[Breast pilomatrixoma manifested as microcalcifications on mammography: report of two cases]. / Pilomatricomes mammaires révélés par des microcalcifications à la mammographie: à propos de deux cas.

Pilomatricoma is a benign tumor of hair follicule origin corresponding to a firm subcutaneous nodule requiring histology for diagnosis. Only few breast pilomatricomas have been reported, with imaging showing well defined nodules with microcalcifications. We report two cases of intra-mammary pilomatricomas presenting as ACR BI-RADS 4 and 5 microcalcifications, suspicious for malignant tumors. Percutaneous biopsy confirmed the histological diagnosis. Malignant pilomatricomas have been reported, suggesting that all pilomatricomas should be resected.

[Can US-guided vacuum-assisted biopsies be an alternative to diagnostic surgery in cases of non-diagnostic core needle biopsy?]. / Les macrobiopsies echoguidées assistées par le vide peuvent-elles constituer une alternative a la chirurgie diagnostique en cas de microbiopsies non contributives?

PURPOSE: To assess US-guided vacuum-assisted biopsies in the diagnosis of suspicious sonographic breast lesions after non-diagnostic core needle biopsies (CNB). PATIENTS AND METHODS: Retrospective study of 42 females with suspicious breast lesions at US. CNB previously performed were non-diagnostic. Because of the larger sample size, vacuum-assisted biopsies were performed, instead of surgical biopsy. RESULTS: Vacuum-assisted biopsies showed 32 benign lesions. Histologic examination of the CNB showed non-specific fibrous tissue in 43% of cases as opposed to 7.1% for vacuum-assisted biopsies. The latter provided a more specific diagnosis (mainly fibrocystic breast disease). From a total of 4 lesions that were suspicious at CNB, 3 were diagnosed as malignancies after vacuum-assisted biopsy and one case was a "borderline" lesion. Three additional malignant and three additional borderline lesions were diagnosed on vacuum-assisted biopsies. In 11 cases, surgical excision was performed, and all diagnoses from vacuum-assisted biopsies were confirmed at microscopy, except in one case where it was underestimated (ADH versus DCIS). CONCLUSION: US-guided vacuum-assisted biopsy is a reliable technique. Because it provides more tissue than CNB, it can be an alternative to diagnostic surgery after non-diagnostic CNB. Indeed, it allows confirmation of the diagnosis and provides a more specific diagnosis of benign lesions. With regards to malignant and borderline lesions, it avoids the risk of false-negative CNB and overlooking carcinomas.

Involvement of glycosylation in the intracellular trafficking of glycoproteins in polarized epithelial cells.

The surface of epithelial cells is composed of apical and basolateral domains with distinct structure and function. This polarity is maintained by specific sorting mechanisms occurring in the Trans-Golgi Network. Peptidic signals are responsible for the trafficking via clathrin-coated vesicles by means of an interaction with an adaptor complex (AP). The basolateral targeting is mediated by AP-1B, which is specifically expressed in epithelial cells. In contrast, the apical targeting is proposed to occur via apical raft carriers. It is thought that apically targeted glycoproteins contain glycan signals that would be responsible for their association with rafts and for apical targeting. However, the difficulty in terms of acting specifically on a single step of glycosylation did not allow one to identify such a specific signal. The complete inhibition of the processing of N-glycans by tunicamycin often results in an intracellular accumulation of unfolded proteins in the Golgi. Similarly, inhibition of O-glycosylation can be obtained by competitive substrates which gave a complex pattern of inhibition. Therefore, it is still unknown if glycosylation acts in an indirect manner, i.e. by modifying the folding of the protein, or in a specific manner, such as an association with specific lectins.

[Value of ultrasound detection of post-Mammotome scar for preoperative localization of breast microcalcifications]. / Intérêt de la recherche échographique de cicatrice post-Mammotome pour le repérage préopératoire des foyers de microcalcifications mammaires.

