Mitochondrial C5aR1 activity in macrophages controls IL-1β production underlying sterile inflammation

While serum-circulating complement destroys invading pathogens, intracellularly active complement, termed the “complosome,” functions as a vital orchestrator of cell-metabolic events underlying T cell effector responses. Whether intracellular complement is also nonredundant for the activity of myeloid immune cells is currently unknown. Here, we show that monocytes and macrophages constitutively express complement component (C) 5 and generate autocrine C5a via formation of an intracellular C5 convertase. Cholesterol crystal sensing by macrophages induced C5aR1 signaling on mitochondrial membranes, which shifted ATP production via reverse electron chain flux toward reactive oxygen species generation and anaerobic glycolysis to favor IL-1β production, both at the transcriptional level and processing of pro–IL-1β. Consequently, atherosclerosis-prone mice lacking macrophage-specific C5ar1 had ameliorated cardiovascular disease on a high-cholesterol diet. Conversely, inflammatory gene signatures and IL-1β produced by cells in unstable atherosclerotic plaques of patients were normalized by a specific cell-permeable C5aR1 antagonist. Deficiency of the macrophage cell-autonomous C5 system also protected mice from crystal nephropathy mediated by folic acid. These data demonstrate the unexpected intracellular formation of a C5 convertase and identify C5aR1 as a direct modulator of mitochondrial function and inflammatory output from myeloid cells. Together, these findings suggest that the complosome is a contributor to the biologic processes underlying sterile inflammation and indicate that targeting this system could be beneficial in macrophage-dependent diseases, such as atherosclerosis.

Mitral annulus disjunction is associated with adverse outcome in patients with Marfan syndrome and Loeys-Dietz syndrome

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Background

Mitral valve prolapse is a common finding in patients with Marfan (MFS) and Loeys-Dietz syndromes (LDS). Mitral annulus disjunction (MAD) is an atrial displacement of the hinge point of the mitral valve that frequently coexists with mitral valve prolapse, but its clinical relevance in connective tissue disorders is unknown.

Purpose

To explore the association between MAD and severity of mitral valve and aortic disease in patients with MFS and LDS.

Methods

We included consecutive MFS patients and LDS patients fulfilling established diagnostic criteria. MAD was identified by echocardiography and defined as the distance from the ventricular myocardium to the hinge point of the posterior mitral leaflet (Figure, panel A). Aortic surgery was defined as emergency surgery for aortic dissection or prophylactic aortic surgery for aortic aneurysm. We recorded the need of mitral valve surgery including mitral valve repair or replacement.

Results

We included 168 patients of whom 103 (61%) had MFS and 65 (39%) had LDS. We identified MAD in 69 (41%) patients. Aortic surgery was performed in 112 (67%) patients (27 dissections and 85 prophylactic interventions). Patients with MAD were younger at the time of aortic surgery than those without MAD (p log rank = 0.02) (Figure, panel B). Patients needing aortic surgery had greater MAD distance (8 [7-10] mm vs. 7 [6-8] mm, p = 0.04). Mitral valve surgery was performed in 12 (7%) patients, more frequently in patients with MAD than in those without (16% vs. 1%, p < 0.001, p log rank < 0.001) (Figure, panel C).

Conclusion

MAD was frequent and detected in 41% of patients with MFS and LDS. MAD was associated with a more severe disease phenotype including aortic surgery at younger age and frequent need for mitral valve surgery. Screening patients with MFS and LDS for MAD may provide prognostic information and may be relevant in planning surgical interventions.

Abstract Figure

Mitral annulus disjunction is highly prevalent in patients with Marfan syndrome and Loyes-Dietz syndrome

Background

Mitral valve prolapse is a common finding in patients with Marfan and Loyes-Dietz syndrome. Mitral annulus disjunction (MAD), an atrial displacement of the hinge point of the mitral valve, has previously been associated with non-syndromic MVP and life-threatening ventricular arrhythmias.

Purpose

We aimed to assess the prevalence of MAD in patients with Marfan and Loyes-Dietz syndrome and relate the presence of MAD to mitral valve prolapse.

Methods

We included genotype positive patients with Marfan and Loyes-Dietz syndrome, and patients with Marfan syndrome fulfilling Revised Ghent Criteria. Mitral valve prolapse was defined as superior mitral leaflets' displacement ≥2mm beyond the mitral annulus. MAD was diagnosed by echocardiography and quantified as the distance from the ventricular myocardium to the hinge point of the posterior mitral leaflet (Figure, left panel).

Results

We included 111 patients with Marfan syndrome and 66 patients with Loyes-Dietz syndrome (age 26 [IQR, 13–39] years, 53% male). Mitral valve prolapse was observed in 54 (31%) and MAD in 74 (42%) patients. Longitudinal MAD distance was 8 (IQR, 6–10) mm. Forty-six (85%) patients with mitral valve prolapse had concomitant MAD, p<0.001 (Figure, right panel).

Conclusion

Mitral valve prolapse was observed in one third of patients with Marfan and Loyes-Dietz syndrome. MAD was highly prevalent and found in 42% of all patients and in 85% of those with mitral valve prolapse. Presence of mitral valve prolapse in Marfan and Loyes-Dietz syndrome should raise awareness of MAD which may be of importance in follow-up and monitoring of these patients.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Health Authority of South Eastern Norway

Reduced display of conformational epitopes in the N-terminal truncated GAD65 isoform: relevance for people with stiff person syndrome or DQ8/8-positive Type 1 diabetes mellitus

AIMS

To investigate whether the N-terminal truncated glutamic acid decarboxylase 65 (GAD65) isoform is as well recognized by people with stiff person syndrome as it is by people with Type 1 diabetes, and whether conformational GAD65 antibody epitopes are displayed properly by the isoform.

METHODS

GAD65 antibody-positive healthy individuals (n=13), people with stiff-person syndrome (n=15) and children with new-onset Type 1 diabetes (n=654) were analysed to determine binding to full-length GAD65 and the N-terminal truncated GAD65 isoform in each of these settings. GAD65 autoantibody epitope specificity was correlated with binding ratios of full-length GAD65/N-terminal truncated GAD65.

RESULTS

The N-terminal truncated GAD65 isoform was significantly less recognized in GAD65Ab-positive people with stiff-person syndrome (P=0.002) and in healthy individuals (P=0.0001) than in people with Type 1 diabetes. Moreover, at least two specific conformational GAD65Ab epitopes were not, or were only partially, presented by the N-terminal truncated GAD65 isoform compared to full-length GAD65. Finally, an N-terminal conformational GAD65Ab epitope was significantly less recognized in DQ8/8 positive individuals with Type 1 diabetes (P=0.02).

