopy was successful in 23 of 30 (77%); there were no complications.

CONCLUSIONS

The majority of esophageal stents can be accurately positioned without fluoroscopy.

Drug treatments in upper gastrointestinal bleeding: value of endoscopic findings as surrogate end points

INTRODUCTION

Pharmacotherapy for upper gastrointestinal bleeding has been difficult to evaluate because clinical end points are infrequent and affected by other factors.

AIMS

To evaluate whether blood in the stomach at endoscopy reflected severity of bleeding, predicted clinical outcomes, and could be altered by therapeutic agents.

METHODS

We studied 414 consecutive admissions with suspected upper gastrointestinal bleeding. Patients were randomised to receive lansoprazole 60 mg followed by 30 mg four times daily, tranexamic acid 2 g followed by 1 g four times daily, both drugs, or placebo for four days, until discharge or a clinical end point occurred. Logistic regression analysis was used to determine predictors of endoscopic changes and clinical outcomes, and to investigate the effects of drug treatments on blood in the stomach.

RESULTS

Of 414 patients with suspected upper gastrointestinal bleeding, 379 were endoscoped. Upper gastrointestinal bleeding was confirmed in 316. Sixteen required surgery within 30 days and 16 died on the index admission. Trial treatments were evaluable on a per protocol basis in 228 patients. The amount of blood in the stomach was found to reflect initial risk, with significant associations with high risk categorisation (odds ratio 3.7 (95% confidence interval 1.5-9.4) for more than a trace v none/trace), age (1.5 (1.1-1.9) per decade), and initial pulse (1.02 (1.00-1.04) per beat), and to predict rebleeding (9.2 (4.6-18.7)) and surgery (8.2 (2.9-22.9)). Other stigmata were less significant in these respects. The amount of blood in the stomach at endoscopy was reduced significantly by both lansoprazole (0.22 (0.07-0.63)) and tranexamic acid (0.27 (0.09-0.81)), although there was no evidence of synergy.

CONCLUSIONS

Blood in the stomach reflects clinical features in patients with acute upper gastrointestinal bleeding and is reduced by treatment with lansoprazole and tranexamic acid.

Protection of human gastric mucosa against aspirin-enteric coating or dose reduction?

BACKGROUND

Aspirin is widely used for cardiovascular prophylaxis.

AIM

To compare the effectiveness of two widely-used strategies-dose reduction and enteric coating-for the minimization of gastric mucosal injury or toxicity.

METHODS

Twelve healthy volunteers were studied. On four separate occasions each received, under blinded conditions, five daily doses of plain aspirin 300 mg, plain aspirin 75 mg, enteric-coated aspirin 300 mg or placebo. Ex vivo prostaglandin E2 synthesis was stimulated by the vortex mixing of gastric mucosal biopsies in Tris saline and measured by radioimmunoassay. Mucosal injury was quantified both by counting erosions and with a visual analogue scale.

RESULTS

All three preparations reduced prostaglandin E2 synthesis by day five, by (median) 84% for plain aspirin 300 mg, by 80% for enteric coated aspirin 300 mg and by 63% for plain aspirin 75 mg. There was little mucosal injury prior to the start of each dose and period and no significant change with placebo. Plain aspirin caused a dose-dependent mucosal injury, with two (median, IQR 0-7) gastric erosions after five days of plain aspirin 75 mg, and 18 (2-26) after five days of plain aspirin 300 mg. With enteric-coated aspirin 300 mg there were 0 (0-1) gastric erosions (P = 0.003 compared to plain aspirin 300 mg P = 0.11, compared to plain aspirin 75 mg).

CONCLUSION

Enteric coated aspirin reduces acute gastric mucosal injury to placebo levels, despite its inhibition of prostaglandin synthesis. Enteric coating is an appropriate strategy for the prevention of gastric mucosal damage induced by low-dose aspirin, which warrants systematic clinical evaluation.

