Cumulative exposure to immunomodulators increases risk of cervical neoplasia in women with inflammatory bowel disease

BACKGROUND

Women with inflammatory bowel disease (IBD) are at increased risk of high-grade cervical intraepithelial neoplasia and cervical cancer (CIN2+).

AIM

To assess the association between cumulative exposure to immunomodulators (IM) and biologic agents (BIO) for IBD and CIN2+.

METHODS

Adult women diagnosed with IBD before December 31st 2016 in the Dutch IBD biobank with available cervical records in the nationwide cytopathology database were identified. CIN2+ incidence rates in IM (i.e. thiopurines, methotrexate, tacrolimus and cyclosporine) and BIO (anti-tumour necrosis factor, vedolizumab and ustekinumab) exposed patients were compared to unexposed patients and risk factors were assessed. Cumulative exposure to immunosuppressive drugs was evaluated in extended time-dependent Cox-regression models.

RESULTS

The study cohort comprised 1981 women with IBD, 99 (5%) developed CIN2+ during median follow-up of 17.2 years [IQR 14.6]. In total, 1305 (66%) women were exposed to immunosuppressive drugs (IM 58%, BIO 40%, IM and BIO 33%). CIN2+ risk increased per year exposure to IM (HR 1.16, 95% CI 1.08-1.25). No association between cumulative exposure to BIO or both BIO and IM and CIN2+ was observed. In multivariate analysis, smoking (HR 2.73, 95%CI 1.77-4.37) and 5-yearly screening frequency (HR 1.74, 95% CI 1.33-2.27) were also risk factors for CIN2+ detection.

CONCLUSION

Cumulative exposure to IM is associated with increased risk of CIN2+ in women with IBD. In addition to active counselling of IBD women to participate in cervical screening programs, further assessment of the benefit of intensified screening of women with IBD on long-term IM exposure is warranted.

Platelet-Rich stroma from Crohn's disease patients for treatment of perianal fistula shows a higher myeloid cell profile compared to non-IBD controls

BACKGROUND

New cell-based therapies are under investigation to improve perianal fistulizing Crohn's disease (pCD) healing. Autologous stromal vascular fraction combined with platelet-rich plasma (referred to as platelet-rich stroma [PRS]) is a new adipose-derived stromal therapy. The effect of Crohn's disease (CD) on adipose tissue, and adipose-derived therapies, is largely unknown. We characterized the cellular composition of subcutaneous lipoaspirate and PRS of pCD patients and non-Inflammatory Bowel Disease (IBD) controls.

METHODS

Consecutive pCD patients (≥18 years) and non-IBD controls, who underwent liposuction for the purpose of autologous PRS therapy, were included (October 2020 and March 2021). Mechanically fractionated lipoaspirate and the combined PRS product were analyzed for cell surface marker expression using fluorescence-activated cell sorting analysis.

RESULTS

Twenty-three patients (37.8 [IQR 30.7-45.0] years; 9 [39.1 %] male; 11CD patients) were included. Similar total number of cells were found in CD and non-IBD lipoaspirate (CD 8.23 ± 1.62*10⁵ cells/mL versus non-IBD 12.20 ± 3.39*10⁵). Presence of stromal cells, endothelial like cells, immune cells, T-cells, myeloid cells and M2/M1 macrophage ratio were similar in CD and non-IBD lipoaspirate. In PRS samples, more cells/mL were seen in CD patients (P = 0.030). Myeloid cells were more abundant in CD PRS samples (P = 0.007), and appeared to have a higher regulatory M2/M1 ratio. Interdonor variation was observed between lipoaspirate and PRS samples.

CONCLUSIONS

The composition of CD and non-IBD lipoaspirate were found to be similar and interdonor variation was observed. However, PRS from CD patients showed more myeloid cells with a regulatory phenotype. Crohn's disease does not appear to alter the immunological composition of adipose-derived products.

The diagnosis and management of CMV colitis in IBD patients shows high practice variation: a national survey among gastroenterologists

BACKGROUND

Clinical guidelines on cytomegalovirus (CMV) colitis in inflammatory bowel disease (IBD) are hampered by the low quality of evidence. In this study, we aim to explore the attitude and management of CMV colitis in IBD among gastroenterologists.

METHODS

A web-based survey was distributed to adult and pediatric gastroenterologists and trainees in academic and general hospitals in the Netherlands. The survey comprised data collection on respondents' demographics, attitudes towards the importance of CMV infection in IBD on a visual analogue scale (from 0 to 100), and diagnostic and therapeutic strategies.

RESULTS

A total of 73/131 invited respondents from 32 hospitals completed the survey (response rate of 56%). The importance of CMV infection was scored at a median 74/100. Respondents indicated CMV testing as appropriate in the clinical setting of steroid-refractory colitis (69% of respondents), hospitalized patients with active colitis (64%), immunomodulator or biological refractory colitis (55%) and active colitis irrespective of medication use (14%). CMV diagnostics include histology of colonic biopsies (88% of respondents), tissue CMV PCR (43%), serum CMV PCR (60%), CMV serology (25%) and fecal CMV PCR (4%). 82% of respondents start antiviral therapy after a positive CMV test on colonic biopsies (histology or PCR).

CONCLUSIONS

Most Dutch gastroenterologists acknowledge the importance of CMV colitis in IBD. Strategies vary greatly with regard to the indication for testing and diagnostic method, as well as indication for the start of antiviral therapy. These findings underline the need for pragmatic clinical studies on different management strategies, in order to reduce practice variation and improve the quality of care. Summary of the established knowledge on this subject:The clinical significance of CMV-associated colitis in IBD remains a matter of debateRecommendations regarding CMV colitis in current international guidelines are based on low to moderate evidence levels and different diagnostic strategies are proposed What are the significant and/or new findings of this study?We show that there is a high practice variation of diagnosis and management of CMV colitis in IBD amongst adult and pediatric gastroenterologistsThis study underlined the need for pragmatic studies and guidelines on different management strategies including cut-off values to start therapy.

Hepatitis E infection with a benign course during vedolizumab treatment for Crohn's disease: A case report

We present a 49 year old female patient with Crohn's disease (CD) in remission on vedolizumab therapy who experienced a symptomatic, though benign, course of acute hepatitis E. Routine blood tests showed substantial elevation of liver enzymes and polymerase chain reaction (PCR) testing confirmed hepatitis E virus (HEV) infection. Vedolizumab therapy was paused, liver enzymes improved three weeks after infection and normalized after six months. The patient recovered completely from mild symptoms. This case shows that hepatitis E is a potential cause of acute hepatitis during vedolizumab therapy, and in this case the infection has run a benign course.

