Implementation of the robotic abdominal phase during robot-assisted minimally invasive esophagectomy (RAMIE): results from a high-volume center

BACKGROUND

Evidence on the added value of robotic-assistance in the abdominal phase during esophagectomy is scarce. In 2003, our center implemented the robotic thoracic phase for esophagectomy. In November 2018 the robot was also implemented in the abdominal phase. The aim of this study was to evaluate the implementation of the abdominal phase during robot-assisted minimally invasive esophagectomy (RAMIE).

METHODS

Consecutive patients who underwent full RAMIE with intrathoracic anastomosis for esophageal cancer were included. Patients were extracted from a prospectively maintained institutional database. A cumulative sum (CUSUM) analysis was performed for abdominal operation time and abdominal lymph node yield. Intraoperative, postoperative and oncological outcomes including collected lymph nodes per abdominal lymph node station were reported.

RESULTS

Between 2018 and 2021, 70 consecutive patients were included. The majority of the patients had an adenocarcinoma (n = 55, 77%) and underwent neoadjuvant chemo(radio)therapy (n = 65, 95%). The median operative time for the abdominal phase was 180 min (range 110-233). The CUSUM analysis for abdominal operation time showed a plateau at case 22. There were no intraoperative complications or conversions during the abdominal phase. The most common postoperative complications were pneumonia (n = 18, 26%) and anastomotic leakage (n = 14, 20%). Radical resection margins were achieved in 69 (99%) patients. The median total lymph node yield was 42 (range 23-83) and the median abdominal lymph node yield was 16 (range 2-43). The CUSUM analysis for abdominal lymph node yield showed a plateau at case 21. Most abdominal lymph nodes were collected from the left gastric artery (median 4, range 0-20).

CONCLUSIONS

This study shows that a robotic abdominal phase was safely implemented for RAMIE without compromising intraoperative, postoperative and oncological outcomes. The learning curve is estimated to be 22 cases in a high-volume center with experienced upper GI robotic surgeons.

Impact of the COVID-19 pandemic on surgical care in the Netherlands

BACKGROUND

The COVID-19 pandemic caused disruption of regular healthcare leading to reduced hospital attendances, repurposing of surgical facilities, and cancellation of cancer screening programmes. This study aimed to determine the impact of COVID-19 on surgical care in the Netherlands.

METHODS

A nationwide study was conducted in collaboration with the Dutch Institute for Clinical Auditing. Eight surgical audits were expanded with items regarding alterations in scheduling and treatment plans. Data on procedures performed in 2020 were compared with those from a historical cohort (2018-2019). Endpoints included total numbers of procedures performed and altered treatment plans. Secondary endpoints included complication, readmission, and mortality rates.

RESULTS

Some 12 154 procedures were performed in participating hospitals in 2020, representing a decrease of 13.6 per cent compared with 2018-2019. The largest reduction (29.2 per cent) was for non-cancer procedures during the first COVID-19 wave. Surgical treatment was postponed for 9.6 per cent of patients. Alterations in surgical treatment plans were observed in 1.7 per cent. Time from diagnosis to surgery decreased (to 28 days in 2020, from 34 days in 2019 and 36 days in 2018; P < 0.001). For cancer-related procedures, duration of hospital stay decreased (5 versus 6 days; P < 0.001). Audit-specific complications, readmission, and mortality rates were unchanged, but ICU admissions decreased (16.5 versus 16.8 per cent; P < 0.001).

CONCLUSION

The reduction in the number of surgical operations was greatest for those without cancer. Where surgery was undertaken, it appeared to be delivered safely, with similar complication and mortality rates, fewer admissions to ICU, and a shorter hospital stay.

Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

Tranexamic acid therapy for postoperative bleeding after bariatric surgery

BACKGROUND

Tranexamic acid reduces blood loss associated with various surgical procedures. Postoperative bleeding caused by dissection or bleeding of the enteric staple lines is a well-known complication following bariatric surgery. Reoperation in order to restore hemostasis is frequently necessary (up to 2.5% in literature). The effect of conservative therapy using tranexamic acid for postoperative hemorrhage after bariatric surgery is still very much a novel technique. The aim is to present our results (reoperation rate and thrombo-embolic complication rate) of tranexamic acid therapy for postoperative bleeding after bariatric surgery in comparison to those in existing literature.

METHODS

We retrospectively reviewed 1388 patients who underwent bariatric surgery (laparoscopic gastric bypass or laparoscopic gastric sleeve). Use of tranexamic acid, reoperation rate, transfusion rate and rate of thrombo-embolic complications were reviewed.

RESULTS

Forty-five of 1388 (3.2%) total patients experienced significant hemorrhage after bariatric surgery. Tranexamic acid was administered in 44 of these patients. A failure of the treatment with tranexamic acid was observed in four patients. The incidence of reoperation was 0.4% for the entire population. No thrombo-embolic complications were registered for patients receiving tranexamic acid.

CONCLUSION

These findings suggest that the administration of tranexamic acid appears to be safe in reducing the reoperation rate for bleeding after bariatric surgery.

Oesophagectomy: The expanding role of minimally invasive surgery in oesophageal cancer

Historically, open oesophagectomy was the gold standard for oesophageal cancer surgery. This was associated with a relatively higher morbidity. In the last two decades, we have seen significant improvements in short and long term outcomes due to centralisation of oesophagectomy, multidisciplinary approach, enhanced recovery after surgery programmes, neoadjuvant treatments and advances in minimally invasive oesophagectomy (MIO) techniques. MIO has significantly reduced postoperative morbidity and improved functional recovery, while maintaining comparable long-term oncological outcomes. MIO is technically demanding, and requires a long learning curve. However, it has been proven to be safe and successful in expert centres. This is a review on the current role of MIO in the management of oesophageal cancer.

[A man with abdominal pain, diarrhoea and rectal bleeding]

A 49-year-old man came to the emergency room with abdominal pain, vomiting, diarrhoea and rectal bleeding. Both colonoscopy and CT of the abdomen showed cecocolic intussusception caused by an appendiceal mucocele. An ileocecal resection was performed via a laparoscopic approach and microscopy of the tissue showed a low-grade mucinous neoplasm.

A qualitative interview study on the positive well-being of medical school faculty in their teaching role: job demands, job resources and role interaction

BACKGROUND

Attention for the well-being of medical school faculty is not only important for the prevention of attrition and burnout, but may also boost performance in their tasks in medical education. Positive well-being can be conceptualized as work engagement and this is associated with increased performance. In this study we explore how demands and resources from different tasks affect work engagement specifically for education.

METHODS

Between June and September 2013, we conducted a multisite semi-structured interview study with a diverse group of medical school faculty and used an open-coding strategy within the Work Engagement Model on the transcribed interviews.

RESULTS

We interviewed 16 faculty members whose teaching experience ranged from 7 to 38 years and whose professional tasks ranged from being solely an educator to being a physician, researcher, educator and administrator simultaneously. All participants were clear on the perceived demands and resources, although similar aspects of the work environment could be perceived oppositely between participants. Overarching themes were perceptions related to the organization or department, often described as a general and long-term effect and perceptions directly related to a task, often described as a direct and short-term effect on well-being. Furthermore, the demands and resources as resultant of fulfilling multiple tasks were described clearly by participants.

