Influence of volume of work on the outcome of treatment for patients with colorectal cancer

BACKGROUND

Recent recommendations for the reorganization of cancer services emphasize the importance of a 'minimal acceptable volume of work'. The influence of both hospital and surgical workload has been examined using a population-based series of patients with colorectal cancer.

METHODS

Nine hundred and twenty-seven patients with primary colorectal cancer diagnosed during the period 1 January to 30 June 1993 were identified from the North Western Regional Cancer Registry. Case notes were reviewed for information on patient age and sex, histological diagnosis, disease stage, degree of tumour differentiation, mode of admission, identity of operating surgeon, timing of operative procedure, and use of radiotherapy and/or chemotherapy. A multivariate Cox proportional hazards model was then constructed to examine, simultaneously, the effects of patient-, disease- and health service-related variables on survival.

RESULTS

Age, tumour stage and differentiation, and mode of admission were revealed as significant independent prognostic variables. After adjusting for these variables, neither operator grade (consultant versus junior), consultant workload nor hospital throughput were identified as independently influencing patient survival.

CONCLUSION

The results of this study do not support an association between volume of work and patient outcome.

Twenty-four hour access to a CD-ROM surgical database has educational and patient management benefits

This study determined whether 24 h access to current surgical literature via a personal computer CD-ROM was of relevance to the junior surgeon managing acute surgical referrals. Over a 2 month period, a total of 53 acute surgical referrals were assessed and initially managed by a single basic surgical trainee. The Medline database was searched using Silver Platter software for current surgical literature regarding aetiology and management after the initial patient assessment. Of the 53 searches made (mean search time 7 min 22 s), 20 (38%) were judged to have produced information that increased basic surgical trainee knowledge and a further 9 (17%) changed patient management. By contrast, 24 (45%) of searches did not reveal helpful information. The availability of a surgical database that provides the trainee with abstracts of the current literature is valuable both for the educational development of the surgeon and improvement of patient care.

Response of the parotid gland of the brushtail possum, Trichosurus vulpecula, to adrenergic stimulation

Adrenergic stimulation of parotid secretion was investigated in anaesthetised brushtail possums to ascertain fluid secretion rates and salivary composition. Because neither alpha- nor beta-adrenergic stimulation evoked saliva output, infusion of the adrenergic agonists was superimposed on a pre-existing bethanechol-stimulated flow. Isoprenaline infusion (2.4 nmol min-1) increased salivary amylase activity, [protein]; [HCO3]; [PO4] and [Ca], and amylase/Ca and protein/Ca ratios; reduced [Cl]; [K] and osmolality; but did not alter H+ activity; [urea]; [Na]; [Mg]; amylase/protein or saliva/plasma urea ratios. These data are consistent with isoprenaline stimulating acinar secretion of protein, Ca and PO4 but not the ion transport necessary for primary fluid formation at the endpieces and modifying transport of monovalent ions in the excurrent ducts. Consequently, the possum parotid has beta-adrenergic receptors in both the endpieces and excurrent ducts. Phenylephrine infusions at 2.4 and 24 nmol min-1 were without effect whereas phenylephrine at 240 nmol min-1 caused changes in salivary composition which paralleled those for isoprenaline administration but were generally of lesser magnitude. Thus, the possum parotid has few or no alpha-adrenergic receptors and the salivary response elicited was the result of cross-reaction of phenylephrine with beta-adrenergic receptors.

Telephone follow-up: an extension of the surgical outpatient department

A total of 112 surgical patients took part in telephone follow-up, conducted by non-medical staff, after discharge home. Successful telephone follow-up was achieved in 93% of patients at 6 weeks, 91% at 3 months and 79% at 12 months. Telephone follow-up by non-medical staff is a practical method of assessing patient outcome after surgery. Wider use of this technique would free up time in the surgical clinics, without compromising audits of outcome and purchaser demands for evidence of efficacy.

Opiate and sedative dependence predicts a poor outcome for patients receiving home parenteral nutrition

BACKGROUND

Home parenteral nutrition (HPN) is used to treat intestinal failure. A minority of HPN patients are dependent on opiates and benzodiazepines to control pain and anxiety. The aim of this study was to determine what effects such drug dependence had on patient outcomes.

METHODS

Ten dependent patients were prospectively compared with 10 well-matched, nondependent HPN patients for the same 12-month period. Episodes of line sepsis and other complications were documented and the cost of treatment estimated. Health status was measured using the SF36 and EuroQol instruments.

RESULTS

The dependent group had significantly more episodes of central line sepsis (p = .0007) as well as other complications (p = .0002). This led to significantly longer periods of inpatient care (p = .0004) and therefore higher costs of treatment. Health status was lower in the dependent group; they reported more pain (p = .04) and less energy (p = .04).

CONCLUSIONS

The complication rate and increased cost of treatment for opiate- and sedative-dependent patients receiving HPN significantly detract from the overall outcome of this therapy.

Inhibition of platelet deposition with local delivery of heparin using a double balloon catheter

Heparin is an effective agent in the treatment of unstable angina and myocardial infarction. The clinical utility of heparin is limited by bleeding complications. This study was performed to determine whether static delivery of heparin could effectively inhibit further platelet deposition. Thrombogenic graft segments were incorporated into chronic arteriovenous shunts in pigs. Autologous platelets were labeled with 111Indium. Platelet deposition was quantitated with gamma camera imaging. The grafts were exposed to blood flow for 15 min in order to induce platelet deposition on the thrombogenic surface. Heparin was delivered locally either by direct exposure or with a double balloon catheter. After a 15 minute exposure period, the heparin solution was removed and subsequent platelet deposition was monitored for 90 minutes. Heparin, administered with the double balloon catheter in doses as low as 12.5 U, effectively inhibited further platelet deposition. An intravenous injection of 100 U of heparin, the highest dose use for local delivery, did not perturb bleeding time or the activated partial thromboplastin time. In conclusion, platelet deposition can be inhibited with static local delivery of heparin at doses that are not associated with systemic bleeding.

Effect of intravascular irradiation on cell proliferation, apoptosis, and vascular remodeling after balloon overstretch injury of porcine coronary arteries

BACKGROUND

Ionizing radiation has been shown to reduce vascular lesion formation after balloon overstretch injury of pig coronary arteries. The present series of experiments examines the mechanism by which this occurs.

METHODS AND RESULTS

Balloon injury was performed on porcine coronary arteries, followed immediately by ionizing radiation using either a source train of 90Sr/Y or 192Ir seeds designed to deliver 14 or 28 Gy at a depth of 2 mm from the source. The animals were killed 3, 7, or 14 days after injury. Bromodeoxyuridine was administered 24 hours before euthanasia to label proliferating cells. Cell proliferation was significantly reduced on day 3 in the adventitia and media of the irradiated vessels compared with controls. Two weeks after injury, there were fewer alpha-actin-positive myofibroblasts in the adventitia of the irradiated vessels than in nonirradiated controls, and morphometric analysis indicated that the vessel perimeter of the irradiated vessels was significantly larger than in controls. Together, these results suggest a positive effect of intravascular irradiation on vascular remodeling. Apoptosis was estimated by terminal transferase dUTP-biotin nick-end labeling (TUNEL) 3 and 7 days after injury. TUNEL-labeled cells were found primarily in the adventitia at the medial tear, but no differences were detected between irradiated and control vessels.