PURPOSE: We attempted to find ultrasound scar subsequent to vacuum assisted breast biopsy (Mammotome system) previously performed, and to enhance its value for preoperative localization. MATERIALS AND METHODS: Our study included 34 females requiring needle localization prior to surgery. They previously had Mammotome core biopsies for clustered microcalcifications. US examination was systematically performed before insertion of the metallic marker, in order to detect a scar. Identification of the scar allowed ultrasonographic guided localization. The accuracy was correlated with histologic findings. RESULTS: Ultrasonography detected a scar in 21 of the 34 patients (63%). Among all these cases, a perfect correlation could be established between ultrasound target and histologic scar revealed by microscopic examination. CONCLUSION: Ultrasound detection of scar allows ultrasonographic guidance and can therefore be the only alternative in cases of absence or displacement of the marker clip.

Endocan is a novel chondroitin sulfate/dermatan sulfate proteoglycan that promotes hepatocyte growth factor/scatter factor mitogenic activity.

Proteoglycans that modulate the activities of growth factors, chemokines, and coagulation factors regulate in turn the vascular endothelium with respect to processes such as inflammation, hemostasis, and angiogenesis. Endothelial cell-specific molecule-1 is mainly expressed by endothelial cells and regulated by pro-inflammatory cytokines (Lassalle, P., Molet, S., Janin, A., Heyden, J. V., Tavernier, J., Fiers, W., Devos, R., and Tonnel, A. B. (1996) J. Biol. Chem. 271, 20458-20464). We demonstrate that this molecule is secreted as a soluble dermatan sulfate (DS) proteoglycan. This proteoglycan represents the major form either secreted by cell lines or circulating in the human bloodstream. Because this proteoglycan is specifically secreted by endothelial cells, we propose to name it endocan. The glycosaminoglycan component of endocan consists of a single DS chain covalently attached to serine 137. Endocan dose-dependently increased the hepatocyte growth factor/scatter factor (HGF/SF)-mediated proliferation of human embryonic kidney cells, whereas the nonglycanated form of endocan did not. Moreover, DS chains purified from endocan mimicked the endocan-mediated increase of cell proliferation in the presence of HGF/SF. Overall, our results demonstrate that endocan is a novel soluble dermatan sulfate proteoglycan produced by endothelial cells. Endocan regulates HGF/SF-mediated mitogenic activity and may support the function of HGF/SF not only in embryogenesis and tissue repair after injury but also in tumor progression.

Studies of acceptor site specificities for three members of UDP-GalNAc:N-acetylgalactosaminyltransferases by using a synthetic peptide mimicking the tandem repeat of MUC5AC.

The acceptor specificity of three major isoforms of UDP-GalNAc:polypeptide N-acetylgalactosaminyltranferases (murine recombinant proteins GaNTase-T1, -T2 and -T3) was investigated using the synthetic peptide (GTTPSPVPTTSTTSAP) containing clusters of threonine residues mimicking the mucin tandem repeat unit of MUC5AC. The O-glycosylated products obtained after in vitro reactions were fractionated by capillary electrophoresis and the purified glycopeptides were characterized by MALDI mass spectrometry (number of O-GalNAc residues) and by Edman degradation (site location). A maximum of three GalNAc residues was transferred into the MUC5AC motif peptide and the preferential order of incorporation for each GaNTase isoform was determined. Our results suggest that clusters of threonine appear to be essential for site recognition of peptide backbone by the ubiquitous GaNTases and also support the notion that the different GaNTase isoforms with varying substrate specificities are involved in a hierarchical order of O-glycosylation processing of the mucin-type O-glycoproteins.

Heterozygous M3Mmalton alpha1-antitrypsin deficiency associated with end-stage liver disease: case report and review.

Alpha1-antitrypsin (alpha1AT) deficiency is an autosomal recessive disorder that can cause pulmonary emphysema and liver disease. We report here the case of a 59-year-old woman who was admitted to hospital for evaluation of jaundice. She had no history of hepatitis or childhood liver disease. She had never received a blood transfusion, nor had she abused drugs or alcohol. Transjugular liver biopsy was then performed and revealed a micronodular cirrhosis. Ten months later, because of persistent liver cell failure and ascites, she underwent an orthotopic liver transplantation. Investigation of alpha1AT system in the proband revealed a substantial decrease in serum alpha1AT associated with a low elastase inhibitory capacity. The Pi phenotype revealed a PiM-like profile. Sequencing of exons 1-5 demonstrated the presence of the M3 allele. Moreover, a triple nucleotide deletion was detected in exon 2 of one allele. This caused an "in-phase" frameshift, coding for a protein deficient in a single Phe residue, which corresponded to the Mmalton variant. After liver biopsy, periodic acid-Schiff-positive acidophilic bodies resistant to diastase digestion were observed in the cytoplasm of hepatocytes. These results demonstrated that our patient had a heterozygous M3Mmalton alpha1AT genotype related to a deficiency phenotype. This observation is the first of a patient with heterozygous Mmalton genotype associated with an alpha1AT deficiency that induced severe liver disease requiring orthotopic liver transplantation.