CONCLUSIONS

The ambiguous nature of the work environment in terms of demands and resources requires an individualized approach to supporting work engagement. Furthermore, faculty members perceive many resources from fulfilling multiple tasks in relation to their tasks in education. Faculty developers and administrators alike could use these findings to apply the concept of work engagement to their daily support of faculty in medical education.

[Risk assessment with intellectual disabled forensic psychiatric patients: how useful are risk assessment instruments?]

BACKGROUND

Instruments for assessing the risk of violent behaviour have proved their worth in the field of forensic psychiatry. However, it is not certain whether such instruments provide an accurate assessment of recidivism when used with psychiatric patients who have an intellectual disability.

AIM

To find out whether these instruments - or which of these instruments - can provide a reliable assessment of the risk of violent sexual recidivism if used with forensic psychiatric patients who have an intellectual disability. method We searched PubMed, PsycINFO and Google Scholar for studies in English or Dutch, published between 1980 and 2010, concerning the reliability of instruments for assessing the risk of recidivism in forensic psychiatric patients with an intellectual disability.

RESULTS

The studies show that several of the risk assessment instruments currently in use provide reliable predictions concerning patients with an intellectual disability.

CONCLUSIONS

The HCR-20 and HKT-30 are recommended for assessing the risk of violent recidivism in patients with an intellectual disability. The Static-99 is the preferred instrument for assessing the risk of sexual recidivism. Further research is needed for assessing to what extent SVR-20, ARMIDILO, DROS, and PCL-R are applicable to forensic psychiatric patients in the Netherlands who have an intellectual disability.

Minimum protein requirements in liver cirrhosis determined by nitrogen balance measurements at three levels of protein intake

Nitrogen balance at three levels of protein intake was measured in eight patients with cirrhosis of the liver; moreover, at each level of protein intake, the effects on nitrogen balance of branched-chain amino-acid enriched protein and natural protein were compared. From these nitrogen balance data, minimum protein requirements were calculated by linear regression analysis. The patients were in a negative nitrogen balance on a 40 g protein diet (-0.75 +/- 0.15 gN.), and in positive nitrogen balance on 60 g (+1.23 +/- 0.22 gN.) or 80 g of protein per day (+2.77 +/- 0.20 g N.). Their mean minimum protein requirement (48 +/- 5 g of protein/day or 0.75 g/kg/day) is higher than expected in healthy people; the safe level of protein intake (mean + 2 sd) is 58 g per day or 1.2 g/kg/day. Nitrogen balances and protein requirements were not different on branched-chain amino-acid enriched diets. The physical condition of the patients improved when they came into positive nitrogen balance; the higher rates of protein intake were well tolerated without onset of encephalopathy. We conclude that protein requirements are elevated in cirrhosis of the liver; diets supplying less than 60 g of protein per day should not be prescribed in long term treatment of cirrhotic patients.

Albumin and whole-body protein synthesis respond differently to intraperitoneal and oral amino acids

Patients with peritoneal dialysis are at risk for malnutrition and hypoalbuminemia, which are indicators of poor outcome. Recently, it was shown that dialysis solutions containing amino acids (AAs) and glucose improve protein anabolism in peritoneal dialysis patients. We determined if the same solutions could increase the fractional synthesis rate of albumin along with whole-body protein synthesis. Changes in the fractional albumin synthetic rate reflect acute change in hepatic albumin synthesis. A random-order cross-over study compared the effects of Nutrineal (AA source) plus Physioneal (glucose) dialysate with Physioneal alone dialysate. Eight patients in the overnight fasting state were compared to 12 patients in the daytime-fed state. Fractional albumin synthetic rate and whole-body protein synthesis were determined simultaneously using a primed-continuous infusion of L-[1-(13)C]-leucine. Fractional albumin synthesis on AAs plus glucose dialysis did not differ significantly from that on glucose alone in the fasting or the fed state. Protein intake by itself (fed versus fasting) failed to induce a significant increase in the fractional synthetic rate of albumin. Conversely, the oral protein brought about a significant stimulation of whole-body protein synthesis. Our findings show that the supply of AAs has different effects on whole-body protein synthesis and the fractional synthetic rate of albumin.

Long-term outcome of lung transplantation is predicted by the number of HLA-DR mismatches

BACKGROUND

The importance of HLA mismatch in determining long-term outcome in lung transplantation remains largely uncertain.

METHODS

A retrospective analysis of 102 consecutive primary lung transplants was performed to identify risk factors for poor long-term outcome after lung transplantation defined as graft survival and bronchiolitis obliterans syndrome (BOS) stage I and II. Variables included were patient characteristics (age, sex, prior diagnosis), the number of HLA mismatches between donor and recipient, cold ischemic time, cytomegalovirus serologic concordance, number of acute rejections, and time to first rejection. Variables carrying significance in a univariate analysis were subjected to a proportional hazard regression analysis.

RESULTS

In the multivariate analysis, an increased number of acute rejections correlated positively with decreased graft survival (risk ratio [RR] = 1.25; 95% confidence interval [CI], 1.05-1.5; P = 0.011), development of BOS stage I (RR = 1.36/episode; 95% CI, 1.16-1.58;P < 0.001), and BOS stage II (RR = 1.42/episode; 95% CI, 1.2-1.67; P < 0.001). An increased time to rejection correlated positively with reduced graft survival (RR = 1.03/day; 95% CI, 1.01-1.06; P = 0.02), and BOS stage I and II (both RR = 1.04/day; 95% CI, 1.01-1.07; P < 0.005). Compared with 2 HLA-DR mismatches, 0 or 1 mismatch was associated with improved graft survival (RR = 0.43; 95% CI, 0.19-0.98; P = 0.045) and protected against development of BOS stage I (RR = 0.47; 95% CI, 0.23-0.98; P = 0.044) and BOS stage II (RR = 0.35; 95% CI, 0.15-0.83; P = 0.017).

CONCLUSIONS

HLA-DR mismatching appears to be a risk factor for the development of BOS and graft loss. Improved outcome after lung transplantation might be achieved with prospective matching for HLA-DR. Alternatively, the amount and type of immunosuppressive drugs may be guided by the degree of HLA-DR (mis)matching.