CONCLUSIONS

These studies suggest that intracoronary radiation primarily inhibits the first wave of cell proliferation in the vessel wall and demonstrates a favorable effect on late remodeling by preventing adventitial fibrosis at the injury site.

Short- and long-term outcome of narrowed saphenous vein bypass graft: a comparison of Palmaz-Schatz stent, directional coronary atherectomy, and balloon angioplasty

Percutaneous treatment of saphenous vein graft (SVG) stenosis has been established as an alternative to repeat coronary artery bypass grafting. Intracoronary Palmaz-Schatz stent (PSS) and directional coronary atherectomy (DCA) have been suggested to provide better short- and long-term results than balloon angioplasty. Records of 840 patients with 931 SVG lesions treated with PSS (121 patients, 132 lesions), DCA (103 patients, 107 lesions), and balloon angioplasty (616 patients, 692 lesions) were reviewed. Inhospital and long-term outcome were compared among treated groups. The groups had similar clinical and angiographic baseline characteristics except for higher previously dilated grafts in the stent group and graft location among devices. Stent placement was angiographically successful in 99%, DCA in 95%, and balloon angioplasty in 93% of the lesions (p = 0.03). Quantitative angiography revealed a larger lumen diameter after procedure after PSS (3.2 mm) and DCA (3.1 mm) compared with 2.4 mm after balloon angioplasty (p = 0.0001). Angiographic complications (abrupt closure, severe dissections, or distal embolization) were evident in eight (6.1%) lesions after PSS placement, in 17 (15.9%) after DCA, and in 61 (8.8%) after balloon angioplasty. Serious in-hospital clinical complications (death, emergency coronary artery bypass grafting, or Q-wave myocardial infarction) were similar among devices. Survival rates were similar among the groups (p = 0.15). Repeat revascularization at follow-up was reported in 58 (60.4%) of patients after PSS, in 48 (51.1%) after DCA, and in 280 (49.4%) after balloon angioplasty. Correlates of additional revascularization at follow-up were older grafts, calcific lesions, previously dilated grafts, longer lesions, and patients with lower ejection fractions (odds ratio 1.06, 1.34, 1.43, 1.04, and 1.01, respectively). Correlates of mortality rate at follow-up were older patients, patients with lower ejection fractions, and distal embolization (odds ratio 1.04, 1.04, and 1.92, respectively). These data suggest that in patents with SVG stenosis the initial success and morbidity rates are similar when comparing PSS and DCA with balloon angioplasty. Although a larger lumen is obtained with PSS and DCA, patients who underwent balloon angioplasty had similar rates of cardiac events and requirements for additional procedures at follow-up.

Repeated oestrus synchrony and fixed-time artificial insemination in beef cows

The feasibility of breeding spring-calving, single-suckled beef cows without the use of natural service was investigated over two breeding seasons by using repeated oestrus synchrony and fixed-time artificial insemination (AI). Initially, cows were oestrus-synchronised with subcutaneous norgestomet implants inserted for 10 days, with an injection of prostaglandin before the implants were removed. The cows were inseminated once 56 hours after the implants were removed, and 12 days later they were re-treated with norgestomet implants to allow a second synchronised service. Twenty-one days after the first synchronised AI, milk samples were taken for progesterone assay and the norgestomet implants were removed. The cows received a second service 56 hours later if the 21-day milk progesterone assay suggested that they were not pregnant. All the cows receiving a second service were retreated with norgestomet implants to allow a third synchronised service as necessary. Pregnancy was later confirmed by rectal palpation. In the first year, 48 cows entered the programme and the pregnancy rates to the first, second and third synchronised services were 56, 69 and 40 per cent, respectively, with 17 per cent of cows barren at the end of the breeding period. In the second year, 69 cows entered the programme and the pregnancy rates were 58, 48 and 33 per cent to the successive services with 20 per cent of cows barren at the end of the breeding period. The accuracy of milk progesterone assay for pregnancy diagnosis was 84 per cent and 87 per cent in the first and second years, respectively.

Expression of nonmuscle myosin heavy chain-B isoform in the vessel wall of porcine coronary arteries after balloon angioplasty

Nonmuscle myosin heavy chain-B isoform (NMMHC-B) is expressed by proliferating vascular smooth muscle cells (SMCs), and its expression in primary lesions has been proposed to be predictive of restenosis after atherectomy. The present study was designed to study the time-course expression of NMMHC-B after angioplasty of porcine coronary arteries by in situ hybridization and immunohistochemistry. Domestic juvenile swine underwent percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending and circumflex coronary arteries with standard clinical angioplasty catheters. To identify proliferating cells, 5'-bromo-2'-deoxyuridine (BrdU) was administered and detected by immunohistochemistry on serial sections. Vessels were examined at 3, 7, and 14 days after balloon angioplasty, and uninjured coronary vessels were used as controls. Normal arteries showed hybridization to 35S-labeled NMMHC-B riboprobes localized mainly in the medial layer. NMMHC-B expression in the adventitia was markedly increased 3 days after balloon angioplasty. Seven and 14 days after injury, NMMHC-B mRNA-containing cells were localized in the adventitia and neointima at the arterial injury site. Cell proliferation, as indicated by BrdU staining, colocalized with NMMHC-B mRNA expression 3 and 7 days after angioplasty. These data indicate that cells proliferating in the adventitia and neointima express NMMHC-B; however, its expression is not limited to the proliferative state, since NMMHC-B mRNA was also found in quiescent SMCs of normal coronary arteries and in nonproliferating adventitial and neointimal cells 14 days after angioplasty.

Successful management of external duodenal fistula in a specialized unit

BACKGROUND

High-output external duodenal fistula remains a challenging condition to treat. Despite advances in metabolic and nutritional care, mortality rates remain high.

METHOD

Retrospective casenote review of patients managed on a specialised unit.

RESULTS

Thirteen of 388 admissions (3.4%, 11 males, median age 51 years) had an external duodenal fistula. Management was by eradication of abdominal and systemic sepsis and maintenance of nutritional status by the administration of total parenteral nutrition. The majority of fistulas followed surgery for peptic ulcer disease. Eight of 13 fistulas closed spontaneously, and of those requiring operative closure, surgery was successful in 4 of 5 cases. There were 2 mortalities.

CONCLUSION

High-output external duodenal fistula may be successfully managed in a specialised unit.

