RNA sequencing of intestinal mucosa reveals novel pathways functionally linked to celiac disease pathogenesis

BACKGROUND & AIMS

The early steps in the pathophysiology of celiac disease (CD) leading to loss of tolerance to gluten are poorly described. Our aim was to use RNA sequencing of duodenal biopsies in patients with active CD, CD in remission, and non-CD controls to gain insight into CD pathophysiology, identify additional genetic signatures linked to CD, and possibly uncover targets for future therapeutic agents.

METHODS

We performed whole transcriptome shotgun sequencing of intestinal biopsies in subjects with active and remission CD and non-CD controls. We also performed functional pathway analysis of differentially expressed genes to identify statistically significant pathways that are up or down regulated in subjects with active CD compared to remission CD.

RESULTS

We identified the upregulation of novel genes including IL12R, ITGAM and IGSF4 involved in the immune response machinery and cell adhesion process in the mucosa of subjects with active CD compared to those in remission. We identified a unique signature of genes, related to innate immunity, perturbed exclusively in CD irrespective of disease status. Finally, we highlight novel pathways of interest that may contribute to the early steps of CD pathogenesis and its comorbidities such as the spliceosome, pathways related to the innate immune response, and pathways related to autoimmunity.

CONCLUSIONS

Our study confirmed previous findings based on GWAS and immunological studies pertinent to CD pathogenesis and describes novel genes and pathways that with further validation may be found to contribute to the early steps in the pathogenesis of CD, ongoing inflammation, and comorbidities associated with CD.

Targeted genotyping for the prediction of celiac disease autoimmunity development in patients with type 1 diabetes and their family members

BACKGROUND

Patients with type 1 diabetes (T1D) and their first-degree relatives (FDRs) have an increased risk of developing celiac disease (CD) compared to the general population. This is largely explained by the shared association with major histocompatibility class II human leukocyte antigen (HLA) DQ2 and/or DQ8 between the two disease states.

AIM

To describe the frequency of CD autoimmunity (CDA) and the distribution of HLA and haptoglobin genotypes in patients with T1D and their FDRs. Additionally, we aimed at identifying predictors associated with an increased risk of developing CDA in patients with T1D and their family members.

METHODS

We obtained clinical information and blood samples from 1027 participants (302 with T1D and 725 FDRs) over a five-year period. Samples were tested for autoantibodies associated with CD, HLA-DQ alleles, and haptoglobin genotype. We fit univariate and multiple logistic regression models for CDA separately for subjects with T1D and for FDRs of subjects with T1D.

RESULTS

Implementation of a screening program increased the frequency of CDA by 2-fold in participants with T1D and 2.8-fold in their FDRs. Multivariate analysis found that, in participants with T1D, having both DR7-DQ2 and DR4-DQ8 was associated with an increased frequency of CDA. In FDRs of T1D patients, reported CD in the family was associated with an increased frequency of CDA during screening. Haptoglobin 2 genotype was not associated with developing CDA in the multivariate analysis.

CONCLUSION

Patients with T1D and their FDRs have a high frequency of CDA. Carrying both DR7-DQ2 and DR4-DQ8 was associated with development of CDA in patients with T1D.

Differential immune responses and microbiota profiles in children with autism spectrum disorders and co-morbid gastrointestinal symptoms

OBJECTIVES

Many studies have reported the increased presence of gastrointestinal (GI) symptoms in children with autism spectrum disorders (ASD). Altered microbiome profiles, pro-inflammatory responses and impaired intestinal permeability have been observed in children with ASD and co-morbid GI symptoms, yet few studies have compared these findings to ASD children without GI issues or similarly aged typical developing children. The aim of this study was to determine whether there are biological signatures in terms of immune dysfunction and microbiota composition in children with ASD with GI symptoms.

METHODS

Children were enrolled in one of four groups: ASD and GI symptoms of irregular bowel habits (ASD^GI), children with ASD but without current or previous GI symptoms (ASD^NoGI), typically developing children with GI symptoms (TD^GI) and typically developing children without current or previous GI symptoms (TD^NoGI). Peripheral blood mononuclear cells (PBMC) were isolated from the blood, stimulated and assessed for cytokine production, while stool samples were analyzed for microbial composition.

RESULTS

Following Toll-Like receptor (TLR)-4 stimulation, the ASD^GI group produced increased levels of mucosa-relevant cytokines including IL-5, IL-15 and IL-17 compared to ASD^NoGI. The production of the regulatory cytokine TGFβ1 was decreased in the ASD^GI group compared with both the ASD^NoGI and TD^NoGI groups. Analysis of the microbiome at the family level revealed differences in microbiome composition between ASD and TD children with GI symptoms; furthermore, a predictive metagenome functional content analysis revealed that pathways were differentially represented between ASD and TD subjects, independently of the presence of GI symptoms. The ASD^GI also showed an over-representation of the gene encoding zonulin, a molecule regulating gut permeability, compared to the other groups.

CONCLUSIONS

Overall our findings suggest that children with ASD who experience GI symptoms have an imbalance in their immune response, possibly influenced by or influencing metagenomic changes, and may have a propensity to impaired gut barrier function which may contribute to their symptoms and clinical outcome.

The Prognostic Significance of Increasing Marker Levels in Metastatic Breast Cancer Patients with Clinically Complete Remission, Partial Remission or Stable Disease

TPS, CA 15-3 and CEA were determined in metastatic breast cancer patients during treatment. After six months of follow-up the patients were divided into four groups according to the UICC criteria for treatment response. Forty-six patients with a more favorable prognosis (complete remission, partial remission or stable disease) were followed for an extended period.

In 30 of the 46 patients at least one marker had increased at the end of the six-month period by at least 25% (TPS in 54%, CA 15-3 in 20%, CEA in 20%). All these 30 patients subsequently developed progression. The prognostic sensitivity was 83%, 30% and 30%, respectively, for TPS, CA 15-3 and CEA. The combination of TPS and CA 15-3 showed a sensitivity of 96%. The median lead time was about 8 months for TPS and CA 15-3, but less than 50% of the patients showed a lead time for CA 15-3 as compared to TPS. We conclude that TPS and CA 15-3 determinations are helpful for the prediction of progression during the follow-up of breast cancer patients.

Triceps Tenotomy and Double Plate Stabilization of “Y-T” Fracture of the Humeral Condyle in Three Dogs

Caudal elbow arthrotomy by use of triceps tenotomy was performed for open reduction of “Y-T” fractures of the humeral condyle in three dogs. Stabilization of the fracture was achieved by use of a bone screw inserted with a lag effect to compress the articular fracture and placement of bone plates on the caudolateral surface of the lateral epicondylar crest and the caudomedial surface of the medial epicondylar crest. This construct successfully maintained reduction in all three dogs without implant loosening or breakage. All three of the fractures healed satisfactorily without any evidence of progressive osteoarthritis. Long-term (median - 20 months) function of the affected limb was comparable to the contralateral limb, with little loss of elbow range-of-motion and minimal to an absence of lameness.