Increased Risk of High-grade Cervical Neoplasia in Women with Inflammatory Bowel Disease: A Case-controlled Cohort Study

BACKGROUND AND AIMS

Women with inflammatory bowel disease [IBD] may be at higher risk for cervical intraepithelial neoplasia [CIN]. However, data are conflicting. The aim of this study was to assess the risk of high-grade dysplasia and cancer [CIN2+] in IBD women and identify risk factors.

METHODS

Clinical data from adult IBD women in a multicentre Dutch IBD prospective cohort [PSI] from 2007 onwards were linked to cervical cytology and histology records from the Dutch nationwide cytology and pathology database [PALGA], from 2000 to 2016. Patients were frequency-matched 1:4 to a general population cohort. Standardised detection rates [SDR] were calculated for CIN2+. Longitudinal data were assessed to calculate CIN2+ risk during follow-up using incidence rate ratios [IRR] and risk factors were identified in multivariable analysis.

RESULTS

Cervical records were available from 2098 IBD women [77%] and 8379 in the matched cohort; median follow-up was 13 years. CIN2+ detection rate was higher in the IBD cohort than in the matched cohort (SDR 1.27, 95% confidence interval [CI] 1.05-1.52). Women with IBD had an increased risk of CIN2+ [IRR 1.66, 95% CI 1.21-2.25] and persistent or recurrent CIN during follow-up (odds ratio [OR] 1.89, 95% CI 1.06-3.38). Risk factors for CIN2+ in IBD women were smoking and disease location (ileocolonic [L3] or upper gastrointestinal [GI] [L4]). CIN2+ risk was not associated with exposure to immunosuppressants.

CONCLUSIONS

Women with IBD are at increased risk for CIN2+ lesions. These results underline the importance of human papillomavirus [HPV] vaccination and adherence to cervical cancer screening guidelines in IBD women, regardless of exposure to immunosuppressants.

Lengthening adalimumab dosing interval in quiescent Crohn's disease patients: protocol for the pragmatic randomised non-inferiority LADI study

INTRODUCTION

Adalimumab is effective for maintenance of remission in patients with Crohn's disease (CD) at a dose of 40 mg subcutaneously every 2 weeks. However, adalimumab is associated with (long-term) adverse events and is costly. The aim of this study is to demonstrate non-inferiority and cost-effectiveness of disease activity guided adalimumab interval lengthening compared to standard dosing of every other week (EOW).

METHODS AND ANALYSIS

The Lengthening Adalimumab Dosing Interval (LADI) study is a pragmatic, multicentre, open label, randomised controlled non-inferiority trial. Non-inferiority is reached if the difference in cumulative incidence of persistent (>8 weeks) flares does not exceed the non-inferiority margin of 15%. 174 CD patients on adalimumab maintenance therapy in long-term (>9 months) clinical and biochemical remission will be included (C-reactive protein (CRP) <10 mg/L, faecal calprotectin (FC) <150 µg/g, Harvey-Bradshaw Index (HBI) <5). Patients will be randomised 2:1 into the intervention (adalimumab interval lengthening) or control group (adalimumab EOW). The intervention group will lengthen the adalimumab administration interval to every 3 weeks, and after 24 weeks to every 4 weeks. Clinical and biochemical disease activity will be monitored every 12 weeks by physician global assessment, HBI, CRP and FC. In case of disease flare, dosing will be increased. A flare is defined as two of three of the following criteria; FC>250 µg/g, CRP≥10 mg/l, HBI≥5. Secondary outcomes include cumulative incidence of transient flares, adverse events, predictors for successful dose reduction and cost-effectiveness.

ETHICS AND DISSEMINATION

The study is approved by the Medical Ethics Committee Arnhem-Nijmegen, the Netherlands (registration number NL58948.091.16). Results will be published in peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBERS

EudraCT registry (2016-003321-42); Clinicaltrials.gov registry (NCT03172377); Dutch trial registry (NTRID6417).

Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Non-obstetric surgery in pregnancy (including bowel surgery and gallbladder surgery)

Non-obstetric surgery during pregnancy is required in 0.75-2% of pregnancies. Physiologic changes during pregnancy, both hormonal and anatomic, can have interactions with surgery and anesthesia. Indication, timing as well as risks of anesthesia and surgery should be considered in surgical decision making. The health status of the mother should always be put first. A preoperative multidisciplinary approach, also including an obstetrician and neonatologist, is mandatory. Delay in diagnosis and treatment carry risks of complications in all septic visceral indications. Considerations should be individualized.

Clinical and endoscopic complications of Epstein-Barr virus in inflammatory bowel disease: an illustrative case series

BACKGROUND AND AIM

Epstein-Barr virus (EBV) is a proposed trigger in the etiopathogenesis of inflammatory bowel disease (IBD) and is associated with lymphoproliferative diseases. Nevertheless, testing for EBV DNA in the intestinal mucosa and screening for EBV infection before initiation of a drug therapy are not routinely performed. The aim of this article is to increase awareness of the relevance of EBV infection in specific clinical situations.

METHODS

In this short communication, we describe the disease course of three IBD patients with EBV infection, varying from EBV reactivation during disease flare up to a trigger of EBV-related mucocutaneous ulcer (EBV-MCU) and haemophagocytic lymphohistiocytosis (HLH).

RESULTS

Our first patient was diagnosed with EBV reactivation-associated severe colitis and showed a rapid clinical improvement after induction therapy with infliximab and azathioprine. Without antiviral treatment, the patient remained in complete remission and no complications of EBV were seen. After diagnosing EBV-MCU in the second patient, immunosuppressive medication was discontinued and four infusions of rituximab resulted in a rapid clinical recovery and eventually complete response. After discontinuation of the immunosuppression in our last patient with haemophagocytic lymphohistiocytosis, treatment with a combination of corticosteroid and antiviral therapy resulted in a complete recovery over a time span of several weeks.

CONCLUSION

EBV infection has a wide variety of potentially life-threatening clinical manifestations in IBD patients. Testing for EBV in case of a flare up and screening for EBV before the start of immunosuppressive therapy will create awareness for EBV-related symptoms or complications during follow-up.