CONCLUSIONS

In people with stiff person syndrome preferred binding to the full-length GAD65 isoform over the N-terminal truncated molecule was observed. This binding characteristic is probably attributable to reduced presentation of two conformational epitopes by the N-terminal truncated molecule. These findings support the notion of disease-specific GAD65Ab epitope specificities and emphasize the need to evaluate the applicability of novel assays for different medical conditions.

Carotid Plaque Neovascularization Detected With Superb Microvascular Imaging Ultrasound Without Using Contrast Media

Background and Purpose- A significant proportion of ischemic strokes are caused by emboli from unstable carotid artery plaques with intraplaque neovascularization (IPN) as a key feature of plaque instability. IPN is not detectable with conventional Doppler ultrasound. Contrast-enhanced ultrasound (CEUS) can visualize IPN, but its use is limited in clinical practice because it requires an intravenous injection of contrast. Superb microvascular imaging (SMI) without contrast uses an algorithm to remove clutter and motion wall artifacts while preserving low-velocity blood flow signals, enabling visualization of IPN. Our aim was to assess the feasibility of SMI for the detection of IPN. Methods- Thirty-one patients with >50% carotid stenosis were included: 22 patients were symptomatic and 9 asymptomatic. All patients underwent conventional carotid ultrasound, CEUS, SMI, and blood tests. CEUS and SMI findings were compared and correlated to histological plaque assessments after endarterectomy. Results- There was significant positive correlation between an IPN visual 5-level classification of SMI and a semiquantitative analysis of CEUS (P<0.001, r=0.911). Plaques with higher SMI grades had higher numbers of neovessels quantified at histology (P=0.041, r=0.460). Hypoechoic plaques had higher grades of IPN on both CEUS and SMI (P<0.001). Higher visual IPN counts on SMI were associated with (1) increased areas of inflammation (P=0.043, r=0.457), (2) combined rank scores of granulation tissue, inflammation and lipids (P=0.02, r=0.494) at histology, and (3) higher peak-intensity values on quantitative CEUS (P=0.042, r=0.514). Conclusions- SMI ultrasound can detect neovascularization with accuracy comparable to CEUS, suggesting SMI to be a promising noninvasive alternative to CEUS for the assessment of carotid plaque stability.

Results after sacral nerve stimulation for chronic constipation

BACKGROUND

Sacral nerve stimulation is an established treatment for fecal incontinence and initial reports describe successful results also in subjects with chronic constipation.

METHODS

Consecutive patients with slow transit or outlet obstruction type constipation were offered external stimulation through a test electrode inserted in a sacral foramen during a 3-week period. The symptomatic evaluation was based on the number of bowel movements and a validated obstructed defecation score (ODS). A permanent implant was performed provided an overall 50% decrease in symptoms was observed.

KEY RESULTS

In total, 44 patients with chronic constipation were treated with a 3-week test stimulation. Fifteen experienced a 50% reduction of symptoms and received a permanent implant. Four of the 15 with permanent implants were explanted during the course of the study. Five subjects (11% of original group) reported sustained symptom relief at final follow-up after a mean of 24 months (range 4-81). Mean ODS score did not change during the treatment. Patients with predominantly slow transit constipation or outlet obstruction did not differ concerning success rate.

CONCLUSIONS & INFERENCES

Sacral nerve stimulation has limited efficacy in unselected patients with chronic constipation and cannot be recommended for treatment on routine basis.

Towards a global system of vigilance and surveillance in unrelated donors of haematopoietic progenitor cells for transplantation

Safety of living donors is critical to the success of blood, tissue and organ transplantation. Structured and robust vigilance and surveillance systems exist as part of some national entities, but historically no global systems are in place to ensure conformity, harmonisation and the recognition of rare adverse events (AEs). The World Health Assembly has recently resolved to require AE/reaction (AE/R) reporting both nationally and globally. The World Marrow Donor Association (WMDA) is an international organisation promoting the safety of unrelated donors and progenitor cell products for use in haematopoietic progenitor cell (HPC) transplantation. To address this issue, we established a system for collecting, collating, analysing, distributing and reacting to serious adverse events and reactions (SAE/R) in unrelated HPC donors. The WMDA successfully instituted this reporting system with 203 SAE/R reported in 2011. The committee generated two rapid reports, reacting to specific SAE/R, resulting in practice changing policies. The system has a robust governance structure, formal feedback to the WMDA membership and transparent information flows to other agencies, specialist physicians and transplant programs and the general public.

Safety of formoterol in children and adolescents: experience from asthma clinical trials

BACKGROUND

The safety of long-acting β(2) agonist (LABA) therapy in asthma remains controversial but no large scale analyses have been published of LABA safety in children.

METHODS

The frequency of asthma-related deaths and hospitalisations following formoterol use in children (4-11 years) and adolescents (12-17 years), compared with non-LABA treatment, was assessed in all AstraZeneca-sponsored, randomised, controlled, parallel-group trials (≥3 months) where formoterol was used as maintenance and/or as reliever therapy.

RESULTS

11,849 children and adolescents under the age of 18 years from 41 trials were identified, 82% of whom used an inhaled corticosteroid (ICS) as concomitant medication. The number of asthma-related deaths (one 13-year-old boy among 7796 formoterol-treated patients, and none among 4053 non-LABA-treated patients) was too low to allow any between-group comparison. The frequency of patients with asthma-related hospitalisations was not different in formoterol-treated versus non-LABA-treated patients, either in children (1.16% (38/3263) vs 1.11% (24/2165)) or in adolescents (0.51% (23/4533) vs 0.85% (16/1888)). Asthma-related hospitalisations based on daily dose of formoterol were: (A) 4.5 or 9 µg: 1.9% (18/980); (B) 18 µg: 0.5% (14/2870); (C) 36 µg: 0% (0/67); and (D) variable dosing: 0.75% (29/3879). There was no difference between formoterol-treated and non-LABA-treated patients as regards ethnicity.

CONCLUSIONS

Formoterol use in children and adolescents (4-17 years) with asthma in this large study where the majority are prescribed concomitant ICS is not associated with any increased risk of asthma-related hospitalisations. The results are not influenced by dose or ethnicity.

Detection of cholangiocarcinoma with magnetic resonance spectroscopy of bile in patients with and without primary sclerosing cholangitis

BACKGROUND

Early detection of cholangiocarcinoma (CC) is very difficult, especially in patients with primary sclerosing cholangitis (PSC) who are at increased risk of developing CC.