Triceps tenotomy was used for open reduction of “Y-T” fractures of the humeral condyle in three dogs. Stabilization of the fracture with a bone screw inserted for lag effect and use of a bone plate on each epicondylar crest resulted in satisfactory healing of the fracture and good limb function in all of the patients.

Zonulin transgenic mice show altered gut permeability and increased morbidity/mortality in the DSS colitis model

Increased small intestinal permeability (IP) has been proposed to be an integral element, along with genetic makeup and environmental triggers, in the pathogenies of chronic inflammatory diseases (CIDs). We identified zonulin as a master regular of intercellular tight junctions linked to the development of several CIDs. We aim to study the role of zonulin-mediated IP in the pathogenesis of CIDs. Zonulin transgenic Hp2 mice (Ztm) were subjected to dextran sodium sulfate (DSS) treatment for 7 days, followed by 4-7 days' recovery and compared to C57Bl/6 (wild-type (WT)) mice. IP was measured in vivo and ex vivo, and weight, histology, and survival were monitored. To mechanistically link zonulin-dependent impairment of small intestinal barrier function with clinical outcome, Ztm were treated with the zonulin inhibitor AT1001 added to drinking water in addition to DSS. We observed increased morbidity (more pronounced weight loss and colitis) and mortality (40-70% compared with 0% in WT) at 11 days post-DSS treatment in Ztm compared with WT mice. Both in vivo and ex vivo measurements showed an increased IP at baseline in Ztm compared to WT mice, which was exacerbated by DSS treatment and was associated with upregulation of zonulin gene expression (fourfold in the duodenum, sixfold in the jejunum). Treatment with AT1001 prevented the DSS-induced increased IP both in vivo and ex vivo without changing zonulin gene expression and completely reverted morbidity and mortality in Ztm. Our data show that zonulin-dependent small intestinal barrier impairment is an early step leading to the break of tolerance with subsequent development of CIDs.

Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases

Beside digesting nutrients and absorbing solutes and electrolytes, the intestinal epithelium with its barrier function is in charge of a tightly controlled antigen trafficking from the intestinal lumen to the submucosa. This trafficking dictates the delicate balance between tolerance and immune response causing inflammation. Loss of barrier function secondary to upregulation of zonulin, the only known physiological modulator of intercellular tight junctions, leads to uncontrolled influx of dietary and microbial antigens. Additional insights on zonulin mechanism of action and the recent appreciation of the role that altered intestinal permeability can play in the development and progression of chronic inflammatory disorders has increased interest of both basic scientists and clinicians on the potential role of zonulin in the pathogenesis of these diseases. This review focuses on the recent research implicating zonulin as a master regulator of intestinal permeability linked to the development of several chronic inflammatory disorders.

Proopiomelanocortin interference in the measurement of adrenocorticotrophic hormone: a United Kingdom National External Quality Assessment Service study

OBJECTIVE

It is recognized that measurement of ACTH-precursor peptides including proopiomelanocortin (POMC) has clinical utility in identifying the aetiology of Cushing's syndrome. Recent data have also demonstrated cross-reactivity of POMC in ACTH immunoassays used in clinical laboratories. The aim of this study was to assess the cross-reactivity of POMC in the main commercial immunoassays for ACTH and to survey the awareness of laboratory professionals to this potential interference.

METHOD

To assess cross-reactivity, specimens containing ACTH and/or POMC were prepared by the UK National External Quality Assessment Service (UK NEQAS) [Edinburgh]. A separate interpretative exercise was also sent to participating laboratories.

RESULTS

Eighty-seven laboratories measured 'total' ACTH (i.e. ACTH and/or POMC) in their assays. Cross-reactivity of POMC varied from a mean of 1·6-4·7% (reflected in a large percentage increase in measured ACTH of up to 261% due to POMC cross-reactivity) depending on the manufacturer. Major differences in the clinical interpretation of test results were observed in returned responses to the interpretative exercise.

CONCLUSION

An appraisal of POMC cross-reactivity in currently available ACTH immunoassays has been achieved. Cross-reactivity was sufficient to detect ACTH precursors at concentrations that could be found in patients with ectopic ACTH syndrome. These data will assist laboratories in interpreting results when assessing the hypothalamic-pituitary-adrenal axis. Endocrinologists and laboratory professionals should be aware of the degree of cross-reactivity in ACTH immunoassay in order to minimize the risk of misinterpretation of results and/or potentially delayed treatment.

Biomarkers of Environmental Enteropathy, Inflammation, Stunting, and Impaired Growth in Children in Northeast Brazil

Critical to the design and assessment of interventions for enteropathy and its developmental consequences in children living in impoverished conditions are non-invasive biomarkers that can detect intestinal damage and predict its effects on growth and development. We therefore assessed fecal, urinary and systemic biomarkers of enteropathy and growth predictors in 375 6–26 month-old children with varying degrees of malnutrition (stunting or wasting) in Northeast Brazil. 301 of these children returned for followup anthropometry after 2-6m. Biomarkers that correlated with stunting included plasma IgA anti-LPS and anti-FliC, zonulin (if >12m old), and intestinal FABP (I-FABP, suggesting prior barrier disruption); and with citrulline, tryptophan and with lower serum amyloid A (SAA) (suggesting impaired defenses). In contrast, subsequent growth was predicted in those with higher fecal MPO or A1AT and also by higher L/M, plasma LPS, I-FABP and SAA (showing intestinal barrier disruption and inflammation). Better growth was predicted in girls with higher plasma citrulline and in boys with higher plasma tryptophan. Interactions were also seen with fecal MPO and neopterin in predicting subsequent growth impairment.

Biomarkers clustered into markers of 1) functional intestinal barrier disruption and translocation, 2) structural intestinal barrier disruption and inflammation and 3) systemic inflammation. Principle components pathway analyses also showed that L/M with %L, I-FABP and MPO associate with impaired growth, while also (like MPO) associating with a systemic inflammation cluster of kynurenine, LBP, sCD14, SAA and K/T. Systemic evidence of LPS translocation associated with stunting, while markers of barrier disruption or repair (A1AT and Reg1 with low zonulin) associated with fecal MPO and neopterin.

We conclude that key noninvasive biomarkers of intestinal barrier disruption, LPS translocation and of intestinal and systemic inflammation can help elucidate how we recognize, understand, and assess effective interventions for enteropathy and its growth and developmental consequences in children in impoverished settings.