Platelet responses to several agonists and combinations of agonists in whole blood: a placebo controlled comparison of the effects of a once daily dose of plain aspirin 300 mg, plain aspirin 75 mg and enteric coated aspirin 300 mg, in man

Platelet responses to several agonists and combinations of agonists have been measured in whole blood from healthy volunteers. We have determined the effects of once daily treatment for five days with plain aspirin 300 mg, plain aspirin 75 mg, enteric coated aspirin 300 mg or placebo. Measurements were made of platelet aggregation (using a platelet counting technique) and the release reaction (14C-5HT release from pre-labelled platelets). The extents of these responses before aspirin administration depended on the agonist used. ADP, adrenaline and PAF failed to induce any 14C-5HT release in most subjects, but combinations of these agonists acted synergistically to produce extensive 14C-5HT release. All three aspirin preparations reduced the extent of the platelet responses to most agonists: platelet aggregation induced by collagen, ristocetin and arachidonate and 14C-5HT release induced by collagen, streptokinase, and various combinations of ADP, adrenaline and PAF. None of the preparations had any effect on the aggregation that occurred in the absence of an agonist (spontaneous aggregation), but they all reduced streptokinase-induced aggregation to control (spontaneous) levels, and abolished the 14C-5HT release induced by arachidonate and by ristocetin. All three aspirin preparations were equally effective after two daily doses. No further inhibition of platelet responses was obtained after five daily doses. Plain aspirin 300 mg achieved its maximal effect after only a single dose, but enteric coated aspirin 300 mg (and sometimes plain aspirin 75 mg) produced sub-maximal inhibition after only a single dose. Parallel investigations on the effects of these aspirin regimes on gastric mucosal prostaglandin E2 synthesis and gastroduodenal mucosal injury were performed. These results will be reported separately.

Effect of sucralfate on aspirin induced mucosal injury and impaired haemostasis in humans

BACKGROUND

Sucralfate does not have potent anti-ulcerogenic actions in users of non-steroidal anti-inflammatory drugs (NSAIDs). However, sucralfate may influence intragastric haemostasis favourably.

AIM

To investigate separately the effects of sucralfate on acute gastric and duodenal injury and on changes in intragastric bleeding induced by aspirin.

METHOD

On three occasions, 24 healthy volunteers received three days' treatment with aspirin 900 mg twice daily together with placebo, sucralfate 2 g twice daily or sucralfate 1 g four times daily. Injury was assessed endoscopically and bleeding by spontaneous and biopsy induced bleeding intragastric washings. Ex vivo prostaglandin E2 (PGE2) synthesis and serum thromboxane were measured by using radioimmunoassay.

RESULTS

Aspirin significantly inhibited ex vivo gastric mucosal PGE2 synthesis, reduced serum thromboxane, caused gastric erosions, and increased spontaneous and biopsy induced bleeding. Sucralfate had no significant effects on endoscopic injury but sucralfate 1 g four times daily significantly reduced spontaneous and biopsy induced bleeding. Similar trends were seen with sucralfate 2 g twice daily but the results were less consistent.

CONCLUSION

Sucralfate does not affect aspirin induced acute gastric mucosal injury but reduces aspirin associated intragastric bleeding.

Mucosal factors inducing neutrophil movement in ulcerative colitis: the role of interleukin 8 and leukotriene B4

BACKGROUND

The movement of neutrophils into the colonic mucosa in ulcerative colitis is induced by chemokines including interleukin 8 (IL8) and leukotriene B4 (LTB4).

AIMS

To compare the ability of mucosa from ulcerative colitis patients and controls to stimulate neutrophil movement, to define the contribution of LTB4 to this, and to define the relative biological importance of LTB4 and IL8.

PATIENTS

Resected mucosa was obtained from seven control patients and 10 patients with ulcerative colitis.

METHODS

Mucosal homogenate supernatants were used to stimulate isolated neutrophils and the effect assessed by the neutrophil shape change response. Responses were inhibited with either the LTB4 receptor antagonist SC41930- or neutralising anti-IL8 antibody. LTB4 was extracted and assayed by RIA.