Surgical treatment of acute manifestations of Crohn's disease during pregnancy

When requiring surgery, acute exacerbations of Crohn's disease in pregnancy have been reported to carry high maternal and fetal mortality. We report six cases. The women presented at 30, 28, 12, 11, 31 and 25 weeks' gestation and all proved to have intraperitoneal sepsis. In three, the acute symptoms were the first indication of Crohn's disease. All the women recovered and five had healthy babies; the other had a miscarriage when a colonic anastomosis dehisced. In pregnant women with Crohn's disease, the indications for surgery are the same as in non-pregnant patients. For acute manifestations we recommend removal of the source of the sepsis and exteriorization of the bowel ends.

The role of the adventitia in the arterial response to angioplasty: the effect of intravascular radiation

PURPOSE

In the current series of experiments we have characterized cell proliferation leading to vascular lesion formation in a porcine model for post-angioplasty restenosis and examined the mechanism of action of intravascular beta irradiation in the prevention of lesion formation in this model.

METHODS AND MATERIALS

Juvenile male pigs were subjected to balloon overstretch injury of the left anterior descending and circumflex coronary arteries using clinical angioplasty catheters. Proliferating cells were labelled by injections of 50 mg/kg of bromo-deoxyuridine (BrDU) 24, 16 and 8 hrs prior to sacrifice and were detected by immunohistochemistry using a specific antibody to BrDU. In some cases, BrDU was given as a pulse 3 days after angioplasty and the animals sacrificed on day 14 to follow the migration of the cells which had proliferated earlier. Characterization of the proliferating cells was performed by immunohistochemistry using antibodies to specific cytoskeletal proteins specific for smooth muscle cells and myofibroblasts. Some vessels were treated at the time of angioplasty with 14 or 28 Gy (to a depth of 2 mm) intravascular irradiation using a flexible catheter with a pure beta emitter 90 SR/Y and the effect on cell proliferation and terminal transferase-mediated UTP nick-end labelling (TUNEL) examined 3 or 7 days later.

RESULTS

The first major site of cell proliferation between 2-3 days after angioplasty is the adventitia and not the medial wall. Seven days after angioplasty cell proliferation is predominant in the neointima and is reduced in the media and adventitia. Differential staining with antibodies directed against smooth muscle alpha actin and other cytoskeletal proteins indicates that the proliferating adventitial cells are myofibroblasts. Pulse label studies with BrDU indicates that the proliferating adventitial myofibroblasts migrate into the neointima and contribute to the mass of the restenosis lesion. Fourteen days after angioplasty the myofibroblasts in the neointima and the adventitia express alpha smooth muscle actin and form a fibrotic scar in the adventitia surrounding the injury site. Endovascular irradiation appears to inhibit development of the restenosis lesion by significantly reducing cell proliferation in the media and adventitia at early time points after injury. There were no significant differences in the percent of TUNEL labelled cells in the irradiated vessels compared to controls. Alpha actin staining of myofibroblasts in the adventitia was reduced in the irradiated vessels suggesting a positive effect of intravascular irradiation on vascular remodeling.

CONCLUSIONS

These studies have shown that adventitial myofibroblasts contribute to the problem of post-angioplasty restenosis by proliferating, forming a fibrotic scar surrounding the injury site, and migrating into the neointima. We hypothesize that the adventitial fibrosis which develops at the injury site contributes to negative vascular remodeling associated with clinical restenosis. Experiments in which vessels were exposed to intravascular irradiation at the time of angioplasty indicate that this treatment reduces post-angioplasty restenosis by inhibiting early cell proliferation in the media and adventitia and by preventing the fibrotic changes in the adventitia without a corresponding increase in cellular death or apoptosis in these tissues.

Local intracoronary heparin delivery with a microporous balloon catheter

Arterial thrombosis plays a major role in the pathogenesis of acute coronary syndromes such as unstable angina and acute myocardial infarction. Heparin is efficacious in treating both disorders; however, systemically administered heparin is associated with bleeding complications. Local intracoronary delivery of heparin may be a safer, more effective method of administration. This study was performed to determine the fate of heparin infused with a specially designed catheter for local intracoronary delivery. To quantitate heparin delivery, tritiated-labeled heparin was dissolved in a solution of unlabeled heparin (1,000 U/ml). A microporous balloon catheter was placed in the left anterior descending (LAD) and left circumflex arteries of anesthetized pigs (n = 15), and 1 ml of the heparin solution was infused. The animals were euthanized within 1 hour, and the treated arteries and controls were harvested, processed, and the tritiated activity was measured. To assess the distribution of the heparin in the arterial wall, 1 ml of fluorescein-isothiocyanate (FITC)-labeled heparin was locally delivered into the walls of the LAD and left circumflex arteries with the microporous balloon catheter. To visualize the dynamic fluid transfer of the device, a microporous balloon catheter was inflated in the LAD, and 1 ml of diluted contrast medium was infused under cinefluoroscopy. The arteries treated with tritiated-labeled heparin contained 0.6% +/- 0.2% of the infused heparin dose. Control arteries contained 0.01% of the administered heparin. Animals that were infused with FITC-labeled heparin displayed fluorescence throughout all layers of the artery, especially in the adventitia. In animals that were injected with 1 ml of diluted contrast medium through the microporous balloon, a relatively large amount of the infusate appeared in the arterial lumen proximal to the balloon. In conclusion, these results suggest that heparin can be delivered to coronary arteries with a microporous balloon catheter. However, <1% of the infused dose can be found in the artery 1 hour after delivery. Infused heparin is distributed throughout the arterial wall, but most of the infused solution appears in the arterial lumen proximal to the inflated balloon and is probably washed downstream after balloon deflation.

Potential role of the adventitia in arteritis and atherosclerosis

The role of the adventitia in vascular lesion formation has been largely ignored despite numerous studies which have suggested its potential importance. Adventitial reactions are common in atherosclerosis as well as arteritis. Experimental hypercholesterolemia in pigs and non-human primates stimulates the accumulation of inflammatory cells in the arterial adventitia. The extent of adventitial inflammation associated with human atherosclerotic plaques is correlated with the severity of intimal disease. Adventitial reactions also occur after balloon angioplasty. Our studies indicate that the major site of cell proliferation after angioplasty of porcine coronary arteries is the adventitia and not the medial wall. These cells have been identified as myofibroblasts on the basis of differential staining with smooth muscle specific antibodies and a role for these cells in arterial remodeling associated with angioplasty and late lumen loss is postulated. Evidence from pulse studies with bromodeoxyuridine suggests that adventitial myofibroblasts have the capacity to migrate into the forming intimal lesion after angioplasty and may be a major component of the neointima. Additional work will have to be directed at a more detailed examination of the response of adventitial cells to balloon injury and in the setting of atherosclerosis and arteritis to determine what role these cells might play vascular lesion development.