Genetics and celiac disease: the importance of screening

The prevalence of celiac disease (CD) is increasing. Despite an increased awareness and an improvement in diagnostic testing, the majority of individuals with CD remain undiagnosed. Currently, genetic testing in screening for CD is used only to exclude a diagnosis or reinforce a strong clinical suspicion. In this paper, we review the most current literature regarding genetic testing in CD. In response to important data revealing that an individual's HLA haplotype is one of the strongest known predictors of CD, we propose genetic screening for at-risk infants to stratify individuals based on genetic risk to ultimately create genetic specific screening algorithms.

Candidate epitopes for measurement of hCG and related molecules: the second ISOBM TD-7 workshop

Participants of the Second International Workshop (WS) on human chorionic gonadotropin (hCG) of the International Society of Oncology and Biomarkers Tissue Differentiation 7 (ISOBM TD-7) have characterized in detail a panel of 69 antibodies (Abs) directed against hCG and hCG-related variants that were submitted by eight companies and research groups. Specificities of the Abs were determined using the First WHO International Reference Reagents for six hCG variants, i.e., hCG, hCGn, hCGβ, hCGβn, hCGβcf, and hCGα, which are calibrated in SI units, and hLH. Molecular epitope localizations were assigned to the ISOBM-mAbs by comparing ISOBM-Ab specificity, sandwich compatibility, and mutual inhibition profiles, to those of 17 reference monoclonal (m)Abs of known molecular epitope specificities. It appeared that 48 Abs recognized hCGβ-, 8 hCGα-, and 13 αβ-heterodimer-specific epitopes. Twenty-seven mAbs were of pan hCG specificity, two thereof with no (<0.1 %; epitope β₁), 12 with low (<1.0 %; epitopes β_2/4), and 13 with high (>>1 %; epitopes β_3/5) hLH cross-reactivity. The majority of hCGβ epitopes recognized were located in two major antigenic domains, one on the peptide chain of the tips of β-sheet loops 1 and 3 (epitopes β_2–6; 27 mAbs) and the second around the cystine knot (e.g., epitopes β₁, β₇, and β₁₀; 9 mAbs). Four mAbs recognized epitopes on hCGβcf-only (e.g., epitopes β₁₁ and β₁₃) and six mAbs epitopes on the remote hCGβ-carboxyl-terminal peptide (epitopes β₈ and β₉ corresponding to amino acids 135–144 and 111–116, respectively). For routine diagnostic measurements, methods are used that either detect hCG-only, hCGβ-only, or hCG together with hCGβ or hCG together with hCGβ and hCGβcf. Sandwich assays that measure hCG plus hCGβ and eventually hCGβcf should recognize the protein backbone of the analytes preferably on an equimolar basis, should not cross-react with hLH and not be susceptible to blunting of signal by nonmeasured variants like hCGβcf. Such assays can be constructed using pairs of mAbs directed against the cystine knot-associated epitope β₁ (Asp10, Asp60, and Gln89) in combination with epitopes β₂ or β₄ located at the top of β-sheet loops 1 + 3 of hCGβ involving aa hCGβ20-25 + 68-77. In summary, the results of the First and Second ISOBM TD-7 WSs on hCG provide the basis for harmonization of specificities and epitopes of mAbs to be used in multifunctional and selective diagnostic hCG methods for different clinical purposes.

Tumor markers in colorectal cancer, gastric cancer and gastrointestinal stromal cancers: European group on tumor markers 2014 guidelines update

Biomarkers currently play an important role in the detection and management of patients with several different types of gastrointestinal cancer, especially colorectal, gastric, gastro-oesophageal junction (GOJ) adenocarcinomas and gastrointestinal stromal tumors (GISTs). The aim of this article is to provide updated and evidence-based guidelines for the use of biomarkers in the different gastrointestinal malignancies. Recommended biomarkers for colorectal cancer include an immunochemical-based fecal occult blood test in screening asymptomatic subjects ≥50 years of age for neoplasia, serial CEA levels in postoperative surveillance of stage II and III patients who may be candidates for surgical resection or systemic therapy in the event of distant metastasis occurring, K-RAS mutation status for identifying patients with advanced disease likely to benefit from anti-EGFR therapeutic antibodies and microsatellite instability testing as a first-line screen for subjects with Lynch syndrome. In advanced gastric or GOJ cancers, measurement of HER2 is recommended in selecting patients for treatment with trastuzumab. For patients with suspected GIST, determination of KIT protein should be used as a diagnostic aid, while KIT mutational analysis may be used for treatment planning in patients with diagnosed GISTs.

Proof of concept of microbiome-metabolome analysis and delayed gluten exposure on celiac disease autoimmunity in genetically at-risk infants

Celiac disease (CD) is a unique autoimmune disorder in which the genetic factors (DQ2/DQ8) and the environmental trigger (gluten) are known and necessary but not sufficient for its development. Other environmental components contributing to CD are poorly understood. Studies suggest that aspects of gluten intake might influence the risk of CD occurrence and timing of its onset, i.e., the amount and quality of ingested gluten, together with the pattern of infant feeding and the age at which gluten is introduced in the diet. In this study, we hypothesize that the intestinal microbiota as a whole rather than specific infections dictates the switch from tolerance to immune response in genetically susceptible individuals. Using a sample of infants genetically at risk of CD, we characterized the longitudinal changes in the microbial communities that colonize infants from birth to 24 months and the impact of two patterns of gluten introduction (early vs. late) on the gut microbiota and metabolome, and the switch from gluten tolerance to immune response, including onset of CD autoimmunity. We show that infants genetically susceptible to CD who are exposed to gluten early mount an immune response against gluten and develop CD autoimmunity more frequently than at-risk infants in which gluten exposure is delayed until 12 months of age. The data, while derived from a relatively small number of subjects, suggest differences between the developing microbiota of infants with genetic predisposition for CD and the microbiota from infants with a non-selected genetic background, with an overall lack of bacteria of the phylum Bacteriodetes along with a high abundance of Firmicutes and microbiota that do not resemble that of adults even at 2 years of age. Furthermore, metabolomics analysis reveals potential biomarkers for the prediction of CD. This study constitutes a definite proof-of-principle that these combined genomic and metabolomic approaches will be key to deciphering the role of the gut microbiota on CD onset.

Natural history of celiac disease autoimmunity in a USA cohort followed since 1974

BACKGROUND

The natural history and the possible changes of celiac disease (CD) prevalence over time are still unclear.

OBJECTIVES

1) To establish whether loss of tolerance to gluten may occur at any age; 2) to investigate possible changes of CD prevalence over time; and 3) to investigate CD-related co-morbidities.