RESULTS

Homogenate supernatants from inflamed mucosa were more bioactive (median 1.2 mg/ml-1 induced 50% response) than those from uninflamed mucosa (4.25 mg/ml-1 induced 50% response; difference 2.8 mg/ml-1 (96.5% CI 0.5 to 6.1, p < 0.05). Maximal inhibition by SC41930 of the response was significantly greater in inflamed mucosa (54% median) than in uninflamed mucosa (34%). This inhibition correlated with the level of immunoreactive LTB4 (r = 0.78). Anti-IL8 reduced bioactivity of homogenate supernatants from inflamed mucosa (at 1:10 dilution) by 11.4% (IQR 1.2 to 51.8, p = 0.021) whereas SC41930 reduced it by 54.8% (35.6 to 77.5, p = 0.008).

CONCLUSIONS

Inflamed colonic mucosa releases more neutrophil movement inducing bioactivity than uninflamed mucosa, and has greater LTB4 dependent activity. It yields both IL8 and LTB4 dependent activity but greater LTB4 dependent activity.

Comparison of effects of calcium carbasalate and aspirin on gastroduodenal mucosal damage in human volunteers

Calcium carbasalate is a therapeutically active salicylate which seems to cause less gastroduodenal mucosal damage than aspirin in laboratory animals. This endoscopist-blinded, randomised, cross over trial aimed to compare acute gastric mucosal damage in 20 healthy volunteers treated with acetyl salicylic acid (ASA) (650 mg three times daily) and effervescent calcium carbasalate (ECC) (826.8 mg three times daily) bioequivalent to 650 mg ASA over a five day period. Endoscopy was performed immediately before treatment and on day 5 of each treatment. Serum salicylate, thromboxane B2, and gastric mucosal prostaglandin E2 (PGE2) concentrations were measured after endoscopy. ECC caused fewer gastric mucosal erosions than ASA. The total number of gastric erosions was 23.8 (16.1) in the ASA treated subjects compared with 9.1 (8.7) in ECC treated subjects (p = 0.004). Differences between ASA and ECC were significant for both the gastric antrum and body, and for both haemorrhagic and non-haemorrhagic erosions. The mean gastric body Lanza score for mucosal damage was lower after ECC than ASA (p = 0.003). The visual analogue score for gastric body damage was lower for ECC (16.9 mm (15.9)) than for ASA (32.7 mm (20.8)), p = 0.008. Serum salicylate concentrations were similar after both preparations (ASA: 66 (23) mg/l, versus ECC: 58 (17) mg/l, NS). Serum thromboxane B2 was similarly reduced using both preparations-97.2 (3.5)% inhibition with ASA, 95.2 (5.5)% inhibition with calcium carbasalate (NS). Suppression of gastric mucosal PGE2 synthesis was similar with both preparations (ASA: 83.4 (17.1)%; ECC 84.3 (12.9)%; NS). It is concluded that ECC causes significantly less gastroduodenal mucosal damage than ASA administered at bioequivalent doses as judged by serum salicylate, serum thromboxane, and mucosal PGE2 values. ECC may therefore be a less harmful alternative treatment to plain ASA.

A flow cytometric method to measure shape change of human neutrophils

1. We report a flow cytometric method in which changes in forward angle light scatter are shown to correlate with microscopically evaluated shape change in stimulated human neutrophils. Neutrophil movement and chemotaxis is conventionally measured using Boyden chambers, which is a laborious and exacting technique. Microscopic scoring of neutrophil shape change has been shown to correlate well with Boyden chamber measurements, and although less laborious, still requires manual counting. 2. We now show that measurement of forward angle light scatter in a benchtop flow cytometer correlates closely with microscopic evaluation of neutrophil shape change in dose-response stimulation experiments with leukotriene B4, N-formyl-methionine-leucine-phenylalanine or interleukin-8. The relationship between shape change and increased forward angle light scatter was confirmed using the fluorescence-activated cell sorter to separate partially stimulated neutrophils, followed by reanalysis by flow cytometry and microscopic examination. 3. This flow cytometric method provides a convenient, rapid and objective measure of neutrophil responses to external stimuli.