Eosinophilic granulocytes and interleukin-6 level in bronchoalveolar lavage fluid are associated with the development of obliterative bronchiolitis after lung transplantation

In a prospective cohort study, we assessed whether changes in total cell counts and differentiation and interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein-1 (MCP-1) concentrations in bronchoalveolar lavage fluid (BALF) are associated with a higher risk to develop obliterative bronchiolitis (OB). We investigated 60 lung transplant patients (follow-up of 2 to 8 yr) with either histologic evidence of OB within 1 yr after lung transplantation (n = 19) or no pathology, good outcome (GO) for at least 24 mo and well-preserved lung function, i.e., FEV > or = 80% of baseline (n = 41). Median time between lung transplantation and the first BAL was 42 d for the GO group and 41 d for the OB group (p > 0.05). In the bronchial fraction, median total cell counts (0.06 x 10(3)/ml versus 0.04 x 10(3)/ml), lymphocyte (9 x 10(3)/ml versus 2 x 10(3)/ml), and eosinophilic granulocyte counts (1 x 10(3)/ml versus 0) were significantly higher in the OB group than in the GO group (p < 0.05). In the alveolar fraction, this was the case for the median value of neutrophilic granulocyte counts (19 x 10(3)/ml versus 4 x 10(3)/ml), respectively. Median values of IL-6 and IL-8 concentrations in both bronchial (IL-6: 23 versus 6 pg/ml, IL-8: 744 versus 102 pg/ml) and alveolar fractions (IL-6: 13 versus 3 pg/ml, IL-8: 110 versus 30 pg/ml) of the BALF were significantly higher in the OB group than in the GO group. By means of logistic regression, we showed that higher total cell, neutrophilic granulocyte, and lymphocyte counts, the presence of eosinophilic granulocytes, and higher concentrations of IL-6 and IL-8 were significantly associated with an increased risk to develop OB. We conclude that monitoring cell counts, neutrophilic and eosinophilic granulocytes, IL-6, and IL-8 in BALF within 2 mo after lung transplantation in addition to the transbronchial lung biopsy (TBB) pathology will contribute to a better identification and management of the group of patients at risk for developing OB within a year.

Bronchiolitis obliterans syndrome and additional costs of lung transplantation

STUDY OBJECTIVES

The influence of bronchiolitis obliterans syndrome (BOS) on costs after lung transplantation was investigated by comparing the costs of patients with and without this condition.

DESIGN

Follow-up costs were prospectively investigated in a medical technology assessment of the Dutch Lung Transplant Program, in relation to the development of the BOS. First, average follow-up costs per week per patient were compared between patients who did or did not develop BOS. Second, in the BOS group, these costs were compared before and after the onset of BOS.

SETTING

Dutch Lung Transplant Program, University Hospital of Groningen.

RESULTS

Data on 53 patients (37 patients without BOS and 16 with BOS) who underwent transplantation between November 1990 and April 1995 were available. The average follow-up time of these 53 patients was 1.5 years. The follow-up costs amounted to an average (in Dutch guilders [Dfl]) of 1,774/wk for non-BOS patients, compared to 3,072/wk for BOS patients (+ 73%; p = 0.002; one Dfl = 50 cents US currency). This difference in costs was largely accounted for by an increase in used health-care resources, in particular hospitalization and medication. For the BOS patients, the average costs per week before and after the onset of BOS were 1,941 Dfl and 2,422 Dfl, respectively.

CONCLUSION

BOS is associated with substantial extra costs. These findings reemphasize the need to focus efforts on prevention of BOS to enhance the cost-effectiveness of lung transplantation.

Lipolysis and lipid oxidation in weight-losing cancer patients and healthy subjects

Increased lipolysis has been suggested as one of the possible mechanisms underlying cancer cachexia. The study aim was to assess whether lipolysis is increased in weight-losing cancer patients, considering their differences in food intake and body composition. Sixteen healthy subjects and 18 cancer patients with different tumor types and a weight loss of at least 5% in the previous 6 months were included in the study. Food intake was recorded for 4 days. After an overnight fast, [1,1,2,3,3-2H5]glycerol was infused to determine the rate of appearance (Ra) of glycerol as a measure of whole-body lipolysis, and [1-13C]palmitic acid was infused to determine the Ra of palmitate as a measure of adipocyte fatty acid release. Palmitate oxidation was determined by measuring 13CO2 enrichment in breath samples, and body composition was measured by bioelectrical impedance analysis. After adjustment for energy intake, whole-body lipolysis was significantly higher in cancer patients versus healthy subjects (6.46 +/- 0.63 and 4.67 +/- 0.46 micromol/kg +/- min, respectively, P < .05). The difference in adipocyte fatty acid release did not reach statistical significance. The rate of palmitate oxidation was also significantly higher in patients than in healthy subjects (1.15 +/- 0.10 and 0.93 +/- 0.07 )micromol/kg x min, respectively, P < .05). No differences in body composition were observed between groups. In conclusion, whole-body lipolysis (as measured by the Ra of glycerol) and palmitate oxidation were elevated in weight-losing cancer patients, but fatty acid release was not significantly different.

Cyclosporine, FK506, mycophenolate mofetil, and prednisolone differentially modulate cytokine gene expression in human airway-derived epithelial cells

BACKGROUND

The immunosuppressive effects of cyclosporine (CsA), tacrolimus (FK506), mycophenolate mofetil (MMF), and prednisolone in cells from the immunological compartment are well documented. In contrast, limited information is available with respect to the effects of these immunosuppressive drugs on airway-epithelial cells, although these cells may contribute to the development of obliterative bronchiolitis (OB) through the production of interleukin (IL)-6 and IL-8.

METHODS

We studied the production of IL-6 and IL-8 proteins by airway-derived epithelial cell lines and primary epithelial cell cultures obtained from lung brushings. Transcriptional mechanisms were detected by transient transfections.

RESULTS

We demonstrate that CsA dose dependently induces the production of the proinflammatory cytokines IL-6 and IL-8 in both cell lines and primary epithelial cells. FK506 and MMF were also able to upregulate IL-8, although the effect was less dramatic than observed for CsA. Low concentrations of prednisolone (0.01 and 0.001 microg/ml) enhanced IL-6 and IL-8 secretion, whereas concentrations > or =0.01 microg/ml significantly diminished IL-6 secretion. Furthermore, we showed that CsA and prednisolone mediate their effects at the transcriptional level.

CONCLUSIONS

The data provide evidence that relevant concentrations of CsA and MMF in vivo may enhance the inflammatory processes in the lower airways of patients after lung transplantation.

Pharmacokinetics of intravenous ATP in cancer patients

OBJECTIVE

To characterise the pharmacokinetics of adenosine 5'-triphosphate (ATP) in patients with lung cancer after i.v. administration of different ATP dosages.

METHODS

Twenty-eight patients received a total of 176 i.v. ATP courses of 30 h. Fifty-two infusions were given as low-dose infusions of 25-40 microg kg(-1) min(-1), 47 as middle-dose infusions of 45-60 microg kg(-1) min(-1) and 77 as high-dose infusions of 65-75 microg kg(-1) min(-1) ATP. Kinetic data of ATP concentrations in erythrocytes were available from 124 ATP courses. Results are expressed as mean +/- SEM.

RESULTS

Most ATP courses in cancer patients were without side effects (64%), and side effects occurring in the remaining courses were mild and transient, resolving within minutes after decreasing the infusion rate. Baseline ATP concentration in erythrocytes was 1,554 +/- 51 micromol l(-1). ATP plateau levels at 24 h were significantly increased by 53 +/- 3, 56 +/- 3 and 69 +/- 2% after low-dose, middle-dose and high-dose ATP infusions, respectively. At the same time, significant increases in plasma uric acid concentrations were observed: 0.06 +/- 0.01, 0.11 +/- 0.01 and 0.16 +/- 0.01 mmol l(-1), respectively. The mean half-time for disappearance of ATP from erythrocytes, measured in five patients, was 5.9 +/- 0.5 h.