PURPOSE

To evaluate 1H magnetic resonance spectroscopy ((1)H-MRS) of bile as a diagnostic marker for CC in patients with and without PSC.

MATERIAL AND METHODS

The institutional review board approved the study, and all patients gave informed consent. Bile from 49 patients was sampled and investigated using 1H-MRS. MR spectra of bile samples from 45 patients (18 female; age range 22-87 years, mean age 57 years) were analyzed both conventionally and using computerized multivariate analysis. Sixteen of the patients had CC, 18 had PSC, and 11 had other benign findings.

RESULTS

The spectra of bile from CC patients differed from the benign group in the levels of phosphatidylcholine, bile acids, lipid, and cholesterol. It was possible to distinguish CC from benign conditions in all patients with malignancy. Two benign non-PSC patients were misclassified as malignant. The sensitivity, specificity, and accuracy were 88.9%, 87.1%, and 87.8%, respectively.

CONCLUSION

With 1H-MRS of bile, cholangiocarcinoma could be discriminated from benign biliary conditions with or without PSC.

Epitope analysis of GAD65 binding in both cord blood and at the time of clinical diagnosis of childhood type 1 diabetes

The GAD65 epitope immunoglobulin binding pattern in cord blood of children (n=37), who later developed type 1 diabetes at 3.2-14.9 years of age, was analyzed. First, the binding at diagnosis was compared with that in the cord blood serum. The next comparison was between the cord blood serum and the mothers' serum taken at delivery. Basal GAD65 binding levels were determined in Protein A Sepharose-based radiobinding assays with (35)S-labeled human and rat GAD65, rat GAD67 and GAD65/67 fusion proteins representing N-terminal (N), middle (M) and C-terminal (C) epitopes. In the first comparison, 28/37 children had GAD65 binding above 2.44 relative units (RU) (upper three quartiles), representing a marked increase from birth in the binding to human GAD65 (p<0.0001), rat GAD65 (p<0.0001), N- (p=0.04), M- (p<0.0001), C- (p=0.001), and M + C-epitopes (p<0.0001), but not to rat GAD67. At birth, 9/37 had GAD65 binding above 1.56 RU (upper quartile) demonstrating that their binding of human (35)S-GAD65 was higher in cord blood than in the mother (p=0.008). Higher cord blood binding was also observed for the N- (p=0.02) terminal epitope but not for rat GAD65, rat GAD67, and the remaining epitopes. These data suggest that differences in the epitope GAD65 binding between mother and child at birth are limited. In contrast, the epitope pattern at diagnosis differed from that at birth, supporting the view that disease-associated epitopes develop between birth and diagnosis.

Diagnostic and prognostic implications of DNA ploidy and S-phase evaluation in the assessment of malignancy in biliary strictures

BACKGROUND AND STUDY AIMS

Brush cytology of biliary strictures has a low sensitivity for diagnosing malignancy, and additional diagnostic tools are needed. The aim of the present study was to assess the diagnostic and prognostic importance of DNA measurements as an adjunct to brush cytology in patients with biliary strictures.

PATIENTS AND METHODS

All patients (n = 225) with bile duct strictures who underwent endoscopic retrograde cholangiopancreatography (ERCP) between January 1997 and October 2003 at the Department of Radiology at Karolinska University Hospital, Huddinge, Sweden, were included in the study. While 66 patients had an unclear final diagnosis and were therefore excluded, the remaining 159 patients were assessed with brush cytology and DNA flow cytometry.

RESULTS

Sensitivity and specificity of DNA aneuploidy for tumor detection were 43 % and 96 %. Using DNA analysis in addition to brush cytology, the sensitivity was 62 % compared with 57 % for brush cytology alone (not significant). Patients with diploid DNA tumors had a significantly better survival than patients with aneuploid DNA tumors ( P = 0.02). The mean survival was 10 months for diploid cancers and 6 months for aneuploid cancers.

CONCLUSION

DNA ploidy measurement may be a diagnostic method that could supplement brush cytology in the identification of malignancy in biliary strictures. DNA aneuploidy is a marker of poor prognosis in patients with malignant biliary strictures.

Effects of Three Months of Low Molecular Weight Heparin (dalteparin) Treatment After Bypass Surgery for Lower Limb Ischemia—A Randomised Placebo-controlled Double Blind Multicentre Trial

OBJECTIVES

To test the hypothesis that long-term postoperative dalteparin (Fragmin), Pharmacia Corp) treatment improves primary patency of peripheral arterial bypass grafts (PABG) in lower limb ischemia patients on acetylsalicylic acid (ASA) treatment.

DESIGN

Prospective randomised double blind multicenter study.

MATERIALS AND METHODS

Using a computer algorithm 284 patients with lower limb ischemia, most with pre-operative ischemic ulceration or partial gangrene, from 12 hospitals were randomised, after PABG, to 5000 IU dalteparin or placebo injections once daily for 3 months. All patients received 75 mg of ASA daily for 12 months. Graft patency was assessed at 1, 3 and 12 months.

RESULTS

At 1 year, 42 patients had died or were lost to follow-up. Compliance with the injection schedule was 80%. Primary patency rate, in the dalteparin versus the control group, respectively, was 83 versus 80% (n.s.) at 3 months and 59% for both groups at 12 months. Major complication rates and cardiovascular morbidity were not different between the two groups.

CONCLUSIONS

In patients on ASA treatment, long-term postoperative dalteparin treatment did not improve patency after peripheral artery bypass grafting. Therefore, low molecular weight heparin treatment cannot be recommended for routine use after bypass surgery for critical lower limb ischemia.

Intraoperative endoscopic retrograde cholangiopancreatography (ERCP) to remove common bile duct stones during routine laparoscopic cholecystectomy does not prolong hospitalization: a 2-year experience

BACKGROUND

There is still some controversy regarding the optimal timing and best method for the removal of common bile duct stones (CBDS). Intraoperative endoscopic retrograde cholangiopancreaticography (IO-ERCP) is an alternative method that should be considered for this procedure. The aim of our study was to investigate the clinical outcome of a single-step procedure (IO-ERCP) to remove CBDS, thereby combining two existing high-volume clinical modalities-i.e., laparoscopic cholecystectomy (LC) and ERCP.