Efficacy of tenofovir and efavirenz in combination with lamivudine or emtricitabine in antiretroviral-naive patients in Europe

BACKGROUND

The combination of tenofovir and efavirenz with either lamivudine or emtricitabine (TELE) has proved to be highly effective in clinical trials for first-line treatment of HIV-1 infection. However, limited data are available on its efficacy in routine clinical practice.

METHODS

A multicentre cohort study was performed in therapy-naive patients initiating ART with TELE before July 2009. Efficacy was studied using ITT (missing or switch = failure) and on-treatment (OT) analyses. Genotypic susceptibility scores (GSSs) were determined using the Stanford HIVdb algorithm.

RESULTS

Efficacy analysis of 1608 patients showed virological suppression to <50 copies/mL at 48 weeks in 91.5% (OT) and 70.6% (ITT). Almost a quarter of all patients (22.9%) had discontinued TELE at week 48, mainly due to CNS toxicity. Virological failure within 48 weeks was rarely observed (3.3%, n = 53). In multilevel, multivariate analysis, infection with subtype B (P = 0.011), baseline CD4 count <200 cells/mm³ (P < 0.001), GSS <3 (P = 0.002) and use of lamivudine (P < 0.001) were associated with a higher risk of virological failure. After exclusion of patients using co-formulated compounds, virological failure was still more often observed with lamivudine. Following virological failure, three-quarters of patients switched to a PI-based regimen with GSS <3. After 1 year of second-line therapy, viral load was suppressed to <50 copies/mL in 73.5% (OT).

CONCLUSIONS

In clinical practice, treatment failure on TELE regimens is relatively frequent due to toxicity. Virological failure is rare and more often observed with lamivudine than with emtricitabine. Following virological failure on TELE, PI-based second-line therapy was often successful despite GSS <3.

Persistent spiking fever in a child with acute myeloid leukemia and disseminated infection with enterovirus

We here report a 7 year old acute myeloid leukemia patient with persistent spiking fever likely caused by chronic echovirus 20 infection. After immunoglobulin substitution fevers subsided and the virus was cleared. Enterovirus infection should be considered in immunocompromised patients with unexplained persistent fever.

Preoperative risk information and patient involvement in surgical treatment for rectal and sigmoid cancer

AIM

Surgery for rectal and sigmoid cancer is a model setting for investigating preoperative information provision and shared decision making (SDM), as the decision consists of a trade-off between the pros and cons of different treatment options. The aim of this study was to explore surgeons' opinion on the preoperative information that should be given to rectal and sigmoid cancer patients and to evaluate what is actually communicated. In addition, we assessed surgeons' attitudes towards SDM and compared these with patient involvement.

METHOD

A questionnaire was sent to Dutch surgeons with an interest in gastroenterology. Preoperative consultations were recorded. A checklist was used to code the information that surgeons communicated to the patients. The OPTION-scale was used to measure patient involvement.

RESULTS

Questionnaires were sent to 240 surgeons, and 103 (43%) responded. They stated that information on anastomotic leakage and its consequences, the benefits and risks of a defunctioning stoma and the impact of a stoma on quality of life were necessary preoperative information. In practice, patients were inconsistently informed of these items. Most participants agreed to using SDM in their consultations. However, in practice, most patients were offered only one treatment option and little SDM was seen. The mean OPTION-score was low (7/100).

CONCLUSION

Insufficient information is given to patients with rectal and sigmoid cancer to guide them on their preferred surgical option. Information should be given on all treatment options, together with their complications and outcome, before any decision is made.

Follow-up of premalignant lesions in patients at risk for progression to gastric cancer

BACKGROUND AND STUDY AIMS

A recent international guideline recommends surveillance of premalignant gastric lesions for patients at risk of progression to gastric cancer. The aim of this study was to identify the role of the distribution and severity of premalignant lesions in risk categorization.

PATIENTS AND METHODS

Patients with a previous diagnosis of atrophic gastritis, intestinal metaplasia, or low grade dysplasia were invited for surveillance endoscopy with non-targeted biopsy sampling. Biopsy specimens were evaluated by pathologists (four general and one expert) using the Sydney and the operative link for gastric intestinal metaplasia (OLGIM) systems, and scores were compared using kappa statistics.

RESULTS

140 patients were included. In 37 % (95 % confidence interval [CI] 29 % - 45 %) the severity of premalignant lesions was less than at baseline, while 6 % (95 %CI 2 % - 10 %) showed progression to more severe lesions. Intestinal metaplasia in the corpus was most likely to progress to more than one location (57 %; 95 %CI 36 % - 76 %). The proportion of patients with multilocated premalignant lesions increased from 24 % at baseline to 31 % at surveillance (P = 0.014). Intestinal metaplasia was the premalignant lesion most frequently identified in subsequent endoscopies. Intestinal metaplasia regressed in 27 % compared with 44 % for atrophic gastritis and 100 % for low grade dysplasia. Interobserver agreement was excellent for intestinal metaplasia (k = 0.81), moderate for dysplasia (k = 0.42), and poor for atrophic gastritis (k < 0).

CONCLUSIONS

Premalignant gastric lesions found in the corpus have the highest risk of progression, especially intestinal metaplasia, which has excellent interobserver agreement. This supports the importance of intestinal metaplasia as marker for follow-up in patients with premalignant gastric lesions.

Cyclic loading of fractured cadaveric femurs after elastomer femoroplasty: an in vitro biomechanical study

BACKGROUND

Elastomer femoroplasty is a novel and experimental approach in the prevention of hip fracture surgery. Previously, we published the results of an in vitro cadaveric experiment in which we showed a significant reduction of fracture displacement in treated femurs. The aim of the present study was to establish the failure loads and inter-fragmentary movement of fractured, elastomer femoroplasty treated femurs during cyclic loading.

METHODS

16 cadaveric femurs were treated with elastomer femoroplasty and fractured in a simulated fall configuration. Each specimen underwent 10 cycles with a preload of 50 N, starting with a peak load of 250 N followed by 10 cycles of 500 N and continued with 500 N increments. The crosshead speed was 2 mm/s. The failure load, the number of completed cycles, and crosshead extensions were recorded.

FINDINGS

The mean failure load was 2709 N (SD 1094). The number of completed cycles until failure was 60 (SD 22). The mean translation during maximum loading was 5.25 mm (SD 0.9). At 1500 N (two times the bodyweight of a 75 kg individual) the extension was 3.16 mm.

INTERPRETATION

Preventive elastomer femoroplasty leads to the stabilization of the proximal femur after fracture. In a single leg stance configuration, cyclic loading with mean failure loads that well exceed the peak loads during normal gait is feasible.