Identification of a potential role for the adventitia in vascular lesion formation after balloon overstretch injury of porcine coronary arteries

BACKGROUND

In the present series of experiments, we examined the onset of cell proliferation and growth factor expression after balloon overstretch injury to porcine coronary arteries.

METHODS AND RESULTS

Domestic juvenile swine underwent balloon overstretch injury to the left anterior descending and circumflex coronary arteries with standard percutaneous transluminal coronary angioplasty balloon catheters. To identify proliferating cells, 5-bromo-2-deoxyuridine (BrDU) was administered over a period of 24 hours before the animals were killed at either 1, 3, 7, or 14 days after injury. Immunohistochemistry was performed with monoclonal antibodies to BrDU and smooth muscle cell markers. Three days after injury, a large number of proliferating cells were located in the adventitia, with significantly fewer positive cells found in the media and lumen. Seven days after injury, proliferating cells were found primarily in the neointima, extending along the luminal surface. In situ hybridization for PDGF A-chain and beta-receptor mRNAs revealed that the expression of these two genes was closely correlated with the sites of proliferation at each time point. Studies in which BrDU was injected between days 2 and 3 and the animals were killed on day 14 suggested that the proliferating adventitial cells may migrate into the neointima.

CONCLUSIONS

These data suggest that adventitial myofibroblasts contribute to the process of vascular lesion formation by proliferating, synthesizing growth factors, and possibly migrating into the neointima. Increased synthesis of alpha-smooth muscle actin observed in the adventitial cells after arterial injury may constrict the injured vessel and contribute to the process of arterial remodeling and late lumen loss after angioplasty.

Randomized comparison of flexible versus nonflexible femoral sheaths on patient comfort after angioplasty

Patients who undergo percutaneous transluminal coronary angioplasty (PTCA) by the femoral approach are usually required to lie flat in bed for 6 to 24 hours, which may result in significant discomfort. This study was performed to evaluate the safety and benefit of a flexible sheath that enables patients to sit at a 60-degree angle while the sheath is in place in the femoral artery. Sixty patients were randomly assigned to receive either flexible or nonflexible sheaths before PTCA. Patients with flexible sheaths were allowed to sit at an angle of 60 degrees after the procedure. Heparin management was the same in both groups. Frequency of calls to nurses for back pain was recorded for both groups. For analgesia, nalbuphine was administered in 2-mg increments. All sheaths were removed the day after the procedure. Femoral ultrasound was used to detect groin complications (hematoma, pseudoaneurysm, or arteriovenous fistula) and was performed in all patients. Baseline characteristics were similar in both groups. There were no differences in ease of sheath insertion or guide catheter movement through the sheaths. The arterial pressure waveform was not dampened in any of the flexible sheath patients while in the sitting position. Patients with flexible sheaths had fewer calls for back pain and required less nalbuphine than patients with nonflexible sheaths. Groin complications were similar in both groups. In conclusion, by allowing patients to sit up to an angle of 60 degrees, flexible sheaths have a beneficial effect in reducing back pain and the need for analgesics after PTCA.

"Bailout" coronary stenting in patients with a recent myocardial infarction

Patients who underwent bailout intracoronary stenting within 7 days of a myocardial infarction had lower clinical and angiographic success rates and a higher incidence of emergent coronary artery bypass graft surgery than patients who underwent bailout stenting without a history of a recent myocardial infarction. In addition, there was a trend toward more cardiac events after discharge in patients who received stents after a recent myocardial infarction.

Management of intra-abdominal abscesses in Crohn's disease

Over a 5-year period, 54 intra-abdominal abscesses were observed in 40 (20.8%) of 192 patients with Crohn's disease. The median age was 39 years (range 17-76 years); median interval from diagnosis, 7.5 years (range 0-24 years) and the median number of surgical operations was 2 (range 0-7). Forty abscesses (74.1%) were spontaneous and 14 (25.9%) were postoperative. Thirty abscesses were initially managed by laparotomy, 14 by percutaneous drainage, nine by incision and drainage and in one case the abscess drained spontaneously. Intra-abdominal abscesses were managed successfully by laparotomy in 23 (76.7%) of 30 patients, with a 93% success rate (13 of 14) for spontaneous abscesses managed by resection and primary anastomosis. Three of 8 (37.5%) spontaneous abscesses were managed successfully by percutaneous drainage, a temporising effect being achieved in a further two cases. There was no significant difference in sepsis score or duration of hospital stay for patients managed initially by laparotomy and those managed by drainage. However, patients with stricturing or fistulating Crohn's disease were much more likely to have initial management by laparotomy and in these patients surgical intervention was found to be an effective initial strategy.

The influence of acoustic impedance mismatch on post-stenotic pulsed-Doppler ultrasound measurements in a coronary artery model

Acoustic impedance mismatch at the fluid-wall interface was shown to affect the spectra from an intravascular Doppler device in an in vitro model with a diameter typical of human coronary arteries. Measurements were obtained first under Poiseuille flow conditions with impedance mismatches of 0%, 7% and 12%, and then under stenosed conditions for the 0% and 7% mismatch cases. For the zero mismatch case, the Doppler spectra could be readily interpreted in terms of fluid mechanical phenomena. When mismatch was present, the spectra from Poiseuille flow exhibited multiple peaks which could not be directly related to the velocity profile. Also, the spectra from stenosed flow with a mismatch of 7% were similar to those from the zero mismatch case but did not exhibit the specific flow-related features as clearly. These results indicate that the impedance mismatch alters the acoustic environment inside the model and that this causes artifact in the Doppler spectra.

Inhibition of platelet-dependent thrombosis by local delivery of heparin with a hydrogel-coated balloon

BACKGROUND

Systemic administration of heparin can decrease mortality and morbidity of acute ischemic coronary syndromes such as unstable angina and myocardial infarction. Hemorrhage is the major limiting factor in the clinical use of systemic heparin. The objective of the present study was to determine whether local delivery of heparin could inhibit platelet-dependent thrombosis without altering systemic bleeding parameters.

METHODS AND RESULTS

Hydrogel-coated angioplasty balloon catheters were dipped in a heparin solution, dried, and applied to a platelet-rich mural thrombus in a chronic ex vivo porcine arteriovenous shunt. 111In-labeled platelet deposition was quantified by gamma camera imaging. In a separate series of experiments, 3H-heparin was used to estimate the amount of heparin delivered to the thrombus with the coated balloon. Systemic heparin administration produced a dose-dependent decrease in platelet-dependent thrombus formation that was maximal at 200 units/kg. Bleeding times and activated partial thromboplastin times were prolonged at this dose. An equal inhibition of thrombus formation was achieved after the coated balloon was dipped in a heparin solution (10,000 units/mL) and deployed at the mural thrombus. In contrast to systemic heparin administration, there was no alteration in bleeding parameters associated with local heparin delivery. The estimated amount of heparin delivered with the coated balloon was 40 units.