METHODS

We analyzed 3,511 subjects with matched samples from 1974 (CLUE I) and 1989 (CLUE II). To avoid a selection bias regarding survival, we also screened 840 CLUE I participants who deceased after the 1974 survey. Outcome measure. CD autoimmunity (positivity to auto-antibodies) over time.

RESULTS

CD autoimmunity was detected in seven subjects in 1974 (prevalence 1:501) and in an additional nine subjects in 1989 (prevalence 1:219). Two cases of CD autoimmunity were found among the 840 subjects deceased after CLUE I. Compared to controls, untreated CD subjects showed increased incidence of osteoporosis and associated autoimmune disorders, but they did not reach statistical significance.

CONCLUSIONS

During a 15-year period CD prevalence increased 2-fold in the CLUE cohort and 5-fold overall in the US since 1974. The CLUE study demonstrated that this increase was due to an increasing number of subjects that lost the immunological tolerance to gluten in their adulthood.

Characterization of intestinal distension in ELT-2kd Caenorhabditis elegans upon infection with Pseudomonas aeruginosa (43.27)

Caenorhabditis elegans has become a popular model for studying innate immunity. Recently, the transcription factor ELT-2, which is homologous to human GATA-4, -5 and -6, has been shown to play a role in the nematode immune response, along with its established role in intestinal development. One characteristic of ELT-2’s role in innate immunity is the accumulation of bacteria and distension of the intestinal lumen when ELT-2 is downregulated in the nematode by RNA interference. However, the mechanism of this distension remains unclear. In this study, we characterize the timeline of intestinal distension in ELT-2kd and ELT-7kd nematodes during Pseudomonas aeruginosa infection. We show that intestinal distension is seen in ELT-2kd but not ELT-7kd nematodes during P. aeruginosa infection. Significant distension in ELT-2kd nematodes is seen within 30 hours of pathogen exposure. A detailed comparison of this distension with survival of the nematodes on the pathogen will be presented. These data provide new insight into the role of ELT-2 in protecting C. elegans against pathogenic bacteria.

Adequate surgery for papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer, occurring in about 80% of cases. Treatment consists ofsurgery, selective adjuvant radioiodine ablation, thyroid stimulating hormone suppression and surveillance. The extent of thyroidectomy and the extent of lymphadenectomy are controversial. Total or near-total thyroidectomy is recommended for the treatment of PTC, except those with papillary microcarcinoma (PTC < 1 cm) found incidentally after a thyroid lobectomy. This allows for treatment of possible multifocality (up to 8o% of cases), facilitates the use of radioiodine for remnant ablation and increases the sensitivity of thyroglobulin levels for surveillance, with complication rates comparable to lobectomy when done by experienced endocrine surgeons. A recent large database study supports this recommendation for PTCs > or = 1 cm; the optimal treatment of PTCs < 1 cm is still debatable, though many surgeons will perform total or near-total thyroidectomy for the reasons listed above. Contemporary series report lymph node metastases in up to 64% of patients, though their clinical significance is unclear. Reports are conflicting with respect to the impact of cervical nodal metastases on recurrence rates and survival, which are also affected by other patient, tumour and treatment-related factors. Therapeutic lymph node dissection is indicated for biopsy-proven nodal metastases. Prophylactic lateral neck lymphadenectomy is not recommended by experts in Europe and the USA. Prophylactic central neck lymphadenectomy is controversial, and may be advocated in selected patients while balancing the risks of the procedure.

Tumor markers in pancreatic cancer: a European Group on Tumor Markers (EGTM) status report

Pancreatic ductal adenocarcinoma is one of the most difficult malignancies to diagnose and treat. The aim of this article is to review how tumor markers can aid the diagnosis and management of patients with this malignancy. The most widely used and best validated marker for pancreatic cancer is CA 19-9. Inadequate sensitivity and specificity limit the use of CA 19-9 in the early diagnosis of pancreatic cancer. In non-jaundiced patients, however, CA 19-9 may complement other diagnostic procedures. In patients with resectable pancreatic cancer, presurgical and postresection CA 19-9 levels correlate with overall survival. In advanced disease, elevated pretreatment levels of CA 19-9 are associated with adverse patient outcome and thus may be combined with other factors for risk stratification. Most, but not all, reports indicate that serial levels of CA 19-9 correlate with response to systemic therapy. Use of CA 19-9 kinetics in conjunction with imaging is therefore recommended in monitoring therapy. Although several potential serum and tissue markers for pancreatic cancer are currently undergoing evaluation, none are sufficiently validated for routine clinical use. CA 19-9 thus remains the serum pancreatic cancer marker against which new markers for this malignancy should be judged.

Significance of serum CA125 and TPS antigen levels for determination of overall survival after three chemotherapy courses in ovarian cancer patients during long-term follow-up

PURPOSE OF INVESTIGATION

To evaluate the prognostic significance for overall survival rate for the marker combination TPS and CA125 in ovarian cancer patients after three chemotherapy courses during long-term clinical follow-up.

METHODS

The overall survival of 212 (out of 213) ovarian cancer patients (FIGO Stages I-IV) was analyzed in a prospective multicenter study during a 10-year clinical follow-up by univariate and multivariate analysis.

RESULTS

In patients with ovarian cancer FIGO Stage I (34 patients) or FIGO Stage II (30 patients) disease, the univariate and multivariate analysis of the 10-year overall survival data showed that CA125 and TPS serum levels were not independent prognostic factors. In the FIGO Stage III group (112 patients), the 10-year overall survival was 15.2%; while in the FIGO Stage IV group (36 patients) a 10-year overall survival of 5.6% was seen. Here, the tumor markers CA125 and TPS levels were significant prognostic factors in both univariate and multivariate analysis (p < 0.0001). In a combined FIGO Stage III + FIGO Stage IV group (60 patients with optimal debulking surgery), multivariate analysis demonstrated that CA125 and TPS levels were independent prognostic factors. For patients in this combined FIGO Stage III + IV group having both markers below respective discrimination level, 35.3% survived for more than ten years, as opposed to patients having one marker above the discrimination level where the 10-year survival was reduced to 10% of the patients. For patients showing both markers above the respective discrimination level, none of the patients survived for the 10-year follow-up time.

CONCLUSION

In FIGO III and IV ovarian cancer patients, only patients with CA 125 and TPS markers below the discrimination level after three chemotherapy courses indicated a favorable prognosis. Patients with an elevated level of CA 125 or TPS or both markers after three chemotherapy courses showed unfavorable prognosis.