Meta-analysis of the risk for anastomotic leakage, the postoperative mortality caused by leakage in relation to the overall postoperative mortality

BACKGROUND

Availability of anastomotic leakage rates and mortality rates following anastomotic leakage is essential when informing patients with rectal cancer preoperatively. We performed a meta-analysis of studies describing anastomotic leakage and the subsequent postoperative mortality in relation to the overall postoperative mortality after low anterior resection for rectal cancer.

METHODS

A systematic search was performed of the published literature. Data on the definition and incidence rate of AL, postoperative mortality caused by AL, and overall postoperative mortality were extracted. Data were pooled and a meta-analysis was performed.

RESULTS

Twenty-two studies with 10,343 patients in total were analyzed. Meta-analysis of the data showed an average AL rate of 9%, postoperative mortality caused by leakage of 0.7% and overall postoperative mortality of 2%. The studies showed variation in incidence, definition and measurement of all outcomes.

CONCLUSION

We found a considerable overall AL rate and a large contribution of AL to the overall postoperative mortality. The variability of definitions and measurement of AL, postoperative mortality caused by leakage and overall postoperative mortality may hinder providing reliable risk information. Large-scale audit programs may provide accurate and valid risk information which can be used for preoperative decision making.

Management of precancerous conditions and lesions in the stomach (MAPS): guideline from the European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter Study Group (EHSG), European Society of Pathology (ESP), and the Sociedade Portuguesa de Endoscopia Digestiva (SPED)

Atrophic gastritis, intestinal metaplasia, and epithelial dysplasia of the stomach are common and are associated with an increased risk for gastric cancer. In the absence of guidelines, there is wide disparity in the management of patients with these premalignant conditions. The European Society of Gastrointestinal Endoscopy (ESGE), the European Helicobacter Study Group (EHSG), the European Society of Pathology (ESP) and the Sociedade Portuguesa de Endoscopia Digestiva (SPED) have therefore combined efforts to develop evidence-based guidelines on the management of patients with precancerous conditions and lesions of the stomach (termed MAPS). A multidisciplinary group of 63 experts from 24 countries developed these recommendations by means of repeat online voting and a meeting in June 2011 in Porto, Portugal. The recommendations emphasize the increased cancer risk in patients with gastric atrophy and metaplasia, and the need for adequate staging in the case of high grade dysplasia, and they focus on treatment and surveillance indications and methods.

Elastomer femoroplasty prevents hip fracture displacement In vitro biomechanical study comparing two minimal invasive femoroplasty techniques

The purpose of this study was to test femur strength and the ability to prevent fracture displacement of two minimal invasive Elastomer femoroplasty techniques.

METHODS

A total of sixteen fixed human cadaveric femur pairs were used. From each pair one femur was randomly assigned for Elastomer femoroplasty. In these femora we drilled a 3.5mm entrance in the lateral cortex. Cavities for the Elastomer were created by: group A, balloon and group B an excentric drill. All femora were fractured by simulating a fall on the greater trochanter. Neck-shaft-angles on plain anterior posterior radiographs were measured to determine fracture displacement.

FINDINGS

There was no significant difference in fracture load between controls and treated femora for group A, 2904N (SD 1091) versus 2803N (SD 627) and group B, 2773N (SD 747) versus 2597N (SD 834). In group A the mean displacement was 35° (SD 14) for the control femora and 3° (SD 2) for the treated femora (P<0.001). In group B the mean displacement was 38° (SD 10) for the controls and 8° (SD 13) for the treated femora (P<0.001).

INTERPRETATION

The results of this study show that minimal invasive Elastomer femoroplasty prevents fracture displacement of the proximal femur. We found no significant compromise in load-to-fracture after minimal invasive balloon or excentric drill femoroplasty.

Helicobacter pylori eradication and gastric cancer: when is the horse out of the barn?

Helicobacter pylori infection is a major risk factor for gastric cancer development. Therefore, H. pylori eradication may be an important approach in the prevention of gastric cancer. However, long-term data proving the efficacy of this approach are lacking. This report describes two patients who developed gastric cancer at, respectively, 4 and 14 years after H. pylori eradication therapy. These patients were included in a study cohort of H. pylori-infected subjects who received anti-H. pylori therapy during the early years of development of H. pylori eradication therapy and underwent strict endoscopic follow-up for several years. In both patients, gastric ulcer disease and premalignant gastric lesions, i.e., intestinal metaplasia at baseline and dysplasia during follow-up, were diagnosed before gastric cancer development. These case reports demonstrate that H. pylori eradication does not prevent gastric cancer development in all infected patients after long-term follow-up. In patients with premalignant gastric lesions, in particular in patients with a history of gastric ulcer disease, adequate endoscopic follow-up is essential for early detection of gastric neoplasia.

Augmentation with silicone stabilizes proximal femur fractures: an in vitro biomechanical study

BACKGROUND

Prevention of hip fracture surgery in the elderly imposes great benefit for patient care as well as for society. The incidence of contra-lateral, second hip fractures after hip fracture surgery is as high as 20%. Augmentation of the contra-lateral proximal femur with silicone femoroplasty during hip fracture surgery of the ipsilateral hip could be a new preventive strategy. This study compared the degree of dislocation after a controlled induced fracture between treated and control cadaver femora.

METHODS

Ten paired cadaver femora were randomly assigned for silicone femoroplasty and biomechanically tested for fracture load and dislocation against their native contra-lateral control. A load testing machine was used for fracture induction. All femurs were first fractured in a simulated fall configuration followed by dislocation in a "single leg stance" configuration. Dislocation was accessed using the AO-classification and measuring the Caput-Collum-Diaphysis angle.

FINDINGS

Fracture loads were approximately 10% lower in the treated group (P=0.304). Forces needed to dislocate the proximal femur fractures did not significantly differ in both groups nor did the fracture type and AO-classification. All treated femurs showed complete reposition according to Caput-Collum-Diaphysis angle after dislocation versus only two of the controls (P<0.001).

INTERPRETATION

From the results of this study we conclude silicone femoroplasty stabilizes the proximal femur by restoring hip geometry according to the Caput-Collum-Diaphysis angle after fracture. Future improvements in minimal invasive excavation and injection could make silicone femoroplasty an attractive alternative strategy in the prevention of hip fracture surgery in the growing population of low-demand, elderly patients.