CONCLUSIONS

During constant i.v. infusion of ATP in lung cancer patients, ATP is taken up by erythrocytes and reaches dose-dependent plateau levels 50-70% above basal concentrations at approximately 24 h.

Altered hepatic gluconeogenesis during L-alanine infusion in weight-losing lung cancer patients as observed by phosphorus magnetic resonance spectroscopy and turnover measurements

Profound alterations in host metabolism in lung cancer patients with weight loss have been reported, including elevated phosphomonoesters (PMEs) as detected by 31P magnetic resonance spectroscopy (MRS). In healthy subjects, infusion of L-alanine induced significant increases in hepatic PMEs and phosphodiesters (PDEs) due to rising concentrations of 3-phosphoglycerate and phosphoenolpyruvate, respectively. The aim of the present study was to monitor these changes in the tumor-free liver of lung cancer patients during L-alanine infusion by means of simultaneous 31P MRS and turnover measurements. Twenty-one lung cancer patients without liver metastases with (CaWL) or without weight loss (CaWS), and 12 healthy control subjects were studied during an i.v. L-alanine challenge of 1.4-2.8 mmol/kg followed by 2.8 mmol/kg/h for 90 min. Plasma L-alanine concentrations increased during alanine infusion, from 0.35-0.37 mM at baseline to 5.37 +/- 0.14 mM in the CaWL patients, 6.67 +/- 0.51 mM in the CaWS patients, and 8.47 +/- 0.88 mM in the controls (difference from baseline and between groups during alanine infusion, all P < 0.001). Glucose turnover and liver PME levels at baseline were significantly elevated in the CaWL patients. Alanine infusion increased whole-body glucose turnover by 8 +/- 3% in the CaWS patients (P = 0.03), whereas no significant change occurred in the CaWL and controls. PME levels increased by 50 +/- 16% in controls (area under the curve, P < 0.01) and by 87 +/- 31% in the CaWS patients (P < 0.05) after 45-90 min. In contrast, no significant changes in PME levels were observed in the CaWL patients. Plasma insulin concentrations increased during L-alanine infusion in all groups to levels that were lower in the CaWL patients than in the CaWS patients and controls (P < 0.05). In lung cancer patients, but not in controls, changes in PME and PDE levels during alanine infusion were inversely correlated with their respective baseline levels (r = -0.82 and -0.86, respectively; P < 0.001). In addition, changes in PMEs during alanine infusion in lung cancer patients were inversely correlated with the degree of weight loss (r = -0.54; P < 0.05). This study demonstrates the presence of major alterations in the pathway of hepatic gluconeogenesis in weight-losing lung cancer patients, as shown by elevated glucose flux before and during L-alanine infusion, and by the increased PME and PDE levels, which reflect accumulation of gluconeogenic intermediates in these patients. Weight-stable lung cancer patients show accelerated increases in PME and PDE levels during L-alanine infusion, suggesting enhanced induction of the gluconeogenic pathway. Our results suggest altered gluconeogenic enzyme activities and elevated alanine uptake within the livers of weight-losing/weight-stable lung cancer patients.

Incorporation and washout of orally administered n-3 fatty acid ethyl esters in different plasma lipid fractions

The aim of the present study was to quantify the incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids after oral administration of n-3 fatty acid ethyl esters, since little is known about the rate and pattern of incorporation into plasma lipid fractions. In addition, we aimed to obtain preliminary information regarding EPA half-life, which is needed to establish an optimal dosing schedule. Five healthy volunteers ingested two 8.5 g doses of n-3 fatty acid ethyl esters daily for 7 d, supplying 6.0 g EPA/d and 5.3 g DHA/d. The fatty acid compositions of plasma phospholipids (PL), cholesteryl esters (CE) and triacylglycerols (TAG) were determined during supplementation and during a washout period of 7 d. Half-lives of EPA and DHA were calculated. The proportion of EPA in PL showed a 15-fold increase after 7 d (P < 0.001), while DHA showed a smaller increase (P < 0.01). In CE, EPA also increased (P < 0.05), while DHA did not increase at all. Remarkably, incorporation of DHA into TAG was even higher than that of EPA. Half-life of EPA in PL ranged from 1.63 to 2.31 d (mean 1.97 (SE 0.15) d), whereas mean half-life of EPA in CE was 3.27 (SE 0.56) d. In three subjects, washout of EPA and DHA from TAG seemed to follow a bi-exponential pattern, with a short half-life (< 1 d) in the initial phase and a half-life of several days in the second phase. In conclusion, EPA ethyl esters are rapidly incorporated into plasma lipids, especially into PL. The relatively long half-life of EPA in plasma would permit a dosing schedule with intervals of > or = 12 h in supplementation studies.

[Survival and impact of bronchiolitis obliterans syndrome after lung transplantation at the Academic Hospital Groningen, 1990/'98]

OBJECTIVE

To describe the results of the lung transplantation programme in Groningen in relation to the bronchiolitis obliterans syndrome (BOS), in the first 118 consecutive patients.

DESIGN

Retrospective.

METHOD

Data were collected on the 118 patients subjected to lung transplantation in November 1990 to June 1998 in the University Hospital Groningen, the Netherlands, regarding the prevalence of chronic transplant dysfunction (BOS) and survival.

RESULTS

117 lung transplantations (95 bilateral lung transplantations including 2 retransplants, and 22 single lung transplantations) and 1 heart-lung transplantation had been performed. The patients were 70 males and 48 females with a mean age of 42 years (range: 9-64). The mean (SD) survival at 1, 2, 3 and 5 years post transplantation was 83% (3), 70% (4), 66% (5) and 61% (5) respectively. The median survival amounted to 2447 days. The mean (SD) prevalence of BOS at respectively 1, 2, 3 and 5 years post transplantation was 32% (5), 36% (5), 44% (5) en 54% (6). After a diagnosis of BOS stage I the median survival was 649 days.

CONCLUSION

The survival of the lung transplant programme of the University Hospital Groningen is considered to compare favourably with other centres. The prevalence of BOS is considerable, and comparable with the prevalence of BOS reported by other programmes. BOS is associated with a decreased life expectancy.

Adenosine triphosphate: established and potential clinical applications

Adenosine 5'-triphosphate (ATP) is a purine nucleotide found in every cell of the human body. In addition to its well established role in cellular metabolism, extracellular ATP and its breakdown product adenosine, exert pronounced effects in a variety of biological processes including neurotransmission, muscle contraction, cardiac function, platelet function, vasodilatation and liver glycogen metabolism. These effects are mediated by both P1 and P2 receptors. A cascade of ectonucleotidases plays a role in the effective regulation of these processes and may also have a protective function by keeping extracellular ATP and adenosine levels within physiological limits. In recent years several clinical applications of ATP and adenosine have been reported. In anaesthesia, low dose adenosine reduced neuropathic pain, hyperalgesia and ischaemic pain to a similar degree as morphine or ketamine. Postoperative opioid use was reduced. During surgery, ATP and adenosine have been used to induce hypotension. In patients with haemorrhagic shock, increased survival was observed after ATP treatment. In cardiology, ATP has been shown to be a well tolerated and effective pulmonary vasodilator in patients with pulmonary hypertension. Bolus injections of ATP and adenosine are useful in the diagnosis and treatment of paroxysmal supraventricular tachycardias. Adenosine also allowed highly accurate diagnosis of coronary artery disease. In pulmonology, nucleotides in combination with a sodium channel blocker improved mucociliary clearance from the airways to near normal in patients with cystic fibrosis. In oncology, there are indications that ATP may inhibit weight loss and tumour growth in patients with advanced lung cancer. There are also indications of potentiating effects of cytostatics and protective effects against radiation tissue damage. Further controlled clinical trials are warranted to determine the full beneficial potential of ATP, adenosine and uridine 5'-triphosphate.