Low dose aspirin: selective inhibition of rectal dialysis thromboxane B2 in healthy volunteers

AIM

To investigate the degree and selectivity of rectal thromboxane inhibition by low dose aspirin and there by investigate the contribution of platelet thromboxane to rectal thromboxane.

METHODS

The study was a randomized double-blind placebo controlled crossover study. Twelve healthy volunteers were studied, each over four separate study periods with two weeks wash-out between each period. Changes in levels of thromboxane (TX) B2, prostaglandin (PG) E2 and leukotriene (LT) B4 in rectal dialysates were measured in response to 5 days oral low dose aspirin therapy in one of three once-daily formulations (plain 75 mg, plain 300 mg or enteric coated 300 mg), and compared to placebo. For each study period, rectal dialysates (4 h duration) were obtained at baseline and twice more after 5 days of aspirin or placebo therapy. Dialysate levels of thromboxane B2, leukotriene B4, prostaglandin E2, and serum thromboxane B2 were measured by radioimmunoassay.

RESULTS

Dialysate thromboxane B2 levels were consistently inhibited by low dose aspirin (overall results of all formulations, 75 to 300 mg daily) from 1.06 ng/ml (geometric mean, 95% CI: 0.79-1.43 ng/ml) on placebo, by 29% (95% CI: 11-40%) to 0.75 ng/ml (0.56-1.01 ng/ml) (P = 0.046) on aspirin. In the absence of aspirin the level of prostaglandin E2 was 1.47 ng/ml (0.97-2.23 ng/ml) and in the presence of aspirin was not significantly changed. The dialysate level of leukotriene B4 was 0.45 ng/ml (0.34-0.61 ng/ml) in the absence of aspirin and there was no significant change on low dose aspirin. Serum thromboxane was inhibited by 80% to 20% of placebo values by plain aspirin 75 mg, by 95% by plain aspirin 300 mg, and by 82% by enteric coated aspirin 300 mg, respectively (P < 0.01). These results show that 29% of the rectal thromboxane, but none of the rectal prostaglandin E2 or leukotriene B4 is inhibited by low dose aspirin. We infer that 34% of the rectal thromboxane B2 is platelet-derived in our volunteers.

CONCLUSION

Low dose aspirin will selectively inhibit a proportion of rectal thromboxane and may have prophylactic therapeutic potential in inflammatory bowel disease.

Treatment of inflammatory bowel disease from now to the millennium

After decades of therapeutic stasis, treatment advances are occurring in inflammatory bowel disease. Recognition that mesalazine was the active moiety of sulphasalazine has led to a number of new methods of delivering mesalazine without sulphapyridine, with improved toxicity ratios. Current attempts to deliver topical steroids directly to the large bowel have yet to be established as therapeutically effective. Immunosuppressive treatment has been used for many years but recent evidence has firmly established its value and cyclosporin has recently been added to the therapeutic armamentarium. Increasing understanding of the basic processes of inflammation has yielded targets for anti-inflammatory treatments aimed both at the processes of immune activation and of attraction by chemotaxis of neutrophils from the circulation to the lamina propria. Some of these novel treatments, which will be assessed in forthcoming years, involve large molecular weight bioengineered peptides and antibodies that are likely to be expensive and difficult to administer. Other treatment, e.g. 5-lipoxygenase or thromboxane synthesis inhibitors or platelet-activating factor antagonists, are conventional lower molecular weight compounds that are easier to produce and are orally active. It is predicted that 5-lipoxygenase inhibitors will be the next therapeutic advance in inflammatory bowel disease. Such a prediction may founder if blanket suppression of multiple inflammatory mechanisms, rather than targeted actions, is required in inflammation.

Roles of leukotriene B4, prostaglandin E2, and cyclic AMP in Campylobacter jejuni-induced intestinal fluid secretion

Infection of rabbit ileal loops with inflammatory Campylobacter jejuni strains caused elevation of cyclic AMP, prostaglandin E2, and leukotriene B4 levels in tissue and fluids. Incubation of cultured Caco-2 cells with loop fluids caused elevated cellular cyclic AMP levels, an effect which was inhibited by antiserum against prostaglandin E2.