A clinical study assessing the tolerability and biological effects of infliximab, a TNF-alpha inhibitor, in patients with advanced cancer

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective.

PATIENTS AND METHODS

Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP).

RESULTS

Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient.

CONCLUSIONS

Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response.

Tumour markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines for clinical use

The aim of this article is to present updated guidelines for the use of serum, tissue and faecal markers in colorectal cancer (CRC). Lack of specificity and sensitivity preclude the use of all existing serum markers for the early detection of CRC. For patients with stage II or stage III CRC who may be candidates for either liver resection or systemic treatment should recurrence develop, CEA should be measured every 2-3 months for at least 3 years after diagnosis. Insufficient evidence exists to recommend routine use of tissue factors such as thymidylate synthase, microsatellite instability (MSI), p53, K-ras and deleted in colon cancer (DCC) for either determining prognosis or predicting response to therapy in patients with CRC. Microsatellite instability, however, may be used as a pre-screen for patients with suspected hereditary non-polyposis colorectal cancer. Faecal occult blood testing but not faecal DNA markers may be used to screen asymptomatic subjects 50 years or older for early CRC.

Cyclosporine treatment of anal furunculosis in 26 dogs

OBJECTIVES

To evaluate the effect of cyclosporine on anal furunculosis lesions in 26 dogs.

METHODS

Lesions were graded as mild in 11 dogs, moderate in eight and severe in seven. Each dog was treated with approximately 4 mg/kg cyclosporine orally every 12 hours until the lesions resolved or showed no further improvement. Residual lesions were resected surgically.

RESULTS

Eighteen dogs (69 per cent) experienced complete resolution, seven (27 per cent) improved but had residual lesions and one (4 per cent) showed no improvement. The mean duration of treatment until resolution or no further improvement was 8.8 weeks (range four to 24 weeks). Nine dogs (35 per cent) experienced recurrence. Six were from the group that had shown complete resolution and three were from the group that had surgery. Fifteen dogs (58 per cent) developed side effects to cyclosporine, although none required treatment to be discontinued. Mean duration of follow-up was 6.8 months (range one to 20 months).

CLINICAL SIGNIFICANCE

Cyclosporine was effective at resolving or reducing anal furunculosis lesions in 25 of 26 dogs (96 per cent). However, residual or recurrent lesions remain a potential problem, and surgical resection or long-term cyclosporine treatment may be necessary in some dogs.

Clinical utility of biochemical markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines

In recent years, numerous serum and cell/tissue-based markers have been described for colorectal cancer (CRC). The aim of this article was to provide guidelines for the routine clinical use of some of these markers. Lack of sensitivity and specificity preclude the use of any available serum markers such as carcinoembryonic antigen (CEA), CA 19-9, CA 242, CA 72-4, tissue polypeptide antigen (TPA) or tissue polypeptide-specific antigen (TPS) for the early detection of CRC. However, preoperative measurement of CEA is desirable as this may give independent prognostic information, help with surgical management and provide a baseline level for subsequent determinations. For patients with stage 2 (Dukes' B) and 3 (Dukes' C) disease who may be candidates for liver resection, CEA levels should be measured every 2-3 months for at least 3 years after diagnosis. For monitoring treatment of advanced disease, CEA should also be tested every 2-3 months. Insufficient evidence is presently available to recommend the routine use of other serum markers for monitoring purposes. Similarly, the new cell and tissue-based markers (e.g, ras, P53) cannot yet be recommended for routine clinical use.

The ISOBM TD-7 Workshop on hCG and related molecules. Towards user-oriented standardization of pregnancy and tumor diagnosis: assignment of epitopes to the three-dimensional structure of diagnostically and commercially relevant monoclonal antibodies directed against human chorionic gonadotropin and derivatives

The ISOBM TD-7 hCG Workshop was established to characterize the molecular epitope structure and specificities of a panel of diagnostically relevant monoclonal antibodies (MAbs) directed against human chorionic gonadotropin (hCG) and its derivatives, and to consider how this information could be used to improve comparability of immunoassay results for these analytes. In this multicenter study, 27 MAbs have been characterized in detail as to their main and fine specificities by direct binding-, competitive- and sandwich-RIA, -ELISA, BIAcore and Western blotting. Antigens used in the study included the upcoming first WHO reference reagents for immunoassay, i.e. nick-free hCG (hCG), nicked hCG (hCGn), hCG alpha-subunit (hCGalpha), hCG beta-subunit (hCGbeta), nicked hCG beta-subunit (hCGbetan), hCG beta-core fragment (hCGbetacf), synthetic peptides of hCGbeta C-terminal peptide (hCGbetaCTP), and homologous hormones, luteinizing hormone (LH) and subunits (LHbeta) from various species. Correct classification of blinded internal controls demonstrated the reliability of the MAb referencing approach. Three-dimensional molecular epitope assignment was possible in many instances by comparing immunoreactivity of the ISOBM MAbs (n = 27) to a large panel of MAbs (n = 18) previously well characterized in the Innsbruck (P.B.) and Paris (J.M.B.) laboratories. All three major antibody specificities (alpha, n = 1; beta, n = 21; alphabeta, n = 5) were represented in the TD-7 MAb panel. HCGbeta MAbs could further be subdivided into (i) those recognizing hCGbeta only (epitopes: beta(6), n = 1; beta(7), n = 2; beta(14), n = 1) and (ii) those recognizing hCGbeta + hCG (beta1, beta2, beta4, beta5, n = 10; beta8 and beta9, n = 9). Members of the latter group were specific either for hCG + hCGbeta + hCGbetacf (beta1, n = 3) or hCG + hCGbeta + hCGbetaCTP (beta8, n = 6; beta9, n = 1) or in addition to hCG + hCGbeta + hCGbetacf recognized hLH/hLHbeta to a minor (beta2, n = 3; beta4, n = 3) or similar degree (beta5, n = 1). Epitopes were (i) located on the first and third loops protruding from the cystine knot of hCGbeta (beta2-beta6, aa hCGbeta20-25 and 68-77), (ii) presumably centered around the knot itself (beta1), or (iii) on hCGbetaCTP (epitope beta8 = hCGbeta141-144, beta9 = hCGbeta113-116). The ISOBM panel of MAbs represents all major epitope specificities suitable for the design of specific sandwich immunoassays. High analyte variability in serum and urine during the course of pregnancy and tumor development favors certain epitope combinations. For routine diagnostic purposes, assays recognizing a broad spectrum of hCG/hCGbeta variants such as hCG + hCGn + hCGbeta + hCGbetan + hCGbetacf + -CTPhCG + -CTPhCGbeta may be useful. Low cross-reactivity against related glycoprotein hormones (e.g. hLH) and their derivatives is mandatory. These criteria are best met by combinations of MAbs directed against epitopes located around the cystine knot (beta1) and against those encompassing the top of loops 1 and 3 on hCGbeta (beta2, beta4). The first WHO reference reagents for immunoassay of hCG and hCG-related molecules being prepared by the IFCC should facilitate characterization of what assays for 'hCG' are measuring. The next step towards improving between-laboratory comparability of measurements of hCG/hCG derivatives in pregnancy and oncology is provided by results of this TD-7 Workshop.