Human liver glycogen metabolism assessed with a 13C-enriched diet and a 13CO2 breath test

BACKGROUND

Adequate liver glycogen stores to maintain hepatic glucose output by glycogenolysis in the post-absorptive state are essential to prevent protein loss through gluconeogenesis. There are no simple techniques to monitor liver glycogen use.

METHODS

In this study, we labelled liver glycogen with naturally 13C-enriched carbohydrate and measured the pattern of 13CO2 excretion and the post-prandial time during which oxidation of 13C-labelled liver glycogen was demonstrable by 13CO2 enrichment in breath. Two experiments were performed in 24 healthy volunteers.

RESULTS

In the first experiment we observed that breath 13CO2 enrichment returned to baseline values at 20.3 (SD 2.3, n = 12) hours post-prandially, indicating exhaustion of the 13C-labelled liver glycogen at that time. In a second experiment, breath 13CO2 enrichment in the early hours of the post-prandial phase was studied. After a steep decline, which started 2-4 h after the last meal, the 13CO2 enrichment reached a plateau phase 6 h post-prandially. This plateau phase lasted for about 6-8 h, suggesting steady-state glycogenolysis during this period. The plateau phase was followed by a further decline in 13CO2 excretion, suggesting a gradually diminishing contribution of 13C-labelled liver glycogen to substrate oxidation.

CONCLUSION

It is possible to label liver glycogen with a diet of naturally 13C-enriched carbohydrate. The oxidation of the labelled liver glycogen can be monitored by measuring 13C-enrichment in breath CO2.

13C breath test in gastroenterological practice

Breath tests (BTs) are used in gastroenterological practice to study (patho)physiological and metabolic processes in an indirect way. In these tests the appearance in breath of a metabolite of a specific test substance is studied. The assumption underlying each BT is that one step-the process of interest-in the absorption and metabolism of the tracer is rate-limiting. Both hydrogen gas excretion and carbon dioxide appearance in breath can be studied. When a carbon-labelled test substance is used. the stable isotope 13C is preferred to the radioactive isotope 14C. Measurements of 13C in expired air are performed by mass spectrometry. Because of the indirect nature of BTs, involving a sequence of reactions and metabolic pools, they usually supply semiquantitative data. The tests are nevertheless useful because they often replace invasive techniques with a simple procedure that is safe because there is no radioactivity involved. BTs have been used to measure gastric emptying, the presence of Helicobacter pylori in the stomach, small-bowel bacterial overgrowth, exocrine pancreatic function as well as liver metabolic capacity; other potential applications of BTs are being studied.

Evaluation studies of the 13C-mixed triglyceride breath test in healthy controls and adult cystic fibrosis patients with exocrine pancreatic insufficiency

The 13C-mixed triglyceride (13C-MTG) breath test (BT) is a safe and noninvasive method to measure exocrine pancreatic function. We examined the reproducibility of the 13C-MTG BT in a group of 17 healthy controls and 8 adult patients with cystic fibrosis (CF). In controls no statistically significant difference in percentage dose recovered (PDR) was found between the first and the second result of repeated tests: the mean values were 35.5 +/- 5.5 vs. 32.3 +/- 7.4 PDR (n = 17). Also in the group of CF patients (n = 8) no significant difference between duplicate tests was found: mean values 17.5 +/- 7.5 and 17.5 +/- 7.8 PDR, respectively. The coefficient of repeatability is 8 PDR for the controls and CF patients together. Two factors might influence the outcome of the test. First, individually measured CO2 excretion instead of the usually assumed 9 mmol/h/kg CO2 production might alter the result of the 13CO2-MTG BT. Therefore CO2 production was measured by indirect calorimetry in 12 healthy controls and 13 CF patients. Measured CO2 excretion was not significantly different between healthy controls and CF patients. Secondly, exercise might influence BT results due to its separate effects on both CO2 production and excretion. The influence of physical exercise at a level of 25 or 50 W was studied on a bicycle ergometer in 4 healthy controls during the last 5 min of each 30-min sampling period. Exercise gave lower test results, on average 85% of the PDR value at rest. Incidently, it was observed in 1 patient that use of 13C-enriched food during the day preceding the test caused inappropriately low test results in the 13C-MTG BT. The 13C-MTG BT is a test with a fair but less than desirable reproducibility. Test conditions should be standardized to eliminate confounding influences. Exercise should be limited or strictly defined. Diet on the day preceding the test should not contain naturally 13C-enriched food. There is no need to measure individual CO2 production.

Dietary level and source of neutral detergent fiber and ileal endogenous nitrogen flow in pigs

Two experiments were conducted to study the effect of dietary level and source of neutral detergent fiber (NDF) on ileal dry matter flow and on total and endogenous N flow at the terminal ileum. Twenty-two crossbred 6-wk-old castrated male pigs with an average BW of 9 kg were used. The pigs were fitted with a post-valvular T-cecal cannula and two indwelling blood catheters. During the experimental period of 10 d, the pigs were 11 wk of age with an average BW of 14 kg. They were fed 2.6 times their maintenance requirement for energy of a corn starch-based, semisynthetic diet. The diets contained 178 g of soy isolate/kg as the only source of nitrogen (N). In diets of Exp. 1, purified NDF was included at 0 and 200 g/kg of feed at the expense of glucose. The diets of Exp. 2 contained one of the three different NDF sources (purified NDF, wheat bran, or sunflower hulls) at a level of 144 g of NDF/kg of DM. The purified NDF (pNDF) was isolated from the same batch as the wheat bran (WB) used in Exp. 2. The endogenous N flow at the terminal ileum of these pigs was determined with the 15N-isotope dilution method. The inclusion of NDF in the experimental diets increased (P < .05) the daily DM flow at the terminal ileum. Dry matter flow was increased .697 g for every g/kg increase in NDF in the diet. The different sources of dietary NDF gave similar (P > .05) ileal DM flows.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of hulls of faba beans (Vicia faba L.) with a low or high content of condensed tannins on the apparent ileal and fecal digestibility of nutrients and the excretion of endogenous protein in ileal digesta and feces of pigs