Gastric MALT lymphoma: epidemiology and high adenocarcinoma risk in a nation-wide study

BACKGROUND

Gastric marginal zone non-Hodgkin lymphomas MALT type (gMALT) and gastric adenocarcinomas (GC) are long-term complications of chronic Helicobacter pylori gastritis, however, the incidence of gMALT and the GC risk in these patients is unclear.

OBJECTIVE

To evaluate epidemiological time trends of gMALT in the Netherlands and to estimate GC risk.

METHODS

Patients with a first diagnosis of gMALT between 1991 and 2006 were identified in the Dutch nation-wide histopathology registry (PALGA). Age-standardised incidence rates were calculated. The incidences of GC in patients with gMALT and in the Dutch population were compared. Relative risks were calculated by a Poisson Model.

RESULTS

In total, 1419 patients were newly diagnosed with gMALT, compatible with an incidence of 0.41/100,000/year. GC was diagnosed in 34 (2.4%) patients of the cohort. Patients with gMALT had a sixfold increased risk for GC in comparison with the general population (p<0.001). This risk was 16.6 times higher in gMALT patients aged between 45 and 59 years than in the Dutch population (p<0.001).

CONCLUSIONS

GC risk in patients with gMALT is six times higher than in the Dutch population and warrants accurate re-evaluation after diagnosis and treatment for gMALT.

Epidemiological trends of pre-malignant gastric lesions: a long-term nationwide study in the Netherlands

BACKGROUND

The pre-malignant gastric lesions atrophic gastritis (AG), intestinal metaplasia (IM) and dysplasia (DYS) have long been identified as principal risk factors for gastric cancer.

OBJECTIVE

To evaluate epidemiological time trends of pre-malignant gastric lesions in the Netherlands.

METHODS

Patients with a first diagnosis of AG, IM or DYS between 1991 and 2005 were identified in the Dutch nationwide histopathology registry. The number of new diagnoses per year were evaluated relative to the total number of patients with a first gastric biopsy. Time trends were evaluated with age-period-cohort models using logistic regression analysis.

RESULTS

In total, 23 278 patients were newly diagnosed with AG, 65 937 patients with IM, and 8517 patients with DYS. The incidence of AG declined similarly in men and women with 8.2% per year [95% CI 7.9% to 8.6%], and DYS with 8.1% per year [95% CI 7.5% to 8.6%]. The proportional number of new IM cases declined with 2.9% per year [95% CI 2.7% to 3.1%] in men and 2.4% [95% CI 2.2% to 2.6%] in women. With age-period-cohort models a cohort phenomenon was demonstrated for all categories of pre-malignant gastric lesions in men and in women with IM and DYS. Period phenomena with a larger decline in number of diagnoses after 1996 were also demonstrated for AG and IM.

CONCLUSIONS

The incidence of pre-malignant gastric lesions is declining. Period and cohort phenomena were demonstrated for diagnoses of AG and IM. These findings imply that a further decrease of at least 24% in the incidence of gastric cancer in the coming decade may be anticipated in Western countries without specific intervention.

The detection, surveillance and treatment of premalignant gastric lesions related to Helicobacter pylori infection

Gastric cancer is an important worldwide health problem and causes considerable morbidity and mortality. It represents the second leading cause of cancer-related death worldwide. A cascade of recognizable precursor lesions precedes most distal gastric carcinomas. In this multistep model of gastric carcinogenesis, Helicobacter pylori causes chronic active inflammation of the gastric mucosa, which slowly progresses through the premalignant stages of atrophic gastritis, intestinal metaplasia and dysplasia to gastric carcinoma. Detection and treatment of premalignant lesions may thus provide a basis for gastric cancer prevention. However, at present, premalignant changes of the gastric mucosa are frequently disregarded in clinical practice or result in widely varying follow-up frequency or treatment. This review provides an overview of current knowledge on detection, surveillance and treatment of patients with premalignant gastric lesions, and identifies the uncertainties that require further research.

[Primary venous mesenterial thrombosis in three patients]

Three patients, a woman aged 72, a man aged 25 and a woman aged 42 years, presented at the casualty department with a subacute form of primary venous mesenterial thrombosis. As symptoms and laboratory findings are aspecific, CT scan is the gold standard for the diagnosis of this condition. In these patients no cause or predisposing factor was detected, so the disease was considered to be primary. Treatment generally consists of anticoagulant therapy and if peritonitis is present operation is indicated. Hyperdynamic circulation and inotropica are indicated after surgery and in cases of critical illness. Based on clinical findings the third patient was treated successfully with anticoagulants only. The other two also underwent partial small intestinal resection. All three patients were discharged in good health and were prescribed lifelong anticoagulants. If a cause of venous mesenterial thrombosis can be found, this must first be treated before deciding on whether lifelong treatment with anticoagulants is indicated.

[One hundred years of the Association of Surgeons in the Netherlands. VII. Vascular surgery]

The Dutch Society for Vascular Surgery was founded in 1981, as the first daughter of the Association of Surgeons in the Netherlands. Twenty years of vascular surgery show a broad perspective. Aside from the traditional handywork--central vascular reconstruction, bypass surgery (especially in the legs), and carotid surgery--, there have been many developments. Operations are less invasive and vascular surgeons are cooperating more and more intensively with other medical disciplines, especially radiology. Examples are the endovascular treatment of abdominal aortic aneurysm, in which an endoprosthesis is inserted via minute incisions in the groin by the vascular surgeon and an (interventional) radiologist together. In addition, interventions such as percutaneous transluminal angioplasty and stenting as well as new diagnostic possibilities (e.g. MRA) strengthen the cooperation with the radiologists. The multidisciplinary approach is also extremely important in other areas. Vascular surgeons team up with internal-medicine specialists (diabetes, hypertension, lipid metabolism disorders, thrombotic syndromes, etc.), rehabilitation specialists and podotherapists (in cases of diabetic foot and amputation), vascular laboratory technicians (diagnostics and follow-up by means of doppler and duplex techniques), and neurologists (cerebrovascular diseases). In the vascular centres, patients are treated effectively by a multidisciplinary team that draws up a plan for diagnosis and treatment. The two-year postgraduate course in vascular surgery is one of the tools used to guarantee and improve the high standard of quality. To this end, cooperation within Europe in the European Society for Vascular Surgery and the development and organisation of European examinations in vascular surgery are also of the essence.