Baboon mesenchymal stem cells can be genetically modified to secrete human erythropoietin in vivo

Human mesenchymal stem cells (MSCs) are capable of differentiating into multiple mesenchymal lineages including chondrocytes, osteocytes, adipocytes, and marrow stromal cells. Using a nonhuman primate model, we evaluated nonhuman primate MSCs as targets for gene therapy. Baboon MSCs (bMSCs) cultured from bone marrow aspirates appeared as a homogeneous population of spindle-shaped cells. bMSCs were capable of differentiating into adipocytes and osteocytes in vitro and chondrocytes in vivo. bMSCs were genetically modified with a bicistronic vector encoding the human erythropoietin (hEPO) gene and the green fluorescent protein (GFP) gene. Transduction efficiencies ranged from 72 to 99% after incubation of MSCs with retroviral supernatant. Transduced cells produced from 1.83 x 10(5) to 7.12 x 10(5) mIU of hEPO per 10(6) cells per 24 hr in vitro before implantation. To determine the capacity of bMSCs to express hEPO in vivo, transduced bMSCs were injected intramuscularly in NOD/SCID mice. In a separate experiment, transduced bMSCs were loaded into immunoisolatory devices (IIDs) and surgically implanted into either autologous or allogeneic baboon recipients. Human EPO was detected in the serum of NOD/SCID mice for up to 28 days and in the serum of five baboons for between 9 and 137 days. NOD/SCID mice experienced sharp rises in hematocrit after intramuscular injection of hEPO-transduced bMSCs. The baboon that expressed hEPO for 137 days experienced a statistically significant (p < 0.04) rise in its hematocrit. These data demonstrate that nonhuman primate MSCs can be engineered to deliver a secreted and biologically active gene product. Therefore, human MSCs may be an effective target for future human gene therapy trials.

The relative quiescence of hematopoietic stem cells in nonhuman primates

Quiescence has been thought to be required for the retention of the full biological potential of pluripotent hematopoietic stem cells (PHSCs). This hypothesis has been challenged recently by the observation that all murine PHSCs cycle continuously and constantly contribute to steady-state blood cell production. It was asked whether these observations could be extrapolated to describe hematopoiesis in higher mammals. In this series of experiments, the replicative history of PHSCs was examined in baboons by continuously administering bromodeoxyuridine (BrdU) for more than 85 weeks. The results indicate that under steady-state conditions, PHSCs remain largely quiescent but do cycle, albeit at a far lower rate than previously reported for rodent PHSCs. BrdU-labeled cycling PHSCs and progenitor cells were shown to have an extensive proliferative capacity and to contribute to blood cell production for prolonged periods of time. The proportion of PHSCs entering cell cycle could, however, be rapidly increased by the in vivo administration of granulocyte-colony stimulating factor. These data indicate that during steady-state hematopoiesis, baboon PHSCs require prolonged periods of time to cycle and that the proportion of PHSCs in cycle is not fixed but can be altered by external stimuli. The relative quiescence of PHSCs observed in this nonhuman primate model, in contrast to murine PHSCs, might explain the current barriers to genetic modification and ex vivo expansion of human PHSCs.

Mesenchymal stem cells are capable of homing to the bone marrow of non-human primates following systemic infusion

OBJECTIVE

The human bone marrow contains mesenchymal stem cells capable of differentiating along multiple mesenchymal cell lineages. Using a non-human primate model, we sought to determine whether the systemic infusion of baboon-derived mesenchymal stem cells was associated with toxicity and whether these cells were capable of homing to and persisting within the bone marrow.

MATERIALS AND METHODS

Five baboons (Papio anubis) were administered lethal irradiation followed by intravenous autologous hematopoietic progenitor cells combined with either autologous (n = 3) or allogeneic (n = 2) mesenchymal stem cells that had been expanded in culture. In four of these baboons, the mesenchymal stem cells were genetically modified with a retroviral vector encoding either the enhanced green fluorescent protein gene (n = 3) or the human placental alkaline phosphatase gene (n = 1) for tracking purposes. A sixth animal received only intravenous gene marked autologous mesenchymal stem cells but no hematopoietic stem cells or conditioning irradiation.

RESULTS

Following culture, baboon mesenchymal stem cells appeared morphologically as a homogeneous population of spindle-shaped cells that were identified by the monoclonal antibodies SH-3 and SH-4. These cells did not express the hematopoietic markers CD34 or CD45. Baboon mesenchymal stem cells isolated from primary culture were capable of differentiating along both adipogenic and osteogenic lineages. There was no acute or chronic toxicity associated with the intravenous infusion of mesenchymal stem cells. In all five recipients of gene marked mesenchymal stem cells, transgene was detected in post-transplant bone marrow biopsies. In two animals receiving autologous mesenchymal stem cells, including the one non-conditioned recipient, transgene could be detected over 1 year following infusion. In one recipient of allogeneic gene marked mesenchymal stem cells, transgene was detected in the bone marrow at 76 days following infusion.

CONCLUSION

These data demonstrate that baboon mesenchymal stem cells: 1) are not associated with significant toxicity when administered intravenously, 2) are capable of homing to the bone marrow following intravenous infusion, and 3) have the capacity to establish residence within the bone marrow for an extended duration following systemic administration.

Prognostic significance of CA 125 and TPS levels after 3 chemotherapy courses in ovarian cancer patients

OBJECTIVE

To evaluate the prognostic significance of and predictive value for survival of CA 125 and TPS levels after three chemotherapy courses in ovarian cancer patients.

METHODS

We analyzed in a prospective multicenter study the 1- and 2-year overall survival (OS) in ovarian carcinoma patients. The prognostic significance of CA 125 and TPS levels above the discrimination value (25 kU/L and 100 U/L, respectively) was examined by univariate and multivariate analyses.