Ranitidine bismuth citrate and aspirin-induced gastric mucosal injury

The aim of this study was to investigate the protective action of a new compound, ranitidine bismuth citrate, in the prevention of aspirin-induced acute mucosal injury to the upper gastrointestinal tract of healthy human volunteers. In a double-blind randomized three-way cross-over study 24 male volunteers received placebo, 900 mg aspirin or 900 mg aspirin and 800 mg ranitidine bismuth citrate at 12-h intervals for nine doses with a 2-week wash-out period between each treatment. The median (interquartile range) number of erosions seen at endoscopy when ranitidine bismuth citrate was given with aspirin (1 [0-4]) was significantly lower than aspirin alone (24 [16-32]) (P < 0.001) and not significantly different from either baseline or placebo (0 [0-2]). These findings were similarly reflected in the effects on microbleeding following the ninth dose: 12.1 (7.1-21.0) microL/10 min following aspirin alone compared to levels with placebo of 1.2 (0.4-2.9), and with aspirin and ranitidine bismuth citrate of 1.6 (0.8-2.6) (P < 0.005). Ranitidine bismuth citrate conferred substantial protection from aspirin-induced injury to the gastric and duodenal mucosa as determined by both endoscopic assessment and microbleeding rates, reducing injury to placebo levels.

In vivo rectal inflammatory mediator changes with radiotherapy to the pelvis

In vivo changes in the rectal values of eicosanoid inflammatory mediators induced by pelvic radiotherapy were measured to study the pathophysiology of the early radiation bowel reaction. Ten patients having pelvic radiotherapy, aged 57 to 78, had rectal dialysis. Values of the eicosanoids leukotriene B4 (LTB4), thromboxane B2 (TXB2), and prostaglandin E2 (PGE2) were measured before radiotherapy, at the end of radiotherapy, and at least four weeks after radiotherapy. Values of LTB4 rose with radiotherapy from 0.21 ng.ml-1 (median) to 1.14 ng.ml-1 (p = 0.012); PGE2 rose from 0.60 ng.ml-1 to 1.58 ng.ml-1 (p = 0.038), and TXB2 rose from 0.365 ng.ml-1 to 1.6 ng.ml-1 (p = 0.005). The rise in eicosanoid inflammatory mediators may have an important role in the pathophysiology of the early radiation bowel reaction.

Nitric oxide synthase activity in ulcerative colitis and Crohn's disease

Excessive nitric oxide (NO) production by an isoform of NO synthase that can be induced by inflammatory stimuli leads to changes in vascular permeability and to tissue injury. We measured NO synthase activities in mucosa and muscle from the colons of control patients (n = 11) and patients with ulcerative colitis (6) or Crohn's disease (4). NO synthase activity in colonic mucosa of ulcerative colitis patients was 0.55 (median interquartile range 0.32-0.57) nmol/min per g tissue, which was about eightfold higher than the value in control mucosa, with no individual overlap (p < 0.001). With colonic muscle there was no difference in NO synthase activity between ulcerative colitis patients and controls. In the patients with Crohn's disease, mucosal NO synthase activity did not differ from control values and activity in the colonic muscle was low. Thus, induction of colonic NO synthase may be involved in the mucosal vasodilation and increased vascular permeability of active ulcerative colitis, and could also contribute to the impaired motility that accompanies toxic dilation.

Ranitidine: differential effects on gastric bleeding and mucosal damage induced by aspirin

This study investigated the influence of ranitidine on mucosal injury and gastric bleeding in 20 normal volunteers taking 600 mg aspirin q.d.s. This study was a double-blind placebo controlled crossover study comparing ranitidine, as 150 mg b.d., 300 mg q.d.s. and 600 mg b.d. with placebo. Gastric mucosal injury was assessed at unsedated endoscopy by counting haemorrhagic and non-haemorrhagic erosions; bleeding was measured in gastric washings. Aspirin alone increased mucosal injury from 0 to 11.4 erosions (mean, P < 0.01) and bleeding from 1.77 to 9.11 microliters blood/10 min (mean P < 0.001). Ranitidine prophylaxis reduced bleeding to 5.34, 3.18 and 3.47 microliters/10 min with 150 mg b.d., 300 mg q.d.s. and 600 mg b.d. respectively (overall effect of ranitidine P < 0.001) and also reduced haemorrhagic erosions though it had no effect on the total number of erosions. Ranitidine is effective at reducing aspirin-induced gastric bleeding and whilst not reducing aspirin-induced gastric erosions, it does reduce the number that appear haemorrhagic. Ranitidine may have a role in the prophylaxis of aspirin-induced gastric bleeding.