In three experiments (Exp. 1, 2, and 3) with young pigs (BW 10 to 26 kg), the effects of dietary inclusion of hulls of faba beans (Vicia faba L.) (200 g/kg) with a low (< .1% catechin equivalents; LT) or high tannin content (3.3% catechin equivalents; HT) on the apparent ileal (Exp. 1 and 2) and fecal (Exp. 3) digestibility of nutrients were determined. In addition, the true digestibility of protein of the diets and the excretion of endogenous protein (N x 6.25) in ileal digesta and feces of pigs were measured, using the 15N isotope dilution technique (Exp. 3). Diets contained either casein and faba bean cotyledons as highly soluble (HS) protein sources (Exp. 1 to 3) or potato protein, soy concentrate, sunflower meal, meat meal, and fish meal as protein sources with a low solubility (LS) (Exp. 1). Control diets contained cellulose as a fiber source (64 to 73 g/kg). Inclusion of either type of hulls decreased the apparent ileal digestibility for DM, organic matter (OM), and nonprotein organic matter (NPOM) (P < .05). Inclusion of LT hulls instead of cellulose only reduced the apparent ileal digestibility of crude protein (N x 6.25; CP) in Exp. 3 (P < .05). Inclusion of HT instead of LT hulls reduced the apparent ileal digestibility of CP (by 7 to 10 units) and amino acids (by 4 to 29 units) (P < .05). The LT hulls decreased apparent and true ileal digestibility of CP from 88 to 83 and from 97 to 94, respectively (P < .05). Inclusion of HT instead of LT hulls decreased apparent and true ileal CP digestibility from 83 to 74 and 94 to 90 (P < .05) and increased the excretion of endogenous CP from 22 to 32 and from 13 to 23 g/kg of DM intake at the ileal and fecal level, respectively (P < .05). It is concluded that condensed tannins in faba beans interact with both dietary and endogenous proteins in the digestive tract of pigs. This reduces the true digestibility of dietary protein and increases the excretion of endogenously secreted proteins. Tannins from faba beans show some preference to interact with proteins with a high content of proline and histidine.

Effect of dietary fish oil on blood levels of free fatty acids, ketone bodies and triacylglycerol in humans

Although the reduction of serum triacylglycerol concentrations by dietary fish oil is a well-known effect, the exact mechanism of this effect has not been previously studied in human subjects. Therefore, the aim of this study was (i) to examine the effect of short-term fish oil supplementation on blood concentrations of ketone bodies, free fatty acids and triacylglycerol in healthy humans and (ii) to verify whether the observed relationships between these variables would be consistent with reduced lipolysis and/or enhanced hepatic fatty acid oxidation after fish oil supplementation. Twenty subjects (21-23 years, normal liver function tests) were randomly divided into two groups to supplement their usual diet with either 30 g/d of fish oil (n = 11) or olive oil (n = 9). Venous blood samples were drawn after an overnight fast, before and after 1, 3 and 7 d of fish oil/olive oil supplementation. Blood concentrations of triacylglycerol and free fatty acids decreased consistently after fish oil supplementation; the reduction was already significant after one day of fish oil (P < 0.001 for triacylglycerol and P = 0.01 for free fatty acids). In contrast, neither of these blood values changed after olive oil supplementation (P > 0.10). No significant changes in glucose, insulin or ketone body levels were observed in either group after supplementation. After fish oil, but not after olive oil supplementation, the ratio of blood ketone body levels to free fatty acid levels increased significantly (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Body composition in patients with acquired immunodeficiency syndrome: a validation study of bioelectric impedance analysis

The objective of this validation study was to explore bioelectric impedance analysis (BIA) as a way to assess nutritional status and body composition. The study was done in the outpatient department of the AIDS unit at University Hospital Dijkzigt, Rotterdam, The Netherlands. Eleven clinically stable patients with AIDS were studied. Total body water, body fat, lean body mass, and body cell mass were measured and calculated with multiple dilution techniques and BIA. With linear regression analysis, a strong correlation was found between total body water and lean body mass derived from BIA and multiple dilution techniques (r2 = .96 and .98, respectively), and slightly weaker correlation was found for body cell mass and body fat (r2 = .88 and .76, respectively). These results suggest that BIA is a suitable method for the assessment of body cell mass in HIV-infected patients without opportunistic infections. The technique is safe, noninvasive, fast, and inexpensive.

Nocturnal oral glucose supplementation. The effects on protein metabolism in cirrhotic patients and in healthy controls

Nocturnal glucose administration might prevent gluconeogenesis and concomitant protein loss due to hepatic glycogen depletion. In this study the effects of nocturnal oral glucose supplements on nitrogen metabolism were investigated in 8 cirrhotic patients and in 8 healthy controls. During the night, either polymeric glucose was given or water as placebo. In the patients with cirrhosis on placebo, nitrogen balance was not different from controls: -63 +/- 8 vs. -55 +/- 4 mg N/kg b.wt./9 h (mean +/- SEM). Cirrhotic patients had increased nocturnal protein turnover rates (measured with 15N-glycine) and increased early morning levels of free fatty acids (FFA), lactate, insulin, glucagon and growth hormone. After glucose, nitrogen balance improved by 36% in the cirrhotic group, with a decrease in protein turnover rates and a decrease in plasma levels of beta-hydroxybutyrate, urea and glucagon. In the controls, glucose had no effects on nitrogen balance, on protein turnover or on the hormone levels, except for reduced FFA and ketone body levels. These data show that nocturnal calorie supplements improve nitrogen balance during the night in cirrhotic patients but not in healthy controls. Long interprandial intervals should be avoided in cirrhotic patients.

The validity of bioelectrical impedance analysis in estimating total body water in patients with cirrhosis

This study assessed the validity of bioelectrical impedance analysis (BIA) to predict total body water (TBW) in patients with cirrhosis. TBW was estimated by deuterium oxide dilution (D2O) and compared with TBW predicted by BIA in 27 patients with cirrhosis with and without ascites or edema (Group A), in a subgroup of 18 'dry' cirrhotics without clinical signs of fluid overload (Group B) and in 27 healthy controls. Three different BIA regression equations were used. In all three groups of subjects high correlation coefficients were obtained between D2O-TBW and BIA-TBW (r > 0.88). In the cirrhotic Group A, BIA significantly underpredicted D2O-TBW by all 3 equations (2.9-3.8 l) and the regression lines were different from the lines of identity by two equations. Standard errors of estimate were high in Group A (3.04-3.97 l) in comparison with Group B (1.79-2.46 l) and the controls (1.03-1.41 l). In the 'dry' cirrhotics (Group B) and in the controls, TBW was correctly predicted by two of three BIA equations, and regression lines were not significantly different from lines of identity. Correlation coefficients in Group B were higher than in Group A (r = 0.96-0.97 vs. 0.89-0.92) and were comparable with controls (r = 0.98-0.99). We conclude that BIA is not a valid method of estimating TBW in cirrhotic patients with ascites and edema. In cirrhotic patients without clinical signs of fluid overload BIA can be used to predict TBW, although accuracy is slightly lower than in healthy controls.