CONCLUSIONS

Local delivery of heparin in amounts sufficient to inhibit platelet-dependent thrombosis can be accomplished with a hydrogel-coated coronary angioplasty balloon catheter. Local heparin delivery can inhibit thrombus formation in amounts that are several orders of magnitude lower than the required systemic dose. Local delivery of heparin was not associated with prolongation of bleeding parameters.

Effect of lateral sphincterotomy on internal anal sphincter function. A computerized vector manometry study

PURPOSE

This study was designed to investigate the effect of lateral sphincterotomy on internal anal sphincter function in patients with chronic anal fissure.

METHODS

Using an eight-channel perfusion catheter and computerized data analysis, a prospective manometric study was performed on patients with chronic anal fissure undergoing lateral sphincterotomy (LS).

RESULTS

Mean resting pressure (MRP) in patients with anal fissure (85.1 mmHg) was significantly higher (P = 0.012) than control subjects (63.3 mmHg). One week following LS there was a significant reduction in MRP (50.0 mmHg; P = 0.0014), and this was maintained when reassessed five weeks later (MRP = 56.4 mmHg; P = 0.0019). There was no significant difference in coefficient of variation (a measure of the degree of manometric asymmetry of the anal canal) in the control group (mean, 8.9 percent) and in patients with anal fissure (mean, 7.7 percent; P = 0.43). LS created a significant increase in anal canal resting manometric asymmetry when assessed at one (mean, 17.3 percent; P = 0.0013) and six weeks (mean, 11.7 percent; P = 0.027) after the procedure.

CONCLUSION

LS produces a global and symmetric decrease in anal canal resting pressure. In addition, it produces a significant increase in manometric asymmetry of the resting anal canal by creating a detectable segmental defect.

Management aspects of induced twinning in beef suckler cows using in vitro fertilised embryos

Twin and single pregnancies were induced in two groups of oestrus-synchronised beef cows by using a combination of artificial insemination and the transfer of in vitro fertilised (IVF) embryos. Single IVF embryos transferred non-surgically to the uterine horn contralateral to the corpus luteum of 43 previously inseminated cows resulted in a calving rate of 72 per cent with a twinning rate of 38.7 per cent. In 45 cows, two IVF embryos were transferred non-surgically to one uterine horn resulting in a calving rate of 51.1 per cent with a twinning rate of 39.1 per cent. The median gestation length for cows bearing twins was 10 days shorter than that of cows bearing single calves (P < 0.001). The proportions of cows that received assistance at calving were similar for twin and single births (57 per cent vs 45 per cent, P > 0.05), but the incidence of retained fetal membranes was much higher after the birth of twins (62 per cent vs 3 per cent, P < 0.001). Nineteen per cent of twin calves were stillborn compared with 6 per cent of single calves (P > 0.05). The median birthweight of the twin calves was 32 kg (68 per cent of the median weight of single calves). The nutrition of twin-bearing cows in late pregnancy was adequate when assessed in terms of their plasma glucose, non-esterified fatty acid and beta-hydroxybutyrate concentrations. Serum immunoglobulin concentrations were similar in single and twin calves suggesting that the passive transfer of antibody was not compromised in the twin calves.

Seeding of intracoronary stents with immortalized human microvascular endothelial cells

Intracoronary stents are effective in decreasing the complications associated with acute closure during coronary angioplasty. A major complication associated with the use of coronary stents is acute thrombotic occlusion. It has been postulated that the stent loses its thrombogenic potential after it becomes covered with a layer of endothelial cells. Human dermal microvascular endothelial cells were transfected with a plasmid containing the simian virus 40 large T-antigen gene. Stents were placed in culture media with cells for 2 weeks. Seeding efficiency of the stent with the endothelial cells was assessed by scanning electron microscopy. Balloon-expandable coronary stents placed in cell culture with immortalized human microvascular endothelial cells showed near-complete coverage after 2 weeks. After balloon inflation, persistence of cells on the stent was noted only on the lateral aspect of the balloon-expanded stents. If these stents were placed in culture, complete recovery of the monolayer was noted after 3 days. Stents were then covered with endothelial cells and frozen for 4 days. After thawing, the cells adhered to the devices and divided to form a monolayer in tissue culture. Seeded balloon-expandable stents were frozen for 4 months, thawed, and then implanted in a pig coronary artery. Human endothelial cells were identified on the stent 4 hours after deployment. These studies demonstrate the feasibility of using a human microvascular endothelial cell line to seed an uncoated metal stent. The cells remain adherent to the stent, are functional after freezing, and remain on the stent at least 3 hours after intracoronary implantation.

Comparison of the thrombogenicity of stainless steel and tantalum coronary stents

This study was designed to compare the thrombogenicity of stainless steel and tantalum coronary stents of the same design. Stainless steel and tantalum coronary stents are being evaluated for their utility in treating acute closure and restenosis. A major disadvantage of stainless steel stents is radiolucency. To determine whether radioopaque tantalum stents may be safely substituted for stainless steel stents, we compared the relative thrombogenicity of these materials in stents of identical design. Total platelet and fibrin deposition on the stents were determined from measurements of indium 111-labeled platelet and iodine 125-labeled fibrinogen accumulation after deployment into exteriorized chronic arteriovenous shunts in seven untreated baboons. In another series of experiments, 111In-platelet deposition was compared 2 hours after stent implantation in coronary arteries of pigs. In baboons, platelet thrombus formation on stainless steel and tantalum stents was equivalent and plateaued at approximately 2.5 x 10(9) platelets after 1 hour (p > 0.05). Fibrin deposition averaged approximately 1 mg/stent and did not differ between the stainless steel and tantalum stents (p > 0.05). In the porcine coronary model there was no significant difference in 111In-labeled platelet deposition between the stainless steel and tantalum stents (p > 0.05). This result was confirmed by scanning electron microscopic analysis of the coronary stents. Based on these two models, we conclude that there is no significant difference in the thrombogenicity of stainless steel and tantalum wire coil stents.

Distal embolization is common after directional atherectomy in coronary arteries and saphenous vein grafts

Coronary embolization is a complication of coronary intervention procedures. The incidence, predictors, and clinical significance of this phenomenon during directional atherectomy were examined in 111 consecutive patients who underwent directional atherectomy to 120 lesions. Distal embolization occurred in 31 (28%) of the patients. It was noted mainly in the saphenous vein graft group of patients (12 [48%] of 25) versus the native coronary group (19 [22% of 86]; p = 0.01). Clinical predictors were age and de novo lesions. Morphologic predictors were larger artery size, larger postprocedure minimal luminal diameter, calcific lesions, and type C lesions. The only difference in clinical outcome was a longer hospitalization in the distal embolization group with 3.9 +/- 3.7 days versus the rest of the patients 2.4 +/- 2.4 days (p = 0.01). In the majority of patients there was no significant adverse clinical outcome.