New treatments in inflammatory bowel disease

Salicylates and steroids remain the mainstay of treatment for inflammatory bowel disease. New formulations which attempt to lower the rates of side effects are under evaluation. The value of azathioprine has been established in ulcerative colitis and cyclosporin has been shown to be of value. Dietary therapy in Crohn's disease has been the focus of a large amount of research and benefits have been demonstrated. New therapies including bioengineered drugs are anticipated.

Mechanisms of gastric and duodenal damage and protection

By binding to the cyclooxygenase enzyme, non-steroidal, anti-inflammatory drugs (NSAIDs) inhibit synthesis of prostanoids characteristic of the cell under consideration. For the gastric mucosa, the main products are prostaglandin (PG) E2 or PGI2; for platelets the main product is thromboxane. Aspirin irreversibly acetylates the cyclooxygenase enzyme. Consequently, it has more prolonged effects, particularly in cells like platelets, which are not rapidly turned over. Prostaglandin-dependent protective actions in the stomach and duodenum which are inhibited by NSAIDs include mucous and bicarbonate secretion, surface epithelial cell hydrophobicity and mucosal blood flow. Prostaglandins are also protective of the microvasculature and can increase the flux of water from serosa to mucosa, with possible dilution of injurious substances. Abrogation of these properties renders the mucosa more vulnerable to injury. In addition, salicylates have topical irritant properties. A number of repair mechanisms, including epithelial cell division and possibly angiogenesis, are prostaglandin dependent. As a consequence of these actions, acute damage and ulcers develop more easily and ulcers heal more slowly when individuals take NSAIDs. In some cases the anti-hemostatic effects of NSAIDs may be partly instrumental, and data in model systems have shown that aspirin and possibly piroxicam can enhance intragastric bleeding separately from their effects of mucosal injury. Smoking, which predisposes to peptic ulceration, also appears to reduce mucosal prostaglandin synthesis. Other predisposing factors such as age, sex and the ulcer diathesis have little effect. Some have found Helicobacter pylori to enhance leukotriene synthesis. We have shown that NSAIDs are also associated with increased leukotriene B4 as well as reduced prostaglandin synthesis in patients taking NSAIDs long term.

Separation of the impairment of haemostasis by aspirin from mucosal injury in the human stomach

1. An increasing body of data suggests that the antihaemostatic as well as the ulcerogenic actions of aspirin and other non-steroidal anti-inflammatory drugs may be operative when patients present with haematemesis and melaena. 2. We therefore developed methods to allow separate evaluation of the erosive and anti-haemostatic actions of aspirin in the human gastric mucosa. Volunteer subjects took 300 mg of aspirin daily in the morning or 600 mg of aspirin four times a day for 5 days under blinded randomized conditions. Changes in spontaneous gastric microbleeding, endoscopic signs of injury, spontaneous bleeding per gastric erosion, biopsy-induced bleeding and eicosanoids were studied. 3. Both doses of aspirin significantly inhibited gastric mucosal synthesis of prostaglandin E2 and reduced the serum thromboxane concentration. Erosions developed and regressed rapidly; compared with baseline 300 mg of aspirin daily in the morning caused substantial numbers of gastric erosions to develop (mean 5.3, 95% confidence limits 2.7-10.2) but this was significantly less than that caused by 600 mg of aspirin four times a day (10.9, 7.2-16.5, P less than 0.05). The presence of erosions was associated with enhanced spontaneous bleeding, but only during aspirin administration. 4. Aspirin significantly increased bleeding induced by mucosal biopsy and was associated with significant enhancements in the rate of bleeding per gastric erosion. Bleeding rate per erosion but not biopsy-induced bleeding showed a significant dose-related increase with 600 mg of aspirin four times a day. Enteric coating reduced endoscopic signs of injury, but did not affect the impaired haemostasis caused by aspirin.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin-induced gastric mucosal damage: prevention by enteric-coating and relation to prostaglandin synthesis