RESULTS

Of the 213 cases included, 64 patients were staged as FIGO I + II and 149 patients were staged as FIGO III + IV. Tumor marker levels in stage I + II were not correlated with survival. However, stage III and IV patients with elevated levels of CA 125 or TPS after three chemotherapy courses had a worse 2-year OS (69% vs 26%, P < 0.0001 and 57% vs 20%, P < 0.0001, respectively) than patients with normal levels of the markers. In univariate analysis the result of operation (staging laparatomy and partial debulking) and advanced FIGO stage (IV) were also adverse prognostic factors. Independent factors predictive of low 2-year OS by multivariate analysis were staging laparotomy, TPS elevated, and CA 125 elevated. The only factors predictive of low 1-year OS were TPS elevated and staging laparotomy.

CONCLUSIONS

Ovarian cancer patients with elevated CA 125 levels after three chemotherapy courses have a poor prognosis. However, the prognostic accuracy can be significantly increased by the parallel determination of serum TPS.

Serum levels of CA 125 and TPS during treatment of ovarian cancer

Two hundred and sixty ovarian cancer patients (including all FIGO stages) were enrolled in a prospective multicentre study. In this interim study we analyzed 206 patients receiving combined chemotherapy for at least 3 courses for two-year overall survival (OS). CA 125 and TPS were applied for monitoring treatment and the relationship between marker levels, marker changes and clinical assessments was established. Preoperative CA 125 or TPS levels were not correlated with OS in FIGO stage I and II patients. After 3 chemotherapy courses the marker levels were not correlated with OS in stage I and II. Partial debulking in stage II patients was a bad prognostic factor. CA 125 or TPS levels (using a CA 125 discrimination level of 25 kU/l and a TPS discrimination level of 100 U/l) after 3 courses of chemotherapy were highly significantly correlated with OS in FIGO stages III and IV patients: CA 125 two-year OS 67% versus 26% (p < 0.0001) and TPS two-year OS 55% versus 22% (p < 0.0001). The prognostic value of CA 125 levels after 3 chemotherapy courses could be further increased by combining CA 125 and TPS levels. When both CA 125 and TPS levels were below their respective discrimination levels, the two-year overall survival was 75%. When both levels were above the discrimination level, the two-year overall survival was only 17%.

Use of the bisphosphonate drug alendronate for palliative management of osteosarcoma in two dogs

The bisphosphonate drug alendronate was used to suppress bone remodelling and tumour osteolysis as a palliative treatment for two dogs with osteosarcoma, one of the tibia and one of the maxilla. A spiral fracture associated with the tibial tumour healed after it was stabilised with an external skeletal fixator. Both dogs remained comfortable and survived for 12 and 10 months respectively after diagnosis, despite the fact that neither primary tumour was resected.

Bacterial contamination of suction tips used during surgical procedures performed on dogs and cats

OBJECTIVE

To determine prevalence of bacterial contamination of surgical suction tips.

SAMPLE POPULATION

Surgical tips used during 44 surgical procedures performed on 42 dogs and 2 cats.

PROCEDURE

Surgical procedures were classified into 1 of 3 categories according to degree of bacterial contamination of the surgical site (clean, clean-contaminated, contaminated). Two sets of suction apparatuses were used for test and control suction tips. Test tips were used normally to suction blood and fluid, whereas control tips were placed on the surgical drapes but not in the surgical wound. Suction tips were collected aseptically and placed into thioglycolate broth tubes for qualitative aerobic and anaerobic bacterial culture at the end of each procedure.

RESULTS

Test and control suction tips were contaminated with bacteria during 30 of 44 (68%) procedures. Staphylococcus spp were the predominant bacteria in tips used during clean and clean-contaminated surgeries. When surgery was performed on clean-contaminated or contaminated wounds, prevalence of isolation of other bacteria such as Pseudomonas spp, Streptococcus spp, and Escherichia coli from both test and control suction tips was higher than for clean wounds. Mean time of procedures during which both test and control suction tips became contaminated was not significantly different from time of procedures during which neither tip became contaminated.

CONCLUSION AND CLINICAL RELEVANCE

Surgical suction tips often become contaminated during standard veterinary surgical procedures. The risk of wound infection after surgery may be influenced by bacterial contamination of surgical suction tips.

Prognostic significance of CA 125 and TPS levels after chemotherapy in ovarian cancer patients

The analysis of survival data of patients with epithelial ovarian cancer proved that both CA 125 and TPS were good markers for clinical outcome prediction. Patients receiving chemotherapy were analyzed for 2-year overall survival (OS). Kaplan-Meier survival analysis showed highly significant differences in OS between patients with stage I+II (survival for 2 years 68%) and stage III+IV (survival for 2 years 33%; p = 0.0008). CA 125 levels above or below 35 kU/I and TPS levels above or below 80 U/l after 3 chemotherapy courses were not significantly correlated with OS in stage I+II patients (p = 0.06 respectively 0.07). However, in the subgroup of patients with stage III+IV the cut-off levels of CA 125 and TPS were excellent discriminators of OS: With CA 125 levels below the cut-off 52% of the patients survived, while with CA 125 levels above the cut-off only 13% survived (p < 0.0001). With TPS levels below the cut-off 49% of the patients survived, while with levels above the cut-off only 19% of the patients survived (p < 0.0001). In the subset of patients with CA 125 levels less than 35 kU/I after 3 chemotherapy courses (n = 50) analysis of their TPS levels allowed further discrimination of the prognostic significance. With TPS levels below the cut-off 63% of the patients survived, while 35% of the patients survived with TPS levels above the cut-off. The sum value of CA 125 and TPS cut-off values (115) as discriminator correlated even better with survival rate: With levels below this sum value 63% of the patients survived, while this was only 17% with sum values above the summed cut-off level (p = 0.0004). The extent to which the tumor was removed at operation also correlated with the 2 years survival rate. None of the patients with a staging laparotomy (n = 10) showed a 2-years survival. The difference in OS between patients with complete debulking and partial debulking was significant: OS 51% versus 23% (p = 0.027). Prognosis was not significantly correlated with histological type.