Oral pharmacokinetics of cyclosporin in patients with primary biliary cirrhosis and patients with skin diseases

The pharmacokinetics of cyclosporin after oral administration were studied in seven patients with non-end stage primary biliary cirrhosis (PBC) without previous cyclosporin treatment (Group I), a control group of nine patients with skin diseases (mainly psoriasis; Group II) and six patients with PBC after prolonged cyclosporin treatment (Group III). Whole blood concentrations of cyclosporin were measured using a non-specific (N) radioimmunoassay (RIA) and--in a majority of the cases--also by a RIA specific (S) for the parent drug. No difference in cyclosporin absorption was observed between patients with PBC and those with a skin disease. The mean values for the area under the blood concentration-time curve for the first 6 h after the test dose (AUC0-6) and the maximal blood concentrations (Cmax) were significantly higher for Group I compared with Group II patients (P = 0.007 and 0.03, respectively), but the time to maximal blood concentrations (tc,max) did not differ. There was a trend toward higher mean AUC0-6 (P = 0.08) and Cmax (P = 0.08) values for Group III compared with Group I patients. Tc,max values were not influenced by prolonged cyclosporin treatment. The ratio of cyclosporin whole blood concentrations measured by the non-specific and specific RIA's (N/S ratio) increased with time without obvious differences between the three groups. These data suggest that cyclosporin absorption and its biotransformation in the liver are not impaired in patients with non-end stage PBC and that neither is affected by prolonged treatment.

Whole-body and segmental bioelectrical-impedance analysis in patients with cirrhosis of the liver: changes after treatment of ascites

Bioelectrical impedance analysis (BIA) is a simple technique for determining body water and calculating body composition. It has been validated in healthy control subjects but not in patients with liver disease. We examined the ability of BIA to detect changes in total body water (TBW) due to removal of ascites. In 12 cirrhotic patients, BIA of the whole body and of body segments was performed before and after treatment of ascites with paracentesis (n = 12) and diuretics (n = 2). TBW changes predicted by BIA, by using two prediction equations, were significantly less than body weight changes (51% and 45% of the weight loss). BIA of body segments showed highly significant changes in both the trunk and the leg and small changes in the arm. These data indicate that BIA of the whole body is not a suitable technique for monitoring fluid changes in cirrhotic patients with ascites. Changes in BIA of body segments may be due to mobilization of edema after the removal of ascites.

Primary bile acid malabsorption: a pathophysiologic and clinical entity?

Primary bile acid malabsorption is defined as chronic diarrhoea with bile acid malabsorption of unknown cause and a symptomatic response to cholestyramine. Convincing evidence of the proposed pathophysiology--a defect of the active bile acid absorption in the distal ileum--has never been substantiated. We found no evidence of a bile acid transport defect across the ileal brush border membrane in 10 patients with primary bile acid malabsorption; moreover, transport was significantly higher than in a control group. In the patients with primary bile acid malabsorption the estimated bile acid pool was significantly larger than in a control group and in a group of patients with ileal disease. In addition, the oro-anal transit time of radiopaque markers was shorter in the primary bile acid malabsorption group than in both other groups. This suggests that the bile acid pool size as well as intestinal motility could play a role in the pathophysiology of primary bile acid malabsorption.

Effects of ultraviolet B light on cutaneous immune responses of humans with deeply pigmented skin

The incidence of skin cancers of the basal and squamous cell types is extremely low among genetically black-skinned human beings, whereas these types of skin cancers are common among Caucasians, especially those who live in geographic areas of high sun exposure. Ultraviolet B light (UVB) is thought to be the primary oncogenic agent in sunlight. We have recently demonstrated that acute, low-dose exposure of Caucasian skin to UVB impairs the induction of contact hypersensitivity to dinitrochlorobenzene (DNCB) in approximately 40% of normal individuals. Importantly, this trait--termed UVB susceptibility--was found to be a characteristic of virtually 100% of patients with a history of biopsy-proved skin cancer, implying that UVB susceptibility may be a risk factor for this disease. Because melanin pigment is thought to be protective of some of the deleterious effects of UVB radiation, we have examined the capacity of a low-dose regimen of UVB to alter induction of contact hypersensitivity in individuals with genetically melanized or heavily tanned skin. Our results indicate that UVB radiation depletes heavily pigmented skin of Langerhans cells, just as it does in Caucasian skin. Moreover, UVB-susceptibility exists as a polymorphic trait in individuals with genetically determined black skin, as well as in individuals with heavily tanned skin, and the incidence of this trait is similar to that found among normal Caucasian subjects. Thus, melanin does not appear to protect against the deleterious effects of an acute, low-dose regimen of UVB on induction of cutaneous immunity, and the UVB susceptibility trait is equally well-represented in both black- and Caucasian-skinned individuals. We conclude that although UVB susceptibility may function as a risk factor for skin cancer in Caucasians, it does not function similarly in black-skinned human beings, probably because melanin effectively protects against the mutagenic properties of UVB radiation.

Cyclosporin A blood levels during use of cyclosporin as oral solution or in capsules: comparison of pharmacokinetic parameters

Recently cyclosporin A (CsA) capsules have been introduced to meet a number of disadvantages associated with the use of the oral solution. We compared the pharmacokinetics of the oral solution and the capsules in a group of nine renal transplant patients during the first 3 weeks after transplantation. After a morning dose of CsA, whole blood concentrations were measured at regular intervals for 12 h. Subsequently, a cross-over was made to the alternative form of administration, and 3 or 4 days later a second pharmacokinetic profile was obtained. Comparison of the trough level, the maximum concentration, the time to reach the maximal concentration and the area under the blood concentration curve, showed no significant differences. Our findings thus suggest a similar bioavailability of CsA administered as oral solution or in capsules in the early post-transplant period.

The selenium-75-homocholic acid taurine test reevaluated: combined measurement of fecal selenium-75 activity and 3 alpha-hydroxy bile acids in 211 patients

The recommended reference values for the selenium-75-homocholic acid taurine (75SeHCAT) test, used in the analysis of chronic diarrhea, were evaluated in 211 patients by comparing simultaneous measurements of 3 alpha-hydroxy bile acids and 75Se activity in daily collected stools. An initial evaluation in 11 patients showed that the fecal collection method, which allows inspection and additional analysis of stools, was equivalent to the abdominal retention method. Selenium-75-HCAT whole-body retention half-life (WBR50) was greater than 2.8 days in less than 10% of the patients with bile acid malabsorption and less than 1.7 days in less than 10% of the normals. We recommend that a 75SeHCAT WBR50 less than 1.7 days is abnormal, a WBR50 greater than 2.8 days is normal, and a WBR50 in the range 1.7-2.8 days is equivocal, which was the case in 48% (94/195) of the patients in this study.

Primary bile acid diarrhoea without an ileal carrier defect: quantification of active bile acid transport across the ileal brush border membrane

Unexplained bile acid malabsorption associated with diarrhoea that responds to cholestyramine was first described in 1973 but convincing evidence of the proposed mechanism--a defective active ileal bile acid transport--has never been substantiated. Active bile acid transport was quantified in vitro using brush border membrane vesicles prepared from terminal ileal biopsy specimens from 10 patients who fulfilled the criteria of idiopathic bile acid diarrhoea. They were recruited from 181 patients with bile acid malabsorption of various causes. Transport was quantified as in vitro Na+ dependent bile acid transport (INBAT), expressed as pmol taurocholate/mg brush border membrane protein/15 seconds, and in vitro Na+ dependent bile acid local transport capacity (INBALTC), expressed as pmol taurocholate/g ileal biopsy tissue/15 seconds. The lowest INBAT and INBALTC values in the 10 patients with idiopathic bile acid diarrhoea were well above the 10th centile values of a control group of 132 patients. Both INBAT (mean (range) 88 (30-136)) and INBALTC (158 (85-268)) values were significantly higher in the 10 patients than in the control group (INBAT: mean (range) 63 (1-244), INBALTC: mean (range) 98 (1-408)). Quantification of active ileal bile acid transport in these 10 patients with idiopathic bile acid malabsorption suggests that a genetic (carrier) defect is rare in adults.