1. Gastric damage induced by low-dose aspirin and the protective effect of enteric-coating was assessed in healthy volunteers in a double-blind placebo-controlled cross-over trial using Latin square design. Each was administered placebo, plain aspirin 300 mg daily, plain aspirin 600 mg four times daily, enteric-coated aspirin 300 mg daily, or enteric-coated aspirin 600 mg four times daily for 5 days. Gastric damage was assessed endoscopically, and gastric mucosal bleeding measured. 2. Aspirin 300 mg daily and 600 mg four times daily caused significant increases in gastric injury compared with placebo. Gastric mucosal bleeding was significantly more with the high dose, with a trend towards increased gastric erosions, compared with the low dose. 3. Enteric-coating of aspirin eliminated the injury caused by low dose aspirin and substantially reduced that caused by the higher dose. 4. All dosages and formulations caused similar inhibition of gastric mucosal prostaglandin E2 synthesis. 5. Serum thromboxane levels were suppressed equally with plain and enteric-coated aspirin. 6. In this short-term study in healthy volunteers, gastric toxicity from aspirin was largely topical, independent of inhibition of prostaglandin synthesis, and could be virtually eliminated by the use of an enteric-coated preparation.

Fingertip injuries in rock climbers

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Allen-Spence repair for coronal and distal penile hypospadias with chordee

Our experience with the Allen-Spence procedure in 31 children with distal hypospadias is described. The surgical techniques and our results are reviewed and compared to those reported in the literature. This procedure is safe and simple, and provides excellent cosmetic and functional results.

Complications of partial cystectomy in patients with high grade bladder carcinoma

We herein analyze the results of partial bladder resection in 61 patients with stage A transitional cell carcinoma. Staging was based on preoperative evaluation, operative findings and postoperative microscopic study of the specimen. In 54% of the patients with high grade malignancies local recurrences were noted and the patients eventually died of the disease. There were no recurrences in patients with low grade tumors. Therefore, the grade of bladder carcinoma should be considered when patients are chosen for this operation.

Pheochromocytoma: recent experience with detection and management

Our experiences spanning a ten-year period have been reviewed with regard to pheochromocytoma. During this period 1,890 metanephrine excretion levels were performed; 91 of these were elevated. An over-all incidence of 1.9 per cent false positive studies was found. Factors contributing to the false positive studies are discussed. Fourteen patients had 15 pheochromocytomas resected. The presenting features, diagnosis, localization, preoperative and operative management, as well as the results are presented.

Congenital total hemihypertrophy and carcinoma of undescended testicle: a case report

The first case of germinal cell tumor of the testis in a patient with congenital total hemihypertrophy is reported. The literature is discussed with emphasis placed on the frequent association of hemihypertrophy with oncogenesis and teratogenesis. We conclude that because of the high incidence of malignancy in the undescended testis prophylactic orchiectomy should be considered in a patient with hemihypertrophy and cryptorchidism.

Capillary hemangioma of the male urethra: case report with literature review

The seventeenth case of hemangioma of the urethra is reported. A review of the literature supports our own experience that this growth tends to recur locally. It is our opinion that an initial wide resection should be performed. The margins of the removed lesion must be uninvolved or recurrence is almost certain.

Preureteric vena cava

Preureteric vena cava is a rare congenital anomaly usually presenting clinically with hydronephrosis and an "S or fishhook" deformity of the ureter at the third or fourth lumbar vertebrae. Unusual presentations do occur and can lead to misdiagnoses. Herein such a case originally diagnosed as a ureteropelvic junction obstruction is presented and the embryology reviewed.