METHODS

Between January 2000 and December 2001, 674 patients, 192 male and 482 female, underwent cholecystectomy at our hospital. There were 612 LC (90.8%), 37 converted procedures (5.5%), and 25 open operations (3.7%). In 592 of the patients, (87.8%) intraoperative cholangiography (IOC) was performed. In 34 (5.7%) of those who had and IOC, an IO-ERCP was performed. While the surgeon waited for the endoscopist, care was taken to introduce a thin guidewire through the lOC catheter and pass it through the sphincter of Oddi, out into the duodenum. This complementary procedure greatly facilitated the subsequent cannulation of the bile ducts.

RESULTS

The cannulation frequency of the CBD was 100%. Common bile duct stones were successfully extracted in 93.5%. Endoscopic sphincterotomy (EST), followed by the insertion of a plastic endoprosthesis, was performed in two patients with remaining stones. The CBD of these two patients was cleared by postoperative ERCP. None of the patients developed postoperative pancreatitis. The operating time was prolonged as compared with the time for LC (192 vs 110 mins; p < 0.05). The length of hospitalization for IO-ERCP patients did not differ from that for patients undergoing cholecystectomy alone (2.6 vs 2.1. days; NS).

CONCLUSIONS

The study suggests that elective IO-ERCP is a safe and efficient method for removing CBDS that has a low risk of inducing postoperative pancreatitis and does not prolong postoperative hospitalization. This technique enables perioperative extraction of CBDS without open or laparoscopic surgical exploration of the CBD and can be used safely in a routine clinical setting.

Diagnosis of biliary strictures in conjunction with endoscopic retrograde cholangiopancreaticography, with special reference to patients with primary sclerosing cholangitis

BACKGROUND AND STUDY AIMS

Strictures of the bile ducts due to malignant changes are difficult to distinguish from benign changes, particularly in patients with primary sclerosing cholangitis (PSC). The aim of this study was to evaluate diagnostic methods for malignancy in biliary strictures in conjunction with endoscopic retrograde cholangiopancreaticography (ERCP).

PATIENTS AND METHODS

Bile duct strictures were identified during ERCP in 57 patients, who were thus included in the present study. Brush samples from the strictures were taken for cytology and for evaluation of DNA content by flow cytometry. The tumor markers CA 19-9 and CEA were determined both in serum and bile fluid. Two independent radiologists evaluated all cholangiograms. The diagnostic sensitivity, specificity, and accuracy of each diagnostic method were evaluated separately and in combination.

RESULTS

32 patients were found to have malignant strictures and when the four methods: brush cytology, DNA analysis, serum CA 19-9 and serum CEA were combined, a diagnostic sensitivity of 88 % and specificity of 80 % were reached. Seven of the 20 patients with PSC were found also to suffer from cholangiocarcinoma, yielding a sensitivity and specificity of 100 % and 85 %, respectively. Analyses of CA 19-9 and CEA in bile fluid had no diagnostic significance.

CONCLUSION

An ERCP procedure with brush cytology, a DNA analysis, combined with serum analysis of CA 19-9 and CEA, can increase the possibility of distinguishing between malignant and benign biliary strictures, especially in PSC patients.

E2F repression by C/EBPalpha is required for adipogenesis and granulopoiesis in vivo

The C/EBPalpha transcription factor is required for differentiation of adipocytes and neutrophil granulocytes, and controls cellular proliferation in vivo. To address the molecular mechanisms of C/EBPalpha action, we have identified C/EBPalpha mutants defective in repression of E2F-dependent transcription and found them to be impaired in their ability to suppress cellular proliferation, and to induce adipocyte differentiation in vitro. Using targeted mutagenesis of the mouse germline, we show that E2F repression-deficient C/EBPalpha alleles failed to support adipocyte and granulocyte differentiation in vivo. These results indicate that E2F repression by C/EBPalpha is critical for its ability to induce terminal differentiation, and thus provide genetic evidence that direct cell cycle control by a mammalian lineage-instructive transcription factor couples cellular growth arrest and differentiation.

Prospective evaluation of hot flashes during treatment with parenteral estrogen or complete androgen ablation for metastatic carcinoma of the prostate

PURPOSE

We evaluated the incidence and frequency of, and distress due to hot flashes after castration therapy with polyestradiol phosphate and complete androgen ablation.

MATERIALS AND METHODS

A total of 915 men with metastatic prostate carcinoma enrolled in the Scandinavian Prostatic Cancer Group-5 trial study were randomized to intramuscular injections of 240 mg. Polyestradiol phosphate every 2 weeks for 8 weeks followed by monthly subcutaneous injections or complete androgen ablation, that is bilateral orchiectomy or 3.75 mg. of the gonadotropin-releasing hormone analog triptorelin monthly combined with 250 mg. of the antiandrogen flutamide 3 times daily. The incidence and frequency of, and distress due to hot flashes were recorded at regular intervals using a questionnaire.

RESULTS

Of the 915 men 901 were evaluated at a median followup of 18.5 months. The incidence of hot flashes was 30.1% and 74.3% in the polyestradiol phosphate and complete androgen ablation groups, respectively (p <0.001). In the polyestradiol phosphate group the frequency of and distress due to hot flashes were significantly lower than in the androgen ablation group. There was complete relief from hot flashes in 50% of the men on polyestradiol phosphate during followup compared with none on androgen ablation. The incidence of hot flashes did not differ in men with and without tumor progression.

CONCLUSIONS

Endocrine treatment with polyestradiol phosphate induced fewer and less distressing hot flashes than complete androgen ablation. Flashes also disappeared to a greater extent during polyestradiol phosphate than during androgen ablation. The data in this study enable us to provide thorough individual information to patients on the risk and grade of expected distress and duration of hot flashes during polyestradiol phosphate or complete androgen ablation treatment.

Prediction of silent celiac disease at diagnosis of childhood type 1 diabetes by tissue transglutaminase autoantibodies and HLA

AIMS

The aims were to estimate the diagnostic sensitivity and specificity of autoantibodies to tissue transglutaminase (IgA- and IgG-tTG), gliadin (AGA) and endomysium (EMA) in relation to human leukocyte antigen (HLA)-DQB1 alleles to identify silent celiac disease at diagnosis of type 1 diabetes.

METHODS

IgA- and IgG-tTG were measured in radioligand binding assays in 165 type 1 diabetic patients. Data on HLA-DQB1 were available for 148 patients and on both AGA and EMA for 164 patients. For patients considered positive for AGA or EMA, or both, an intestinal biopsy was suggested. HLA-DQB1 typing was carried out by polymerase chain reaction and hybridization with allele specific probes.