Porphyrin synthesis by human hepatocytes and HepG2 cells--effects of enzyme inducers and delta-aminolevulinic acid

Experiments were carried out to investigate the possibility of inducing porphyria in human hepatocytes and HepG2 cells in culture. After treatment with hexachlorobenzene, 3-methylcholanthrene, phenobarbital or dimethyl sulfoxide, protoporphyrin was the predominating porphyrin accumulating in presence of delta-aminolevulinic acid. The typical uroporphyrin accumulation, as is seen in hexachlorobenzene-induced porphyria in vivo, was absent. In HepG2 cells, the activities of uroporphyrinogen decarboxylase and porphobilinogen deaminase were not influenced by cytochrome P-450 inducers, hexachlorobenzene or dimethyl sulfoxide during 48 h of culture. Therefore, the use of these cells in the study of porphyria cutanea tarda does not seem promising.

Photodynamic therapy for gastrointestinal tumors

Photodynamic therapy is based on the administration of a compound that is preferentially accumulated by a tumor and which causes tumor destruction after exposure to light of a specific wavelength. The photosensitizers most commonly used in treating tumors of the gastrointestinal tract are porphyrins--hematoporphyrin derivative and dihematoporphyrin ether. These compounds have been used with success to produce reduction in tumor size of esophageal, gastric, and colorectal cancers. In some instances long-lasting complete remission have been observed after photodynamic therapy. New developments include photosensitizers that react to light of a longer wavelength, which is able to penetrate tissue to a greater depth, the use of 5-aminolevulinic acid, which is preferentially converted to porphyrin in malignant cells, and combination of photodynamic therapy with thermic laser, radiotherapy, or chemotherapy.

Na+-dependent bile acid transport in the ileum: the balance between diarrhea and constipation

Ileal Na+-dependent bile acid transport was quantified in vitro as the uptake of 3H-taurocholate into brush-border membrane vesicles. Vesicles were prepared from ileal biopsies of 158 patients placed in 10 diagnostic categories. Active bile acid transport (expressed as picomoles taurocholate uptake per milligram brush-border membrane protein per 15 s, median and interquartile ranges indicated) did not differ significantly in 6 categories: irritable bowel syndrome (71, 35-97; n = 21), colon polyps (42, 30-89; n = 29), colitis (62, 33-91; n = 31), postvagotomy or postcholecystectomy (69, 37-97; n = 11), diarrhea without increased bile acid loss (58, 48-85; n = 12), and lack of gastrointestinal pathology (74, 45-103; n = 22). A decreased active bile acid transport was found in 3 categories: ileal disease (4, 1-36; n = 11), partial ileal resection (5, 1-35; n = 5), and constipation (41, 22-50; n = 8). Bile acid transport was increased in patients with bile acid-losing diarrhea with endoscopically and histologically normal ilea (111, 94-135; n = 8). These findings indicate that a low fecal bile acid loss, presumed to be present in constipated patients, is associated with a low Na+-dependent ileal bile acid transport and a high bile acid loss is associated with a high active bile acid transport. Ileal bile acid transport might be regulated by the availability of bile acids to the ileal enterocytes.

[75Se]-selenohomotaurocholic acid degradation by bacterial enzymes in vitro and in vivo. Is it still a specific indicator for active ileal bile acid uptake?

The stability of the bile acid analogue [75Se]-selenohomotaurocholic acid (75SeH-CAT) was studied in man. When 75SeHCAT was administered to patients for diagnostic purposes the majority of labeled material present in the feces was found deconjugated. In vitro incubation of 75SeHCAT, by addition of fecal homogenate or with addition of purified enzyme, showed identical deconjugation. The relative differences in polarities of 75SeHCAT, [75Se]-selenohomocholic acid (75SeHCA), [14C]-taurocholic acid (14C-TCA) and [14C]-cholic acid (14C-CA) were estimated by isoelectric focusing and selective chloroform extractions at various pH values. The pI values representing the pH where these molecules become uncharged were for 75SeHCA and 75SeHCAT 3.1, for 14C-TCA 3.0 and for 14C-CA 3.9. These results suggest that from these bile acids only 14C-CA is a candidate for passive absorption in the colon, while 75SeHCA would be far too polar for passive diffusion. Indeed, we could demonstrate the inability of 75SeHCA for passive absorption in healthy persons. In conclusion, 75SeHCAT, specifically selected to monitor active ileal bile acid transport, functions as a good indicator of this process in its conjugated form. In contrast to published data it is susceptible to bacterial degradation, and therefore gives rise to a diminished whole-body retention.

Effect of a late evening meal on nitrogen balance in patients with cirrhosis of the liver

OBJECTIVE

To assess whether a late evening meal would improve nitrogen balance in patients with cirrhosis of the liver.

DESIGN

Randomised crossover study of meal schedules comparing three meals a day with four or six meals a day, the four and six meal schedules both including a late evening meal (2300).

SETTING

Metabolic ward.

PATIENTS

Seven men and two women aged 34-66 with cirrhosis of the liver (Child's grade B).

INTERVENTIONS

Patients spent two seven day periods in the ward. For five days of each period they received, in random order, isonitrogenous isocaloric diets supplied in three meals a day and in four or six meals a day.

MAIN OUTCOME MEASURE

Nitrogen balance, calculated as the difference between dietary intake and the total of urinary, faecal, and integumental nitrogen loss.

RESULTS

Faecal nitrogen loss was no different between three meals a day and four or six meals a day. On both four and six meals a day, however, patients had nitrogen balances that were more positive (or less negative) than on three meals a day (1.26 (SD 2.1) g/24 h v 0.26 (2.2) g/24 h, p less than 0.01). Six meals a day did not produce significantly better improvements in nitrogen balance than four meals a day.

CONCLUSIONS

A late evening meal seemed to improve the efficiency of nitrogen metabolism, but longer term studies are needed to assess whether this leads to a better nutritional state.

Effects of the glucosidase inhibitor acarbose in patients with liver cirrhosis

In this preliminary study, we examined the effects of acarbose and placebo together with a standardized breakfast on blood glucose levels, on breath hydrogen excretion and on plasma insulin and glucagon levels; in addition, the effects on fasting blood levels of metabolites were studied following an evening meal with acarbose or placebo. Acarbose significantly reduced blood glucose levels in 10 patients with alcoholic cirrhosis following a meal containing 100 g of carbohydrate. There were no significant changes in plasma insulin after breakfast but glucagon levels were increased at 1 h after the meal. Breath hydrogen excretion did not change significantly. Acarbose given with a late evening snack reduced fasting beta-hydroxybutyrate levels the next morning in these cirrhotic patients.