Risk factors in patients presenting as an emergency with colorectal cancer

Of 905 patients with colorectal cancer admitted to a single district general hospital, 272 (30 per cent) were admitted as emergencies. Emergency patients had more advanced tumours (Dukes stage B and C 96 per cent versus 88 per cent of those admitted electively, P < 0.006), a shorter history (median 3 versus 11 weeks, P < 0.0001), were less likely to be fully ambulatory (44 versus 80 per cent, P < 0.0001) and more likely to have abdominal pain (74 versus 51 per cent, P < 0.001) and vomiting (40 versus 10 per cent, P < 0.0001). More emergency patients were given stomas (56 versus 35 per cent, P < 0.0001) and died in hospital (19 versus 8 per cent, P < 0.0001). Of those who survived to be discharged, patients admitted as an emergency spent longer in hospital (median stay 16 versus 13 days, P < 0.0001) and had a poorer overall 5-year survival rate (29 versus 39 per cent, P = 0.0001). Emergency patients were significantly older (median 74 versus 72 years, P = 0.04) and much more likely to be widowed (41 versus 27 per cent, P = 0.0002) than those admitted for elective surgery. If the personal and resource disaster of emergency colorectal cancer admission is to be reduced, screening strategies targeted by demographic characteristics require investigation.

Seeding of vascular grafts with an immortalized human dermal microvascular endothelial cell line

Small-caliber vascular grafts (< 6 mm) for arterial bypass frequently fail owing either to acute thrombosis or long-term fibrosis. One strategy to enhance patency is the coverage ("seeding") of luminal polymeric graft surfaces with endothelial cells (EC), which may in themselves be thromboresistant and antiproliferative, or which could be transfected with genes whose products are thrombolytic or growth-inhibitory. Advances in understanding of EC-biomaterial interaction have led to improvements in cell coverage and retention, but the sources of EC for such procedures have been limited to large vessels (autologous veins) and microvascular endothelium isolated from autologous adipose tissue. Before the practice of graft seeding can gain widespread clinical acceptance, the practical constraints of EC harvest, EC culture, and quick access to the seeded prosthesis for the surgical procedure must be overcome. Ideally, an EC line with a high proliferative capacity could be preestablished on the grafts, which could then be cryopreserved and made available as needed. The authors have seeded Dacron graft material with an immortalized human dermal microvascular EC line, HMEC-1. These cells were initially transfected with simian virus 40A large T antigen and have been passaged more than 100 times without signs of senescence. They also express von Willebrand factor, take yp acetylated low density lipoproteins, and rapidly form tubes when cultured on matrigel. Confluent coverage of Dacron graft segments, either untreated or coated with gelatin, was achieved in two weeks. The cells formed a monolayer over topographically elevated regions or appeared to be > one layer thick in other areas. Cells were also shown to remain viable after freezing.2+These results suggest a potential practical method for

Anastomotic configuration does not affect recurrence of Crohn's disease after ileocolonic resection

The influence of anastomotic configuration on recurrence of symptomatic Crohn's disease has been assessed in a sequential study of patients undergoing resection of ileal Crohn's disease. Between 1972 and 1991 92 patients had 102 ileocolonic anastomoses constructed after resection of intestinal Crohn's disease. The configuration of the ileocolonic anastomosis was either end to side (ES, n = 68) or side to side (SS, n = 34). The majority of patients in both groups were female and both groups were similar for duration of Crohn's disease at resection, steroid therapy, previous number of intestinal resections, indication for surgery and length of ileum resected at operation. No anastomotic leak occurred in either group. A total of 39 patients developed symptomatic recurrent Crohn's disease including 31 (46%) in the ES group and 8 (24%) in the SS group. This difference was related to the length of follow-up, the annual rate of symptomatic recurrence was almost identical for both end to side (0.066) and side to side (0.052) anastomoses.

Catheter-related morbidity in patients on home parenteral nutrition: implications for small bowel transplantation

Until recently, Home Parenteral Nutrition (HPN) has been the only real option for patients with intestinal failure. Small bowel transplantation (SBT) is advancing rapidly, however, and may soon provide an alternative for these patients. One of the arguments in favour of SBT is the alleged morbidity of prolonged parenteral nutrition. We have assessed the catheter-related morbidity in a large cohort of patients on HPN. A total of 88 central venous catheters were required in 50 patients. The main complications were sepsis (24 episodes) and occlusion (18 episodes). The overall incidence of catheter-related morbidity was one episode per 46 patient-months of HPN.

Reconstructive abdominal operations after laparostomy and multiple repeat laparotomies for severe intra-abdominal infection

Between 1980 and 1993, 18 patients underwent formal laparotomy after laparostomy and healing of the peritoneal cavity by granulation. The majority (12 patients) were men and the median age was 47 (range 22-67) years. Intraabdominal infection following surgery for Crohn's disease (four patients) and necrotizing pancreatitis (six) was the most common primary condition requiring laparostomy. A total of 23 reconstructive operations were carried out on the 18 patients a median of 6 (range 1-18) months after laparostomy. The indication for surgery was for closure and/or resection of an enteric fistula in 13 patients. The site of the fistula included three gastric, two duodenal, 11 small bowel and seven colonic. A further four patients required operation for closure or refashioning of a stoma. Five patients subsequently required a second laparotomy: two for elective restoration of bowel continuity, two for recurrent fistula and one for an acute abdomen. After reconstructive surgery following laparostomy 16 patients were discharged home alive and well, one requiring home parenteral nutrition for short bowel syndrome. In contrast, the two oldest patients in the series died from multiple organ failure immediately after initial reconstructive surgery. Both had pre-existing medical problems and in neither was there evidence of further intra-abdominal infection after reconstruction.

Local delivery of an antithrombin inhibits platelet-dependent thrombosis

BACKGROUND

Platelet-dependent thrombosis can be effectively inhibited by intravenous administration of direct thrombin antagonists. However, an increased propensity for abnormal bleeding has been associated with systemic administration of these agents. The goal of this study was to determine whether local delivery of a potent thrombin inhibitor, D-Phe-L-Pro-L-Arg chloromethyl ketone (PPACK), could inhibit platelet-dependent thrombosis without altering systemic hemostatic function.

METHODS AND RESULTS

Thrombus formation was measured by quantitative imaging of 111In-labeled platelet deposition on segments of thrombogenic vascular graft interposed in arteriovenous shunts in a porcine model. Intravenous administration of PPACK inhibited platelet deposition at a dose of 12.5 micrograms/kg per minute, which was associated with significant prolongations of both template bleeding times and activated partial thromboplastin times. By contrast, local infusion of PPACK at a dose of 0.02 micrograms/kg per minute (ie, a 600-fold smaller dose) into the fluid boundary layer at the interface between flowing blood and the thrombogenic segment produced equivalent inhibition of platelet deposition without prolonging either the bleeding time or the activated partial thromboplastin time. In addition, static exposure of a mural thrombus to solutions of PPACK at concentrations > or = 2.5 mg/mL for 15 minutes produced sustained inhibition of platelet-dependent thrombosis with no change in hemostatic measurements.