Amaurosis fugax and stenosis of the ophthalmic artery--a case report

Amaurosis fugax has many causes. Its most common cause is transient hypoperfusion of the eye, caused by thromboemboli from atherosclerotic carotid arteries. Thromboembolism from carotid arteries is a risk factor for cerebral infarction, and preventive endarterectomy could be performed. This report describes a patient with a rare ophthalmic artery stenosis, which was the probable origin of thromboemboli. This finding prevented surgical intervention.

Complications of standard elective abdominal aortic aneurysm repair

OBJECTIVE

To evaluate complications of standard elective repair of infrarenal abdominal aortic aneurysms.

DESIGN

Prospective multicentre study.

MATERIALS

Two-hundred and ninety-one consecutive patients undergoing standard elective surgery for an infrarenal aortic aneurysm.

METHODS

Recording adverse events according to the recommendations of the Ad Hoc Committee on Reporting Standards.

RESULTS

Seventy-five patients (26%) experienced some complication following elective aortic aneurysm surgery. Twenty-two patients had a mild complication (7.6%, 95% C.I. 4.8-11.2%), 27 a moderate (9.3%, 95% C.I. 6.2-13.2%) and 26 patients had a severe and/or fatal complication (8.9%, 95% C.I. 5.9-12.8%). The in-hospital mortality was 4.1% (12 patients, 95% C.I. 2.2-7.1%). Cardiac failure was the commonest primary cause for death (58%). Twenty-two per cent of the patients had a non-fatal complication: the most frequent being pulmonary (10%) and cardiac (10%). Patients with a history of cardiac events had a five times higher risk of a fatal outcome (95% C.I. 1.1-24.0) and a two and a half times higher risk of any severe fatal or non-fatal complication (95% C.I. 1.0-6.5). Other risk factors were advancing age and the presence of pulmonary disease.

CONCLUSIONS

In addition to mortality, morbidity figures of standard aneurysm operations are important, as well as associated risk factors. This is especially true when evaluating early repair of small aneurysms and new endovascular techniques.

Quadratus femoris tendinitis as a cause of groin pain

Images

Neuromuscular disorders in patients with intermittent claudication

OBJECTIVE

To evaluate the effect of claudication on nerve function in patients with unilateral peripheral arterial disease.

DESIGN

Prospective study.

SETTING

District hospital, The Netherlands.

SUBJECTS

11 Patients with unilateral intermittent claudication (diagnosed from history and ankle-brachial blood pressure index) underwent electrophysiological studies of both legs, including nerve conduction velocities, motor unit action potentials, H-reflex measurements, and muscle strength testing. The asymptomatic leg was used as the control in each case.

RESULTS

Six patients had neuropathy in both the claudicating and the control leg. Three other patients had neuropathy in the claudicating leg only, which consisted mainly of disorders of nerve conduction including the H-reflex. There was no clear difference between muscle strength in the symptomatic and control legs, possibly because more than half the patients studied, had neuropathy in both legs.

CONCLUSIONS

Neuropathy is common at an early stage of arterial disease and could be one of the factors leading to impaired muscle function in such patients.

Mortality rates associated with operative treatment of infrarenal abdominal aortic aneurysm in The Netherlands

Information on surgery for non-ruptured and ruptured infrarenal abdominal aortic aneurysm (AAA) in all hospitals in The Netherlands in 1990 was obtained from the Dutch National Medical Registration Foundation. The operation rate in the population over the age of 50 years was 30.3 per 100,000 for non-ruptured AAA and 16.8 per 100,000 for ruptured aneurysm. The hospital operative mortality rate for non-ruptured AAA surgery was 6.8 per cent in 1289 patients and for ruptured aneurysm 43.6 per cent in 709. For non-ruptured AAA the mortality rate almost doubled per age group of 10 years, whereas the influence of age was less significant for ruptured lesions. The operative mortality rate for non-ruptured aneurysm in university hospitals exceeded that in other hospitals, but no difference was found for emergency surgery on ruptured AAA. Nationwide results give a more representative picture of the true mortality rate associated with operation for aortic aneurysm. Such data are important for planning future treatment strategy and for evaluating the efficacy of screening.

Accuracy of ultrasonographic measurement of infrarenal abdominal aortic aneurysm

The ultrasonographic measurement of abdominal aortic aneurysm (AAA) must be accurate as the decision on elective repair will usually be based on such results. To detect expansion, measurements must be comparable. The interobserver variation of ultrasonographic measurement of infrarenal aortic aneurysms under standardized conditions is described.

Different effects of the hypolipidemic drugs pravastatin and lovastatin on the cholesterol biosynthesis of the human ocular lens in organ culture and on the cholesterol content of the rat lens in vivo

This study aimed to investigate the influence of the hypocholesterolemic drugs pravastatin and lovastatin on the cholesterol biosynthesis in the ocular lens. Two model systems were used: a human lens organ culture system and an in vivo rat lens system. For measurements of cholesterol and fatty acid synthesis rates, human lenses were incubated for 20 h in the presence of [14C]acetate. Pravastatin and lovastatin were added 1 h prior to the addition of the radioactive label. In order to avoid the influence of differences relating to individual donors, one lens from each donor was incubated without drug (control) and the other lens was incubated in the presence of the drug. Statistical analysis showed that the fatty acid synthesis rate was not influenced by the drug. For each lens pair the percentage inhibition of the cholesterol synthesis caused by the drug was calculated. Using various concentrations of the drugs, a dose-response curve was composed for the inhibition of the cholesterol synthesis. The experiments showed that in the human lens organ culture system, lovastatin was 100-fold more potent than pravastatin in inhibiting the cholesterol biosynthesis. To study the in vivo influence of vastatins on the cholesterol content of the developing lens, Wistar rats were weaned at day 21 of age and subsequently the pups were fed a control diet or drug-containing diet (10, 50 or 100 mg lovastatin/kg chow) for a 3-week period. At the end of diet intervention, doses of 50 or 100 mg lovastatin/kg chow had caused a reduction of about 20% of the lenticular cholesterol content compared with controls. No effect on the lens cholesterol content by pravastatin was observed. Both human ex vivo and rat in vivo experiments show that lovastatin much more strongly inhibits the lenticular cholesterol synthesis than does pravastatin.

Pravastatin and simvastatin differently inhibit cholesterol biosynthesis in human lens

PURPOSE

In the current study, the hypocholesterolemic drugs pravastatin and simvastatin were compared for their influence on cholesterol biosynthesis in the human lens.