RESULTS

Three patients, left out from further study of antibodies, but not from HLA-DQB1 analysis, had treated celiac disease at diagnosis. Out of the other 162 type 1 diabetic patients tested, nine had IgA-tTG, six IgG-tTG, eight EMA, and 11 AGA. Biopsy was suggested for nine patients, of whom six showed villous atrophy, one did not and two refused to participate. Thus, silent celiac disease was probable in 8/162 and biopsy-verified in 6/162, where five patients were AGA-positive and six either EMA-, IgA-tTG- or IgG-tTG-positive. Of the 11 patients with celiac disease (three with treated and eight with silent celiac disease), 10 were HLA-DQB1-typed, of whom 65% (13/20) had the DQB1*02 allele, compared with 36% (100/276; p = 0.011) of those without celiac disease. IgA-tTG levels were higher in patients having either *02 or *0302 (0.6; -1.3-112.4 RU) compared with those not having these alleles (0.4; -0.7-3.4 RU; p = 0.023).

CONCLUSION

IgA-tTG are HLA-DQB1*02-associated autoantibodies with high sensitivity and specificity for silent celiac disease at diagnosis of type 1 diabetes.

Comparison of some different methods for analysis of thyroid autoantibodies: importance of thyroglobulin autoantibodies

Blood samples from 141 children and adolescents were used to evaluate differences between commercial kits and radioimmunoassay (RIA) methods for detecting thyroid autoantibodies. Thyroglobulin autoantibodies (Tg-Ab) were analyzed with a hemagglutination kit and a RIA; thyroid peroxidase autoantibodies (TPO-Ab) were measured with a gelagglutination assay and a RIA. The results of the antibody tests were compared with thyroid function tests (triiodothyronine [T3], thyroxine [T4], thyrotropin [TSH]) and with the results of ultrasound of the thyroid in antibody-positive patients. The correlation of antibody levels between the two methods was higher for TPO-Ab than for Tg-Ab. Moderate to high levels of TPO-Ab correlated to elevated TSH levels. Autoimmune thyroiditis (AIT) was found in 6 of the 141 children. The RIA-based thyroglobulin assay was the only test that identified autoantibodies in all 6 cases. In contrast, the hemagglutination kit thyroglobulin assay failed to identify 4 of the 6 AIT cases.

Intervention models on psycho-social health in families with an asthmatic child

Despite an increase in the prevalence of asthma during the last few decades, the need for hospital treatment of children with asthma has become less. One reason for this is that children and their parents are now more involved in the treatment of the disease, and responsibility has been shifted from the medical care system to the family. This new responsibility may cause increased psycho-social tension within the family. We conducted a pilot study on three limited methods of intervention to find the best way to help families in this respect. All three methods (individual family meetings, family group meetings, and evaluation of the child's environment in school) reduced the psychosocial burden of having a child with asthma. This indicates that families should be supported by being given the opportunity to participate in meetings to discuss the disease or to have the environment in the child's school evaluated, in addition to receiving regular medical care.

Prevalence of beta-cell and thyroid autoantibody positivity in schoolchildren during three-year follow-up

The prevalence of autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GAD65Ab), insulin (IAA), islet cells (ICA), thyroid peroxidase (TPOAb) and thyroglobulin (TgAb), in relation to HLA-DR types, was assessed in 310 (HLA in 280) twelve-year-old children during three-year follow-up. Altogether, 26.8% (83/310) of the children were found to carry at least one autoantibody. The HLA-DR3/DR4 genotype was significantly more prevalent in the subgroup of children GAD65Ab-positive on at least one occasion than among GAD65Ab-negative children [33% (2/6) vs. 5% (12/274); p = 0.031, as was the HLA-DR4/x genotype among children seropositive for at least one thyroid autoantibody, compared to the corresponding seronegative subgroup 152% (34/65) vs. 34% (74/215); p=0.01]. The proportion of children seropositive in at least one of the three tests was 1.9% (6/310) for GAD65Ab, 2.6% (8/310) for IAA, 5.2% (16/310) for ICA, 11.3% (35/310) for TPOAb and 19.4% (60/310) for TgAb. All autoantibodies except GAD65Ab tended to disappear during follow-up, and at the three-year follow-up IAA had disappeared in 50% (2/4) of cases, ICA in 67% (6/9), TPOAb in 30% (6/20) and TgAb in 38% (18/47) of cases. The turnover of seropositive subjects and the large proportion of children seropositive for at least one islet or thyroid autoantibody during a three-year follow-up suggest transient autoantibodies to be more common than is discernible in cross-sectional investigations.

Previous exposure to measles, mumps, and rubella--but not vaccination during adolescence--correlates to the prevalence of pancreatic and thyroid autoantibodies

OBJECTIVE

This study was designed to determine whether a relationship exists between previous exposure to measles, mumps, and rubella (MMR) by natural infection or vaccination or by new immunization with MMR vaccine, and either the presence or levels of autoantibodies against thyroid cell and pancreatic beta-cell antigens.

METHODS

Antibodies against MMR and autoantibodies against thyroglobulin, thyroid peroxidase, pancreas islet cells (ICA), islet cell surface, glutamic acid decarboxylase 65k autoantibodies, and insulin were studied before, and 3 months after, vaccination with combined MMR vaccine in 386 school children between 11 and 13 years of age.

RESULTS

The vaccination changed neither the prevalence nor the level of autoantibodies. Children with rubella antibodies before vaccination had higher levels of ICA than did the rubella seronegative children. In contrast, thyroid autoantibody levels and prevalence were lower in children with antibodies against measles, mumps, or both before vaccination than in children without those antibodies.

CONCLUSIONS

Previous natural infection or vaccination against measles, mumps, or both seemed to have an inhibitory effect on the development of thyroid autoantibodies. In contrast, children with previous exposure to rubella had higher levels of ICA. No evidence was found that MMR vaccination during adolescence may trigger autoimmunity.