CONCLUSIONS

These results indicate that local delivery of the direct antithrombin PPACK, by either boundary layer infusion or static application techniques, effectively inhibits platelet-dependent thrombosis at doses that are several orders of magnitude less than the systemic dose required for an equivalent antithrombotic effect. In contrast to the systemic administration of PPACK, local delivery produced maximal inhibition of thrombosis without alterations in hemostasis.

Efficacy and safety of using perfusion dilatation catheter as initial balloon in coronary angioplasty

The efficacy and safety in using a new low-profile perfusion balloon catheter (PBC) as the initial balloon in percutaneous coronary angioplasty (PTCA) was assessed retrospectively in 61 patients: 43 males, mean age 62 +/- 12 years. Thirty-three patients (54%) had unstable angina. PTCA was performed using an improved PBC in the following vessels: LAD 40%; CX 21%; RCA 24%. Lesion morphology was: Type A 21%; Type B1 18%; Type B2 40%; Type C 21%. Mean artery size was 3.01 +/- 0.53 mm. Mean PBC size was 3.14 +/- 0.45 mm. The mean number of inflations used was 2.85 +/- 2.0. The mean longest inflation was 415 +/- 213 sec and the total inflation time was 663 +/- 342 sec to a mean maximum pressure atmosphere of 7.85 +/- 2.0 bars. The number of balloons used per procedure was 1.2 +/- 0.44. In 50 patients (82%) only one balloon was used during the PTCA. PTCA was successful (< 50% diameter stenosis without major complications) in 60 patients (98.4%). Mean diameter stenosis at baseline was 82 +/- 9.5% and post-angioplasty 13 +/- 10.6%. A mild intimal tear occurred in 6 patients (9.8%). A stent was implanted in 3 patients (4.9%) due to severe dissection. In hospital reocclusion occurred in one patient (1.6%). There were no deaths or emergency bypass surgery. A low profile PBC is safe and effective as an initial balloon in PTCA. It may reduce the number of balloons used and inflations per procedure.

An evaluation of some breeding management options in beef herds in the United Kingdom

The feasibility of replacing natural service in the suckler herd with artificial breeding (artificial insemination or embryo transfer), following synchronisation of oestrus in breeding animals, was investigated. In 1991 a herd of 143 spring-calving beef cows, matched for date and ease of calving, sex of calf, parity, body condition score and liveweight, were assigned to one of five controlled breeding programmes: natural service (group 1); single oestrus synchronisation using a norgestomet implant and fixed time insemination followed by natural service (group 2); double synchronisation with two consecutive norgestomet implants each with fixed-time insemination followed by natural service (group 3); synchronised as for group 2, but subjected to a movement stress two days after insemination (group 4); and cows synchronised by intravaginal progesterone/prostaglandin regimen with non-surgically transferred in vitro fertilised embryos followed by natural service (group 5). The percentage pregnancy rates to the first and second heats and overall were, respectively: group I, 55.5, 66.7 and 92.6; group 2, 44.4, 71.4 and 89.9; group 3, 52.0, 78.0 and 96.0; group 4, 55.0, 58.3 and 81.5, and group 5, 40.0, 68.2 and 85.7 per cent. In groups 2, 3, 4 and 5 the costs per pregnancy for artificial insemination or embryo transfer were 40.50 pounds, 56.62 pounds, 32.40 pounds and 149.98 pounds, respectively, and the calf weaning weights for groups 1, 2, 3, 4 and 5, adjusted for date of calving, were 250 kg, 255 kg, 252 kg, 261 kg and 259 kg, respectively.

Percutaneous transluminal coronary angioplasty in African-American patients (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Coronary Angioplasty Registry)

Although black patients have a higher prevalence of risk factors for coronary artery disease, the outcome of coronary angioplasty in black patients is not known. The purpose of this study was to determine if any racial differences existed in the clinical characteristics and outcome of patients enrolled in the 1985-1986 National Heart, Lung, and Blood Institute (NHLBI) Percutaneous Transluminal Coronary Angioplasty (PTCA) Registry. The clinical characteristics, in-hospital event rates, and 5-year follow-up results of all patients enrolled in the 1985-1986 NHLBI PTCA Registry were examined with respect to race. Of the patients enrolled in the registry, 1,939 (90.8%) were white and 76 (3.6%) were black. Among black patients there were more women (50% vs 24%, p < 0.001), and more patients who had hypertension (73% vs 45%, p < 0.001) and diabetes (23% vs 13%, p < 0.05). Black patients were more likely to have multivessel disease (72% vs 48%, p < 0.001). Clinical success rates were similar (76.3% for blacks and 79.3% for whites), but because black patients had more vessels with significant disease, complete revascularization was achieved in 26% of black patients compared with 44% of white patients (p < 0.001). After the PTCA procedure there was no significant difference in major complications (death, myocardial infarction, or emergent coronary artery bypass grafting) between the 2 groups. Five-year follow-up data revealed that there was no significant difference in mortality, myocardial infarction, coronary artery bypass grafting, or repeat PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Local delivery of a synthetic antithrombin with a hydrogel-coated angioplasty balloon catheter inhibits platelet-dependent thrombosis

OBJECTIVES

This study evaluated the efficacy of local administration of an antithrombin agent with a hydrogel-coated percutaneous transluminal coronary angioplasty balloon catheter.

BACKGROUND

Intravenous infusion of antithrombin compounds has been shown to inhibit platelet-dependent thrombosis. However, hemorrhage is a common side effect associated with the systemic administration of antithrombin compounds.

METHODS

The potent, irreversible thrombin inhibitor D-Phe-L-Pro-L-Arginyl chloromethyl ketone (PPACK) was used to inhibit thrombus formation in chronic porcine arteriovenous shunts. Platelet deposition was quantitated with gamma camera imaging of 111In-labeled platelets.

RESULTS

Intravenous administration of PPACK in swine, in doses sufficient to maximally inhibit thrombus formation, was associated with prolongation of bleeding parameters. The inhibition of thrombosis associated with intravenous PPACK was dose related. The amount of intravenous PPACK necessary for maximal inhibition of thrombus formation for a period of 45 min was 16.9 mg. In contrast, local delivery of PPACK with a hydrogel-coated angioplasty balloon deployed at the site of the thrombus inhibited platelet deposition for at least 45 min after the balloon was removed. Using 3H-labeled PPACK, the calculated amount of PPACK delivered was 33.5 micrograms. There was no change in bleeding time or activated partial thromboplastin time when swine received an intravenous bolus greater than the total amount of PPACK adsorbed onto the balloon (70 micrograms).