Large prostatic hematomas associated with carcinoma of the prostate

Two cases are presented of large prostatic hematomas secondary to adenocarcinoma of the prostate. The similarity of these cases at examination to prostatic abscesses complicated diagnosis and delayed treatment. To avoid diagnostic error it is important to remain alert to this atypical presentation and to remember the necessity to obtain adequate biopsies.

Medical management of refractory hematuria in sickle-cell trait

Hematuria secondary to sickle-cell trait has on occasion proved refractory to medical management. We have adopted a new six-drug regimen to deal with this difficult problem. Herein is reported our experience with this protocol in 2 patients. Our results have been excellent, with hematuria clearing within twenty-four hours. The drug regimen is used in an attempt to alter the conditions that are favorable for sickling in the renal medulla.

Septic arthritis secondary to vesico-acetabular fistula: a case report

The second case of septic arthritis resulting from a vesico-acetabular fistula secondary to a penetrating injury is reported. Despite reported good results in blunt trauma with hip and urinary tract drainage combined with appropriate antibiotics, improvement occurred in our patient only after surgical excision of the fistulous tract. It appears that in some cases early fistulectomy can shorten hospital stay and reduce the incident of complete ankylosis.

The role of ultrasonics in the evaluation of renal masses

Analysis of our experience with echography in the evaluation of renal masses reveals an error rate of 31 per cent. Presently, this technique may be useful in directing the evaluation of a renal mass to either arteriography, if a tumor is suspected, or needle aspiration and renal cystogram, if a cyst is suspected. However, echography should not replace more definitive studies.

Cell-mediated immunity in renal cell carcinoma-preliminary report

The microcytotoxicity test was used in 8 cases post-nephrectomy for renal cell carcinoma to stage the disease clinically and to evaluate immunologically. Half of the patients had stage IV disease and half were believed to be cured clinically. Cell-mediated immunity and serum blocking factors were found in all patients with known metastases. However, cellular immunity was not found in 3 of the 4 remaining patients and serum blocking factors were also not noted in the 2 clinically cured patients who were tested. These findings are compatible with the facts that cell-mediated immunity and serum blocking factors are found when there is a grossly discernible antigenic source, that serum blocking factors are lost in patients who are clinically free of tumor and that in some patients who are clinically cured with a possible total loss of antigenic presence there is a disappearance of significant cell-mediated immunity.

The place of bone scan in the diagnosis of renal cell carcinoma

We herein review 12 cases of renal cell carcinoma evaluated by bone scan and skeletal survey. Comparison of these techniques revealed a high incidence of falsely negative results (42 per cent) when using skeletal survey alone. It is now our policy to include the bone scan in our initial evaluation of patients with renal cell carcinoma.

Aggressive surgery for renal cell carcinoma with ena cava tumor thrombus

Herein is presented what we believe to be the eighth case reported of renal cell carcinoma with caval tumor thrombus treated by radical excision with vena caval resection. A review of the literature reveals that although postoperative morbidity is minimal, only 1 patient survived more than two years. All patients with metastases at time of operation died within one year. It is our conclusion that the length and quality of survival anticipated must be carefully weighed before performing this major surgical procedure.

Experience with the thoraco-abdominal incision for nephroblastoma in children less than 3 years old

Our results with the routine use of a modified thoraco-abdominal incision in the treatment of patients with nephroblastoma are reported herein. We have used this incision successfully in 5 patients less than 3 years old and are impressed with the improved exposure. In our limited experience the thoracic extension has not adversely altered the operative or postoperative course.

Antigenic cross reactivity between benign prostatic hyperplasia and adenocarcinoma of prostate

Tissue cultures were established from biopsy specimens of adenocarcinoma of the prostate (ACP) and benign prostatic hyperplasia (BPH). Generally, peripheral blood lymphocytes from BPH and ACP patients were cytotoxic to both ACP and BPH cells, but not normal fibroblasts nor cells cultured from other types of malignant tissue. Peripheral blood lymphocytes from normal control patients or from patients with other types of cancer were not cytotoxic to ACP- or BPH-derived cells. These findings are consistent with a cross reactive autoimmune response in ACP and BPH patients, directed against a common antigen(s) present on both ACP and BPH cells.