METHODS

For measurements of cholesterol and fatty acid synthesis rates, human lenses were incubated for 20 hr in the presence of [14C]-acetate, and pravastatin or simvastatin. Radiolabeled [14C]-cholesterol and [14C]-fatty acids were determined. To avoid the influence of individual differences, one lens from each donor was incubated without drug (control) and the other lens was incubated in the presence of drug. For each lens pair, the percentage inhibition of the cholesterol synthesis caused by the drug was calculated. Fatty acid synthesis was not influenced by the drugs. By comparing the fatty acid synthesis rate of the drug-incubated with the control lens of a pair, a predefined exclusion criterion was used to eliminate lens pairs in which the lenses had no comparable biosynthetic capacities.

RESULTS

Using various concentrations of the drugs, a dose-response curve was constructed for the inhibition of the cholesterol synthesis. The IC50 values (drug concentration give 50% inhibition) were 0.5 mumol/l and 0.004 mumol/l for pravastatin and simvastatin, respectively. 3-Hydroxy-3-methylglutaryl coenzyme A reductase activity in microsomal membranes from human lens cortex was inhibited by simvastatin and pravastatin to the same extent.

CONCLUSIONS

Under the conditions used in this study, cholesterol synthesis in human lenses is inhibited by simvastatin 100-fold more effectively than by pravastatin. This difference was likely due to differences in the intracellular exposure of the reductase to the drugs in intact human lenses.

Eosinophilic enteritis presenting as acute abdomen: US features of two cases

Eosinophilic enteritis is a rare disease which may mimic acute abdominal emergency. Two sonographically documented cases are presented, which were subsequently proven at operation. Although the sonographic features of severe echolucent bowel wall thickening were not specific, combination with clinical and laboratory data may suggest the correct diagnosis.

[Abdominal aortic aneurysm as incidental finding in abdominal ultrasonography]

Abdominal aortic aneurysm is a life-threatening condition, which usually remains without symptoms until rupture occurs. The only way to reduce the high mortality rate (estimated at over 80%) is elective surgery on suitable patients. Therefore the presence of such an aneurysm has to be detected. For this ultrasonography is the method of choice. We studied 4399 consecutive patients aged 50 years and older, who underwent abdominal ultrasonography for the first time. According to the recommendation of the Dutch Society for Radiodiagnostics the whole abdomen was screened. In 4026 patients (1717 men and 2309 women) the ultrasound examination was performed for non-vascular reasons. In 199 of these patients (4.9%) an abdominal aortic aneurysm was an adventitious finding (133 men (7.7%) and 66 women (2.9%)). In men aged 60 years and older it was even found in 10.2%. When abdominal ultrasonography is performed for the first time in a patient aged 50 years or older, the aorta has to be screened for presence of an aneurysm.

[A patient with Salmonella aortitis]

Bacterial aortitis is a rare but serious condition. Even when treated surgically, the prognosis is poor. Prompt diagnosis is mandatory. In the absence of specific clinical signs, radiological assessment by means of ultrasound and CT is most valuable. The treatment of choice is early surgical drainage, debridement and arterial reconstruction, preferably through uncontaminated tissue combined with antibiotic therapy. We report the case of a man aged 80 with Salmonella aortitis in whom the diagnosis of bacterial aortitis was made by means of ultrasound and CT, following which successful intervention was carried out.

Biosynthetic capacity of the human lens upon aging

Lipid and protein biosynthesis were investigated in organ culture of human lenses from subjects ranging from 8 to 95 years old. A marked increase of protein and cholesterol content of the human lens with age was found. No significant linear correlation of age with either cholesterol or fatty acid synthesis was observed. Moreover, there are no indications that either synthesis declines with increasing age of the subject. Notwithstanding the large variety in age of the subjects, cholesterol and fatty acid synthesis of the individual lenses were correlated with each other in a positive linear way. Non-cataractous lenses as old as 80 years revealed a normal protein synthesis pattern as determined by incorporation of [35S]methionine into protein and analysis by 2D-gel electrophoresis. In addition, they maintained a high protein biosynthetic capacity.

Abdominal aortic aneurysm as an incidental finding in abdominal ultrasonography

The difference between the mortality rate from ruptured abdominal aortic aneurysm (overall mortality rate 85-95 per cent and operative mortality rate 23-63 per cent), and that for elective aneurysm repair (less than 5 per cent) is dramatic. Awareness of the existence of an abdominal aortic aneurysm is therefore essential. Of 1800 consecutive patients aged greater than or equal to 50 years referred for their first abdominal ultrasonography, 113 who had been referred specifically for suspected abdominal aortic aneurysm or vascular screening were excluded. The remaining 1687 patients (693 men and 994 women) form the study group. Apart from the symptom-directed examination, the entire abdomen of every patient was routinely studied by ultrasonography. The definition of an abdominal aortic aneurysm was a local dilatation of the aorta with an anteroposterior diameter greater than 30 mm or greater than 1.5 times the anteroposterior diameter of the proximal aorta. In 82 cases (4.9 per cent) an abdominal aortic aneurysm was disclosed; 61 were in men (8.8 per cent) and 21 were in women (2.1 per cent). The prevalence of abdominal aortic aneurysm as an incidental finding in men aged greater than or equal to 60 years was 11.4 per cent. In every patient aged greater than or equal to 50 years undergoing their first abdominal ultrasonography examination, the aorta should be screened for the presence of an aneurysm.

Should proximal saphenous vein be used for carotid patch angioplasty: a clinical study of the need for vein in subsequent operations

Reluctance to use saphenous vein (SV) for patch closure of the carotid arteriotomy is due in part to the concern of vascular surgeons that the SV should be preserved for possible future coronary or lower extremity reconstruction. Even among those who favour vein patch closure of the arteriotomy for improved immediate and late results, an effort has been made to use the ankle portion of the SV, preserving the upper, larger segment for later surgery. Recent reports of rupture of the patches formed from ankle SV and a study showing a decrease in strength of the ankle segment of vein, raised the question of the importance of trying to preserve the proximal SV and the impact of use of this segment in those patients requiring secondary vascular procedures. We reviewed 134 consecutive carotid patients from 1981 who had proximal SV harvested for patch angioplasty. Of those 122 were available (mean 44.9 months). Thirteen had secondary vascular procedures. Adequate saphenous vein was available in twelve. We conclude from this study that (1) less than 15% of patients undergoing carotid surgery will require a secondary vascular surgery within 5 years and (2) harvesting SV from the thigh rarely compromises future revascularisation.