The microbiota of periodontal pockets with different depths in therapy-resistant periodontitis

This study presents the composition of the cultivable microbiota colonising periodontal pockets of different depths among 2 patient-groups classified as non-responsive (NR-group; 11 participants) or responsive (R-group; 10 participants) to periodontal treatment. Microbiological samples from three types of pocket (< 4 mm deep A-samples; 4-5 mm B-samples; > 5 mm C-samples) were analysed by cultural methods for putative periodontitis pathogens, microbial groups constituting > or = 5% of the total cultivable flora and opportunistic pathogens. Actinomyces naeslundii, A. israelii, Bacteroides forsythus, Fusobacterium spp, Porphyromonas gingivalis, Prevotella intermedia, Peptostreptococcus micros, anaerobic streptococci and facultative anaerobic streptococci were most prevalent. Actinobacillus actinomycetemcomitans, Staphylococcus aureus, enteric rods and yeasts were less prevalent. The periodontitis pathogens Bacteroides forsythus, Fusobacterium spp, Porphyromonas gingivalis, Prevotella intermedia and Peptostreptococcus micros constituted together (on average) < or = 23% of the viable counts in the A- and B-samples of both patient groups and in the C-samples of the R-group. In the C-samples of the NR-group their mean counts were 45%. Correlations were found between smoking habits and the five pathogens in the C-samples and in pooled pocket depth samples. The results show that groups of periodontopathogens should be considered a causal factor in therapy-resistant periodontitis. Further, smoking and deep pockets can enhance a shift in the balance of the subgingival microflora predisposing a site to disease and a susceptible host may be the pre-requisite to therapy-resistant periodontitis.

Islet autoantibodies in cord blood from children who developed type I (insulin-dependent) diabetes mellitus before 15 years of age

Islet autoantibodies are early markers for Type I (insulin-dependent) diabetes mellitus. The aim of this study was to establish whether islet autoantibodies were present at birth in children who developed Type I diabetes before 15 years of age. Cord blood sera from 81 children who developed Type I diabetes between 10 months and 14.9 years of age were tested for glutamic acid decarboxylase autoantibodies (GAD65Ab), islet cell antigen 512 autoantibodies (ICA512Ab), insulin autoantibodies (IAA) all by quantitative radioligand binding assays and islet cell autoantibodies (ICA) by indirect immunofluorescence. Cord blood sera from 320 randomly selected matched children were controls. The children who developed Type I diabetes had an increased frequency of cord blood islet autoantibodies compared with control subjects: Glutamic acid decarboxylase autoantibodies were detected in 6% (5/81) patients and 2% (5/320) control subjects (p = 0.03); islet cell antigen 512 autoantibodies in 5% (4/73) patients and 1% (4/288) control subjects (p = 0.06); insulin autoantibodies (IAA) in 0% (0/79) patients and 0.3% (1/320) control subjects (p = 0.36); and islet cell autoantibodies in 10% (8/81) patients compared with 0.6% (2/320) control subjects (p = 0.0001). Taken together, 17% (14/81) patients had one or more islet autoantibody compared with 4% (12/320) control subjects (p = 0.0001). Whereas none of the control children had more than one antibody, 4% (3/81) children who later developed Type I diabetes were double positive (p = 0.002). Although glutamic acid decarboxylase autoantibodies' concentrations in cord-blood correlated to those in the mothers' blood at the time of delivery, no corresponding correlation was found for the other two types of autoantibodies. The increased frequency of cord blood islet autoantibodies suggests that the Type I diabetes process could already be initiated in utero.

Glutamate decarboxylase antibodies in non-diabetic pregnancy precedes insulin-dependent diabetes in the mother but not necessarily in the offspring

We studied the risk for diabetes of glutamate decarboxylase (GAD65Ab) and islet cell (ICA) autoantibodies in non-diabetic pregnant mothers and their children. Pregnancy and cord blood sera were collected in 1970-87 from about 35,000 mothers who delivered a child in the city of Malmö, Sweden. A total of 42 mothers were identified in 1988 who, 1-18 years after their pregnancies, had developed either insulin-dependent (n = 22) or non-insulin dependent (n = 20) diabetes mellitus. First, in 123 pregnant mothers selected as controls, 0.8% had GAD65Ab and 0.8% ICA. Second, among the mothers with non-insulin dependent diabetes, 7/20 (35%) had GAD65Ab eight months to 13 years, 10 months before clinical diagnosis. Third, in mothers who later developed insulin-dependent diabetes, 12/22 (55%) had GAD65Ab and 10/22 (45%) had ICA in pregnancies preceding the clinical diagnosis by 13 months to 9 years, 4 months. In 1996, none of the children born to the 42 mothers have developed diabetes. GAD65Ab and ICA in non-diabetic pregnancies may predict insulin-dependent diabetes in the mother but not necessarily in the offspring.

Bolus injection (2-4 min) versus short-term (10-20 min) infusion of 5-fluorouracil in patients with advanced colorectal cancer: a prospective randomised trial. Nordic Gastrointestinal Tumour Adjuvant Therapy Group

The use of bolus 5-fluorouracil (5-FU) as a short-term infusion over 10-30 min is increasing at the cost of a push injection, mainly due to practical advantages. Since even a short prolongation of the administration time results in lower 5-FU peak and area under the curve (AUC) levels, there might be a risk of decreased efficacy. The aim of this study was to compare a rapid intravenous (i.v.) 5-FU injection and a short-term 5-FU infusion with respect to objective responses and toxicity in patients with advanced colorectal cancer. 203 patients with measurable advanced colorectal cancer were randomised to bolus 5-FU either as an injection for 2-4 min or as a short-term infusion lasting 10-20 min. In both groups, the 5-FU dose was 500 mg/m2 and leucovorin 60 mg/m2 was given 40 min after the start of 5-FU. Treatment was given on two successive days every other week until progression. Objective tumour regression was seen in 27/100 (27%) in the injection group and in 13/103 (13%) in the infusion group (P = 0.02). Severe toxicity was rare and did not differ significantly between the groups. Progression-free survival tended to be longer in the injection group (P = 0.07), but overall survival did not differ between the groups. Bolus 5-FU should be administered as a rapid i.v. injection rather than as a short-term infusion, since the former rate of administration results in a higher response rate without being significantly more toxic.

The coexistence of thyroid autoimmunity in children and adolescents with various allergic diseases

The aim of our study was to investigate the coexistence of thyroid autoimmunity and allergic diseases. The prevalence of thyroid autoantibodies was studied in sera from 140 children with different kinds of allergic diseases, 370 11-13-y-old schoolchildren without allergic diseases serving as controls. The prevalence of thyroid peroxidase autoantibodies was found to be higher among the patients than in the control group, 11.4% vs 5.4% (p < 0.05). Ultrasound investigation identified autoimmune thyroiditis in 4.3% (6/140) of the series, which was later confirmed with fine needle aspiration in all six cases, four of which were unknown prior to the study. Our findings may be useful to alert clinicians that thyroid diseases may be superimposed on allergic children.

Prevalence of IgA-antigliadin antibodies and IgA-antiendomysium antibodies related to celiac disease in children with Down syndrome

OBJECTIVE

This study was undertaken to investigate the prevalence of celiac disease in children and adolescents with Down syndrome.