CONCLUSIONS

These results suggest that in this model, a hydrogel-coated coronary angioplasty balloon catheter can be used to deliver enough antithrombin agent to inhibit platelet-dependent thrombosis for at least 45 min at doses that are several orders of magnitude less than those required for systemic administration. In addition, local delivery can provide effective inhibition of thrombus formation without alteration of bleeding parameters.

Timing of ileocolonic resection for symptomatic Crohn's disease--the patient's view

Eighty patients were asked if they would have preferred their ileocolonic resection and anastomosis for Crohn's disease, to have been carried out sooner, later or at the same time as it was done. Seventy of the patients replied (88%). No patient would have preferred their operation to have been later, while 74% thought it should have been earlier. A preferred operation time was given for 69 resections, between 0 months--that is, at the same time--and 15 years earlier. The median preferred operation time was 12 months earlier (95% confidence intervals 18 months earlier to 7 months earlier). The remaining 18 patients were satisfied with the timing of their operation. Reasons given for earlier surgery in 58 resections included the severity of Crohn's symptoms preoperatively (97%), the ability to eat normally after resection (86%), feeling of well being after the resection (62%), and abolishing the need for drugs (43%). Patients preferring an earlier operation time were less likely to have had a previous resection (13/58) than patients in the 'same time' group (10/21, chi 2 = 4.746; p < 0.05).

Effects of cholinergic stimulation and aldosterone administration on salivary parotid secretion in the brushtail possum, Trichosurus vulpecula

Parotid salivation was stimulated by infusion of bethanechol chloride into anaesthetized brushtail possums to ascertain maximal flow rates, salivary composition and dietary adaptations of salivary function. Secretion rates for one gland ranged from 5.3 +/- 0.16 to 84.3 +/- 3.20 microliters/min (2.4 +/- 0.07 to 37.8 +/- 1.43 microliters/min per kg body weight). Salivary osmolality (160.8 +/- 15.39 to 248.2 +/- 8.70 mosmol/kg) and the concentrations of Na (63.1 +/- 10.93 to 124.1 +/- 5.52 mmol/l) and HCO3 (19.5 +/- 3.41 to 89.0 +/- 3.19 mmol/l) were positively correlated with flow rate. The concentrations of urea (7.8 +/- 0.64 to 4.6 +/- 0.33 mmol/l), PO4 (2.6 +/- 0.25 to 0.96 +/- 0.10 mmol/l), H+ (46.2 +/- 16.30 to 9.0 +/- 1.51 nequiv/l), K (21.4 +/- 3.73 to 13.7 +/- 2.33 mmol/l), Ca (3.7 +/- 0.53 to 2.2 +/- 0.27 mmol/l) and Mg (0.3 +/- 0.07 to 0.04 +/- 0.007 mmol/l) fell with increasing flow rate. The relations between flow rate and amylase activity (22.6 +/- 10.47 to 10.5 +/- 3.68 mu kat/l), protein concentration (2.7 +/- 0.61 to 1.3 +/- 0.28 g/l), and Cl concentration (62.1 +/- 6.88 to 50.6 +/- 6.37 mmol/l) were inconsistent between experiments. Salivary Na/K ratios were not decreased by infusion of aldosterone (2.2-22.2 nmol/h for 5 h), showing that the gland of Na-replete possums is unresponsive to short-term increases in mineralocorticoids. The low salivary amylase activity, less than that of kangaroos, presumably reflects the interaction of evolutionary history of the possum with its natural low-starch diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence and management of catheter-related sepsis in patients receiving home parenteral nutrition

Fifty patients, comprising 24 male and 26 female of median age 43 (range 15-67) years, received a total of 2620 patient-months of home parenteral nutrition (median 48 (range 2-130) months). There were 13 episodes of bacterial catheter sepsis (of which the catheter was successfully salvaged by an antibiotic-fibrinolytic 'lock' technique in four cases) and ten of exit-site sepsis (all managed by elective catheter replacement), representing an incidence of 1 septic complication per 113 patient-months of parenteral nutrition. This low incidence of catheter-related sepsis was achieved by strict adherence to established protocols of catheter management.

Surgical management of perineal and metastatic cutaneous Crohn's disease

Skin lesions are the commonest extraintestinal manifestation of Crohn's disease. Lesions that develop at sites remote from the gastrointestinal tract and have granulomas on histological examination are termed metastatic cutaneous Crohn's disease. Management is difficult as medical treatment is often ineffective. This report describes the use of surgical debridement of areas of perineal metastatic cutaneous Crohn's disease in five patients, all of whom had failed to improve after a variety of medical treatments. One patient had a poor result with continuing mild perineal discharge and four had a good outcome with complete resolution of symptoms and satisfactory cosmetic results.

The incidence and management of catheter occlusion in patients on home parenteral nutrition

For patients on Home parenteral nutrition (HPN), catheter-related problems are the major source of morbidity and occlusion of the central venous catheter is one of these. We have managed 17 episodes of catheter occlusion in 10 patients on HPN. The median time from insertion to occlusive episode was 23 months. 10 catheters (59%) were saved by the used of thrombolytics (one by thrombolytics and ethanol) and 7 were replaced. The recent incidence of catheter occlusion in this cohort was one episode per 150 patient-months of HPN (0.08 episodes per year). Patients with Crohns disease appear to be at greater risk of developing catheter occlusion (p = <0.05).

Recent changes in the management and outcome of acute closure after percutaneous transluminal coronary angioplasty

The major cause of morbidity and mortality associated with percutaneous transluminal coronary angioplasty (PTCA) is acute closure. This study compared the clinical outcome of 2 groups of patients who experienced acute closure during PTCA. One group was treated during a period when intracoronary stents, laser balloons and perfusion balloons were available for treatment of acute closure (group II). These results were compared with the clinical outcome a group of similar patients who were treated for acute closure during a period that immediately preceded the availability of these devices (group I). One hundred sixty-six patients had acute closure in group I, whereas 156 patients experienced acute closure in group II. Baseline clinical characteristics were similar for both groups. There was no difference in ejection fraction, number of vessels diseased, degree of stenosis or number of vessels attempted between the 2 groups. Patients in group II had more balloon inflations and longer balloon inflation times when compared with patients in group I. Of the 156 patients in group II, 47% were treated with either an intracoronary stent, laser balloon or perfusion balloon. Group II patients had fewer Q-wave myocardial infarctions (9.1 vs 20.3%, p = 0.005). In addition, peak creatine phosphokinase levels (826 +/- 1,515 vs 517 +/- 1,050, p < 0.01) and mean residual stenosis (40.7 +/- 33.2 vs 58.0 +/- 34.4%, p < 0.0001) were also lower in group II patients. There was also less coronary artery bypass grafting during the same admission (38.6 vs 29.5%, p = 0.02) in group II patients.(ABSTRACT TRUNCATED AT 250 WORDS)