Carotidynia managed by surgical denervation of the carotid bulb

Carotidynia is a syndrome of pain in the neck and face accompanied by local tenderness of the carotid artery. The symptoms are often misdiagnosed due to similarities with more common syndromes involving the cervical region. Spontaneous remission is common; more severe cases generally respond to anti-inflammatory medication or prophylactic drugs used for migraine. A case of severe carotidynia, unassociated with migraine is reported. Failure to respond to medical therapy led to surgical denervation of the carotid bulb. The immediate relief of symptoms following surgery confirms earlier observations regarding the mechanism of the symptoms. In severe cases of carotidynia, surgical denervation of the carotid artery may be indicated if medical therapy has failed.

Isolation and characterization of boar spermatozoa with and without a cytoplasmic droplet

1. Boar semen was separated on a Percoll density gradient into three populations; a low-density band of immature sperm cells containing a cytoplasmic droplet and a high-density doublet band formed by spermatozoa without a cytoplasmic droplet. 2. In these three cell populations four acid hydrolases were determined, viz. (1) alpha-glucosidase; (2) alpha-mannosidase; (3) beta-galactosidase; (4) beta-hexosaminidase. 3. The release of the hydrolases (1), (2) and (3) from cytoplasmic droplet containing spermatozoa was stimulated whereas the release of beta-hexosaminidase was inhibited by calcium ions. 4. The results suggest that acid alpha-glucosidase, alpha-mannosidase and beta-galactosidase are situated in the acrosome whereas acid beta-hexosaminidase is localized predominantly in the cytoplasmic droplet of boar spermatozoa. 5. We conclude that beta-hexosaminidase should prove useful as a biochemical marker for cytoplasmic droplet containing spermatozoa and hence for the number of immature sperm cells in boar semen.

An improved procedure for the isolation of lamellar bodies from human lung. Lamellar bodies free of lysosomes contain a spectrum of lysosomal-type hydrolases

We have recently shown that lamellar body fractions purified from human lung contain a distinct acid alpha-glucosidase distinguishable from lysosomal acid alpha-glucosidase in that it does not cross-react with antibodies raised against the lysosomal enzyme and does not bind to concanavalin A (De Vries, A.C.J., Schram, A.W., Tager, J.M., Batenburg, J.J. and Van Golde, L.M.G. (1985) Biochim. Biophys. Acta 837, 230-238). In order to study the relationship between the non-concanavalin A-binding alpha-glucosidase and lamellar bodies more closely a method was developed for the further purification of the organelles. A purified lamellar body preparation isolated from human lung homogenate by discontinuous sucrose density centrifugation was subjected to gel filtration with Sepharose 4B followed by Percoll density gradient centrifugation, which yielded a lamellar body preparation with a phospholipid phosphorus/protein ratio of 12.57 +/- 0.38 (mumol/mg) (n = 3) as compared to a ratio of 3.34 +/- 0.16 (mumol/mg) (n = 3) in the sucrose density gradient preparation. Concomitantly there was a 3.3 +/- 0.1 (n = 3)-fold enrichment in the content of total acid alpha-glucosidase and a 3.2 +/- 0.1 (n = 3) -fold enrichment of non-concanavalin A-binding acid alpha-glucosidase. The new purification method removes adhering proteins without changing the phospholipid composition. During the successive purification steps the concanavalin A-sensitive and -insensitive alpha-glucosidases remained fully lamellar body fraction associated. Differences between a lysosome-enriched fraction and a lamellar body preparation at varying stages of purification with respect to the ratio between soluble acid hydrolases and the membrane-associated lysosomal enzyme glucocerebrosidase indicate that the purified lamellar bodies were not contaminated with lysosomes. The absence of lysosomes in the purified lamellar body fraction was confirmed by experiments with the weak base glycyl-L-phenylalanine-beta-naphthylamide, which is an artificial substrate for the lysosomal enzyme cathepsin C and brings about lysis of lysosomes. Morphological examination by electron microscopy endorses the absence of contaminating vesicles and organelles and showed a structural integrity of the lamellar bodies in the final preparation. The improved isolation procedure strongly suggests that the concanavalin A-insensitive acid alpha-glucosidase is endogenous to lamellar bodies and supports our earlier idea that it can be used as a lamellar body-specific marker enzyme. In addition, the experiments show that lamellar bodies free of lysosomes contain a spectrum of lysosomal-type enzymes.

Genetic relationship between lysosomal and lamellar body-specific alpha-glucosidases in human lung

In lamellar bodies isolated from adult human lung at least two acid alpha-glucosidases are present: one similar to the lung lysosomal alpha-glucosidase, and another lamellar body-specific isoenzyme. In the present study we measured the activity of this lamellar body-specific alpha-glucosidase and of lysosomal alpha-glucosidase in a patient with an inherited deficiency of lysosomal alpha-glucosidase. The activity of the lamellar body-specific alpha-glucosidase was not affected in the patient, whereas the lysosomal alpha-glucosidase activity was strongly depressed. The results strongly suggest that the lysosomal alpha-glucosidase and the lamellar body-specific alpha-glucosidase are different gene products.

A specific acid alpha-glucosidase in lamellar bodies of the human lung

In the present investigation, we have demonstrated that three lysosomal-type hydrolases, alpha-glucosidase, alpha-mannosidase and a phosphatase, are present in lamellar bodies isolated from adult human lung. The hydrolase activities that were studied, all showed an acidic pH optimum, which is characteristic for lysosomal enzymes. The properties of acid alpha-glucosidase in the lamellar body fraction and that in the lysosome-enriched fraction were compared. Using specific antibodies against lysosomal alpha-glucosidase from human placenta, two alpha-glucosidases could be distinguished in the lamellar body fraction: one with a high affinity to the antibodies as found in the lysosome-enriched fraction and another with a much lower affinity. Both forms showed an acidic pH optimum. The same heterogeneity of alpha-glucosidase in the lamellar body fraction could be observed using immobilized concanavalin A. The lectin was able to precipitate nearly all alpha-glucosidase activity of the lysosome-enriched fraction. In contrast, 30% of the alpha-glucosidase activity in the lamellar body fraction was not precipitable. Furthermore, the lamellar body alpha-glucosidase with the low antibody affinity could not be bound to concanavalin A. The results suggest that lamellar bodies contain at least two acid alpha-glucosidases: one similar to the lung lysosomal alpha-glucosidase, and another lamellar body-specific isoenzyme with a different immunoreactivity and lectin affinity. The lamellar body-specific alpha-glucosidase should prove useful as a lamellar body-specific marker enzyme.