MATERIAL AND METHODS

Forty-three children and adolescents with Down syndrome were screened for IgA-antigliadin antibodies (AGA) and IgA-antiendomysium antibodies (EMA). Patients found to be either AGA- or EMA-positive were investigated further with intestinal biopsy.

RESULTS

None of the 43 patients had known celiac disease at entry into the study; 37% (16/43) were found to have AGA levels above normal, and 16% (7/43) to be EMA-positive. Of the 15 patients who underwent biopsy, 8 manifested villous atrophy. Villous atrophy was present in all 7 of the EMA-positive patients, whereas the villi were normal in 7 of the 13 AGA-positive patients who underwent biopsy.

CONCLUSIONS

EMA is a good immunologic marker for use in screening for celiac disease, and screening is justified in patients with Down syndrome.

Intravenous nitroglycerin for rapid uterine relaxation

BACKGROUND

To investigate the effect of nitroglycerin in vitro and in vivo on human uterine contractile activity.

METHODS

In vitro myometrial strips were obtained from six pregnant women at term who underwent elective cesarean section. The biopsies were mounted in tissue baths. After spontaneous or oxytocin-induced activity had been accomplished, nitroglycerin in various concentrations was added to the baths and the effects were continuously registered. In vivo, in an open study nitroglycerin was administered as a bolus injection of 100-200 micrograms intravenously to 32 women at cesarean section when uterine relaxation was urgently needed; to 22 other women after vaginal delivery for facilitation of manual removal of retained placentas, and to one patient at vaginal delivery of premature twins.

RESULTS

In vitro nitroglycerin induced a dose-dependent inhibition of spontaneous as well as oxytocin-induced myometrial contractile activity. Complete muscular relaxation was obtained at a concentration of 25-50 micrograms/ml. In vivo all patients had rapid effective uterine relaxation after intravenous injection of 100-200 micrograms nitroglycerin.

CONCLUSION

Nitroglycerin administered intravenously seems to be a rapid and effective uterine muscle relaxant agent without overt adverse effects on mother or fetus.

High prevalence of thyroid autoantibodies at diagnosis of insulin-dependent diabetes mellitus in Swedish children

The prevalence of thyroglobulin autoantibodies and that of thyroid peroxidase autoantibodies were studied in serum samples from 52 children with insulin-dependent diabetes mellitus, sampled at diagnosis and before the start of insulin treatment, with 386 non-diabetic schoolchildren (11 to 13 years of age) serving as control subjects. Using exactly the same sensitive solid-phase immunosorbent radioassay for both thyroid autoantibodies, with comparable sensitivity, we found the prevalences of both autoantibodies to be higher in the insulin-dependent diabetes mellitus group than in the control group, the difference being most pronounced for thyroid peroxidase autoantibodies. Thyroglobulin autoantibodies were positive in 33% of the diabetics versus 14% in the control group (p = 0.002), and thyroid peroxidase autoantibodies were positive in 38% versus 6% (p = 0.0001). The high prevalence of thyroid autoantibodies already at diagnosis stresses the importance of early screening for thyroid disease in patients with insulin-dependent diabetes mellitus.

[Potentially avoidable perinatal deaths in Denmark and Sweden 1991]

In 1991 the perinatal mortality rate in Denmark was 8.0/1000 deliveries compared to 6.5/1000 in Sweden. An international audit was designed to investigate whether the perinatal death rates in the two countries to some extent could reflect differences in the quality of care. Medical records of 97% of all perinatal deaths in 1991 in the two countries were analyzed. A new classification focusing on potential avoidability from a health services perspective was elaborated at a Nordic-Baltic workshop, using the variables: time of death in relation to admission and delivery, fetal malformation, gestational age, growth-retardation and Apgar score at 5 min. Rates of perinatal deaths of malformed infants (0.00195 and 0.00145) and intrapartum deaths of non-malformed infants (0.00042 and 0.00019) were significantly higher in Denmark than in Sweden. The study raised the following questions: why is the rate of perinatal death of malformed infants higher in Denmark than in Sweden and could intrapartum care in Denmark be improved?

Twenty years' colonoscopic surveillance of patients with ulcerative colitis. Detection of dysplastic and malignant transformation

BACKGROUND

Endoscopic cancer surveillance in patients with ulcerative colitis has been performed for almost 3 decades. There is still no consensus on its clinical value.

METHODS

This study evaluates a 20-year prospective study of 143 patients with extensive ulcerative colitis and a disease duration exceeding 10 years. Colonoscopy with double biopsy specimens from nine locations of the colon was performed every 2nd year. Biopsy specimens showing dysplasia were reviewed at the end of the study.

RESULTS

Through the surveillance dysplasia/cancer was detected in 55 patients; 7 of these patients had carcinomas, and 2 were in a possibly curable stage (Dukes A). The predictive value of low-grade dysplasia for either high-grade dysplasia or cancer was 41%.

CONCLUSIONS

Although impaired by limiting factors, colonoscopic surveillance of chronic extensive colitis may identify patients with dysplasia and thereby prevent malignant transformation.

Potentially avoidable perinatal deaths in Denmark and Sweden 1991

BACKGROUND

Since 1950 the perinatal mortality has been significantly higher in Denmark than in Sweden. In 1991 the rate in Denmark was 8.0/1000 deliveries compared to 6.5/1000 in Sweden. An international audit was designed to investigate whether the perinatal death rates in the two countries to some extent could reflect differences in the quality of care, indicated by the numbers of perinatal deaths in categories of potentially avoidable deaths.

MATERIAL AND METHODS

Medical records of 97% of all perinatal deaths in 1991 in the two countries were analyzed. A new classification focusing on potential avoidability from a health services perspective was elaborated at a Nordic-Baltic workshop, using the variables: time of death in relation to admission and delivery, fetal malformation, gestational age, growth-retardation and Apgar score at 5 min.

RESULTS

Rates of perinatal deaths of malformed infants (0.00195 and 0.00145) and intrapartum deaths of non-malformed infants (0.00042 and 0.00019) was significantly higher in Denmark than in Sweden.

CONCLUSION

Application of the Nordic-Baltic Perinatal Death Classification on perinatal deaths in Denmark and Sweden in 1991 raises the questions as to why the rate of perinatal death of malformed infants is higher in Denmark than in Sweden and whether intrapartum care in Denmark could be improved.