Depressed myofilament co-operativity associated with post-cardioplegic myocardial depression

The mechanism underlying myocardial depression after procedures involving cardioplegia are unknown. We tested the hypothesis that such depression was associated with altered myofilament interactions, using isolated hearts perfused with warm (37 degreesC), oxygenated (95% O2/5% CO2) Krebs-Ringer's bicarbonate (KRB) buffer. A latex balloon was inserted into the left ventricle (LV) to monitor LV function. All hearts underwent a 30-min equilibration period. One group of hearts (CPL+RPR) were arrested with St Thomas #2 cardioplegic solution (4 degreesC; 3 ml followed by 1 ml every 15 min) for 120 min, followed by reperfusion with warm, oxygenated KRB. A second group underwent cardioplegic arrest with no reperfusion (CPL). A third group underwent 60 min of warm, oxygenated perfusion with KRB beyond the equilibration period (60 MIN). The last group only underwent the equilibration period (EQUIL). LV function was assessed at the end of equilibration, and at 30 and 60 min of reperfusion (or 30 and 60 min additional perfusion in the 60 MIN group). All hearts were frozen at the end of the temporal protocol for each group, and stored at -70 degreesC for later measurement of Ca2+-stimulated Mg2+ ATPase activity after isolation of myofibrils. CPL+RPR hearts demonstrated significant depression of systolic pressure and elevation diastolic pressure at fixed volumes, compared to baseline and 60 MIN group values. There were no significant changes in the amount of constituent myofilament proteins, as assessed by densinometric analyses of Western blots. There were also no changes in the minimal or maximal ATPase activities, nor in the pCa50, indicating no effect of cardioplegic arrest on myofilament sensitivity to calcium. However, all hearts that underwent cardioplegic arrest were found to have significantly lower Hill coefficients (1.85+/-0.09 and 1.85+/-0.13 v 2.31+/-0.13 and 2.34+/-0. 14 in CPL+RPR and CPL v 60 MIN and EQUIL hearts, respectively), suggesting decreased co-operativity of the actomyosin interaction. Such a decrease in co-operativity would contribute to both the systolic and diastolic alterations associated with myocardial depression after cardioplegic arrest. These changes were associated with the cardioplegic event, and appeared to be independent of reperfusion.

Rapid determination of glomerular filtration rate by single-bolus inulin: a comparison of estimation analyses

Rapid measurement of glomerular filtration rate (GFR) by an inulin single-bolus technique would be useful, but its accuracy has been questioned. We hypothesized that reported inaccuracies reflect the use of inappropriate mathematical models. GFR was measured in 14 intact and 5 unilaterally nephrectomized conscious male Sprague-Dawley rats (mean weight 368 +/- 12 g) by both single-bolus (25 mg/kg) and constant-infusion techniques (0.693 mg . kg-1 . min-1). The temporal decline in plasma inulin concentration was analyzed through biexponential curve fitting, which accounted for renal inulin loss before complete vascular and interstitial mixing. We compared our mathematical model based on empirical rationale with those of other investigators whose studies suggest inaccuracy of single-bolus methods. Our mathematical model yielded GFR values by single bolus that agreed with those obtained by constant infusion [slope = 0.94 +/- 0.16 (SE); y intercept = 0.23 +/- 0.64; r = 0.82]. In comparison to the data obtained by constant inulin infusion, this method yielded a very small bias of -0.0041 +/- 0.19 ml/min. Two previously reported models yielded unsatisfactory values (slope = 1. 46 +/- 0.34, y intercept = 0.47 +/- 1.5, r = 0.72; and slope = 0.17 +/- 1.26, y intercept = 17.15 +/- 5.14, r = 0.03). The biases obtained by using these methods were -2.21 +/- 0.42 and -13.90 +/- 1. 44 ml/min, respectively. The data indicate that when appropriate mathematical models are used, inulin clearance after single-bolus delivery can be used to measure GFR equivalent to that obtained by constant infusion of inulin. Attempts to use methods of analysis for simplicity or expediency can result in unacceptable measurements relative to the clinical range of values seen.

Pregnant women with impaired tolerance to an oral glucose load in the afternoon: evidence suggesting that they behave metabolically as patients with gestational diabetes

OBJECTIVE

In previous studies we observed the existence of a circadian variation of the blood glucose response to oral glucose in pregnant women with higher values at 4 PM. Some women with increased risk of diabetes with normal oral glucose tolerance tests at 8 AM also had values above maximum normal levels at 4 PM. The aim of this trial was to determine the clinical significance of this impaired tolerance in the afternoon.

STUDY DESIGN

Seventy-seven pregnant women with normal risk of diabetes (65 of normal weight and 12 overweight), 75 with increased risk of diabetes (26 overweight), and 12 patients with gestational diabetes were incorporated in the study. All women underwent two oral glucose tolerance tests (1.5 gm/kg) at 31 to 32 weeks' gestation at 8 AM and 4 PM with a 1-week interval. At 33 weeks' gestation a whole-day blood glucose profile was performed with usual food intake; samples were withdrawn before each meal and at 30, 60, and 120 minutes after each meal. The weight of the newborns was recorded.

RESULTS

(1) Results of oral glucose tolerance tests confirmed a circadian variation of the response in all groups; (2) 37 women with increased risk of diabetes had higher values after oral glucose tolerance testing than the normal threshold at 4 PM but not at 8 AM; (3) among women with normal risk of diabetes all values were within the normal range despite the circadian variation; (4) blood glucose levels during whole-day profiles were normal in women with normal risk of diabetes and with increased risk of diabetes with normal oral glucose tolerance testing at 4 PM, whereas all women with increased risk of diabetes and impaired tolerance in the afternoon showed hyperglycemic episodes; (5) the percentage of newborns with high weight (>90th percentile) among women with increased risk of diabetes and abnormal oral glucose tolerance tests at 4 PM was similar to the percentage found in women with gestational diabetes and much higher than the one observed in women with normal oral glucose tolerance tests in the afternoon.

CONCLUSIONS

The impairment of the response to oral glucose tolerance testing seen in some patients with increased risk of diabetes at 4 PM but not at 8 AM seems of clinical significance in view of the abnormal whole-day blood glucose profile these women had and the weights of the newborns.

Cardiac contractile function during coronary stenosis in dogs: association of adenosine in glycolytic dependence

We tested the hypothesis that during critical coronary stenosis, endogenous adenosine alters myocardial glucose utilization to support myocardial contractile function (MCF). Anesthetized mongrel dogs were instrumented to measure hemodynamic variables, regional MCF (sonomicrometry), and substrate uptakes. Critical coronary artery stenosis was established with a screw clamp on the left circumflex coronary artery (LCX). Either 8-phenyltheophylline (3 x 10(-7) mol/min; adenosine-receptor blockade), iodoacetate (1 x 10(-5) mol/min; glycolysis blockade), or vehicle was infused into the LCX and the left anterior descending coronary artery (LAD). Critical coronary stenosis caused small decreases in arterial blood pressure and LCX blood flow, but no significant changes in MCF or other hemodynamics. There was a significant decrease in the O2 supply-to-consumption ratio in the stenotic region and an increased glucose uptake. Infusion of either 8-phenyltheophylline or iodoacetate caused a decrease in MCF in the stenotic LCX region concomitant with a decreased glucose uptake and without further changes in blood flow. This was not seen in the nonstenotic (LAD) region. These data support the hypothesis, indicating that glycolysis is vital for maintaining regional MCF during a decrease in the myocardial O2 supply-to-consumption ratio and that adenosine is important in this regard, independent of its vasoactive properties.