Separation of cyclodextrins and their derivatives by thin-layer and preparative column chromatography

Cyclodextrins, their derivatives and products of their partial hydrolysis are clearly separated by chromatography on silica gel by mobile phases containing aqueous ammonia and organic solvent (acetonitrile or 1-propanol). This system allows separation of compounds with different numbers of substituents on cyclodextrin, but does not allow the separation of isomers; the system can be used both for thin-layer chromatography and for preparative column chromatography. The isomers in the fraction thus obtained can be in some cases separated, after peracetylation, by chromatography on silica gel using a mobile phase consisting of methanol and dichloromethane. This chromatographic sequence potentially yields derivatives of cyclodextrins in quantities which enable evaluation of their solubilization and biological properties.

Calcium channel blockade (isradipine) in treatment of hypertension in pregnancy: a randomized placebo-controlled study

OBJECTIVE

Our purpose was to study the effects of isradipine, a dihydropyridine calcium channel blocker, on mother and fetus in the treatment of hypertensive disorders of pregnancy.

STUDY DESIGN

The investigation was performed as a two-group, parallel, double-blind multicenter study of isradipine versus placebo. Fifty-four women were randomized to treatment with isradipine slow-release capsules given orally 5 mg twice a day and 57 to a placebo group.

RESULTS

Isradipine lowered the maternal mean arterial blood pressure effectively in women with nonproteinuric hypertension but did not do so in women with proteinuria at recruitment or appearing during treatment. Blood flow in the umbilical artery and maternal renal and liver function were not influenced by treatment. Isradipine had few side effects and was well tolerated.

CONCLUSION

Calcium channel blockade with isradipine is effective for treatment of nonproteinuric hypertension but not in preeclampsia.

The use of intravenous nitroglycerin for emergency cervico-uterine relaxation

A patient with a twin pregnancy was in preterm labour after 25 gestational weeks when, during vaginal delivery of the second twin, severe spasm of the cervix and fetal bradycardia ensued. Induction of general anesthesia did not relax the cervix. After bolus doses of nitroglycerin 100 + 50 micrograms i.v., prompt cervico-uterine relaxation was obtained allowing manual extraction of the baby. A short review of the literature and a summary of our experience in the administration of nitroglycerin i.v. in obstetrics are presented.

Maternal enteroviral infection during pregnancy as a risk factor for childhood IDDM. A population-based case-control study

Using the nationwide childhood-onset diabetes register in Sweden, we were able to trace children who contracted diabetes before the age of 15 years and who were born at a specific hospital in Sweden where maternal sera from delivery had been stored during the years 1969-1989. Sera obtained at delivery from 57 mothers of diabetic children were compared with sera from 203 mothers of control subjects who were delivered at the same hospital during the same time period. The sera were analyzed blindly using a group-specific enzyme-linked immunosorbent assay for enteroviral IgG and IgM antibodies before and after urea wash as an avidity test. On the same plates, IgG antibodies to herpes, mumps, and toxoplasmosis were analyzed. The mean absorbance values of enteroviral IgG antibodies against enteroviral antigens (echo30, coxsackie B5, and echo9) were significantly higher among mothers whose children later developed diabetes (P = 0.002, P = 0.02, and P = 0.04, respectively). When reduction in activity after urea wash, indicating recently formed antibodies, was compared, the differences were even more pronounced (P < 0.001 for all three antigens). No significant differences were found for antibodies against herpes (all types), herpes type 2, mumps, or toxoplasmosis. When IgM activity and/or a significant decrease in avidity index, an indication of recent enterovirus infection, was used as a risk exposure, the odds ratio standardized for year of birth (95% confidence interval) was 3.19 (1.39-7.30). We conclude that the results of this study indicate that enteroviral infection during pregnancy is a risk factor for childhood-onset diabetes in the offspring.(ABSTRACT TRUNCATED AT 250 WORDS)

The reaction between epichlorohydrin and polysaccharides: Part 2, Synthesis of some model substances, with cyclic substituents

Eight derivatives of methyl alpha-D-glucopyranoside, in which the substituents are part of cyclic structures, have been prepared as model substances for possible structural elements formed on reaction of polysaccharides with epichlorohydrin. The substances were converted into the permethylated alditol-1-d acetates and characterised by CIMS and EIMS.

Regioselectivity of alkylation of cyclomaltoheptaose (beta-cyclodextrin) and synthesis of its mono-2-O-methyl, -ethyl, -allyl, and -propyl derivatives

Mono-2-O-methyl-, -2-O-ethyl-, and -2-O-allyl-cyclomaltoheptaose were prepared by alkylations of cyclomaltoheptaose in dilute aqueous alkali, and mono-2-O-propylcyclomaltoheptaose was obtained by hydrogenation of the allyl derivative. All the 2-O-alkyl derivatives were less soluble in water than was cyclomaltoheptaose. All formed inclusion complexes with toluene in aqueous solution, but only the methyl ether was less soluble in the water-toluene system than in water. The solubilities of the other ethers in water were enhanced by the addition of toluene. Partial methylation of cyclomaltoheptase with 13C-enriched dimethyl sulfate in dilute aqueous alkali yielded mixtures of products. The substitution patterns were analyzed by GLC-MS of the alditol acetates, prepared by hydrolysis, reduction, and acetylation, and by 13C NMR after complete permethylation with nonenriched reagent. The results showed that methylation at O-2 is a predominant but not an exclusive reaction; as expected, the regioselectivity decreases with increasing degree of methylation.

Structural studies of the Shigella boydii type 5 O-antigen polysaccharide

The structure of the Shigella boydii type 5 O-antigen polysaccharide has been investigated by sugar and methylation analyses, and specific degradations. It is proposed that it is composed of hexasaccharide repeating units with the following structure. The repeating unit also contains an O-acetyl group, linked to one of the primary positions. [formula: see text]

The reaction between epichlorohydrin and polysaccharides: Part 1. Syntheses of some model substances with non-cyclic substituents

Five derivatives of methyl alpha-D-glucopyranoside, in which the substituents form noncyclic structures, have been prepared as model substances for possible structural elements formed on reaction of polysaccharides with epichlorohydrin. The substances were converted into the permethylated alditol-1-d derivatives and characterised by CIMS and EIMS.

Structural studies of the capsular polysaccharide from Klebsiella type 38: a reinvestigation

The structure of the capsular polysaccharide from Klebsiella type K38 has been reinvestigated. It is composed of pentasaccharide repeating units of the structure given below. In this structure, Sug stands for a 4-deoxy-threo-hex-4-enopyranosyluronic acid group, most probably having the beta-L configuration. 1H NMR studies further indicate that this group assumes the 1H2 conformation. [formula: see text]