Glycopeptide N-acetylgalactosaminyltransferase specificities for O-glycosylated sites on MUC5AC mucin motif peptides.

The recombinant proteins of the two novel UDP-N-acetylgalactosamine (GalNAc) glycopeptide:N-acetylgalactosaminyltransferases (designated gpGaNTase-T7 and gpGaNTase-T9) were assayed with O-glycosylated products obtained from the prior action of the ubiquitous transferases (GaNTase-T1 and GaNTase-T2) towards MUC5AC mucin motif peptides (GTTPSPVPTTSTTSAP and peptides with single amino acid substitutions, GTTPSAVPTTSTTSVP and GTTPSPVPTTSITSVP, that are a reflection of mucin molecule polymorphism). gpGaNTase-T9 is known to be expressed differentially and more abundantly than gpGaNTase-T7 in some tissues; the results of in vitro glycosylation also indicates a difference in acceptor substrate specificities between the gpGaNTase isoforms. With the use of capillary electrophoresis, MS and Edman degradation, our study suggests that, in the O-glycosylation of mucin-type proteins, approach and recognition signalling by gpGaNTase-T7 and gpGaNTase-T9 depend largely on the peptide's primary structure (for example the presence of multiple clusters of hydroxy amino acids and the number of GalNAc residues attached to the peptide backbone). O-glycosylation in terms of sites of attachment seems to be less random than previously described and, if sequential reactions are ordered throughout the Golgi stack, the complete O-glycosylation of the mucin molecules seems to be finely tuned to respond to specific damage to, or attack on, epithelia.

Cloning and characterization of a ninth member of the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase family, ppGaNTase-T9.

We have cloned, expressed and characterized the gene encoding a ninth member of the mammalian UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGaNTase) family, termed ppGaNTase-T9. This type II membrane protein consists of a 9-amino acid N-terminal cytoplasmic region, a 20-amino acid hydrophobic/transmembrane region, a 94-amino acid stem region, and a 480-amino acid conserved region. Northern blot analysis revealed that the gene encoding this enzyme is expressed in a broadly distributed manner across many adult tissues. Significant levels of 5- and 4.2-kilobase transcripts were found in rat sublingual gland, testis, small intestine, colon, and ovary, with lesser amounts in heart, brain, spleen, lung, stomach, cervix, and uterus. In situ hybridization to mouse embryos (embryonic day 14.5) revealed significant hybridization in the developing mandible, maxilla, intestine, and mesencephalic ventricle. Constructs expressing this gene transiently in COS7 cells resulted in no detectable transferase activity in vitro against a panel of unmodified peptides, including MUC5AC (GTTPSPVPTTSTTSAP) and EA2 (PTTDSTTPAPTTK). However, when incubated with MUC5AC and EA2 glycopeptides (obtained by the prior action of ppGaNTase-T1), additional incorporation of GalNAc was achieved, resulting in new hydroxyamino acid modification. The activity of this glycopeptide transferase is distinguished from that of ppGaNTase-T7 in that it forms a tetra-glycopeptide species from the MUC5AC tri-glycopeptide substrate, whereas ppGaNTase-T7 forms a hexa-glycopeptide species. This isoform thus represents the second example of a glycopeptide transferase and is distinct from the previously identified form in enzymatic activity as well as expression in embryonic and adult tissues. These findings lend further support to the existence of a hierarchical network of differential enzymatic activity within the diversely regulated ppGaNTase family, which may play a role in the various processes governing development.

Simple gas chromatography analysis of faecal butyrate: application to patients at risk of pouchitis.

In spite of the fact that pouchitis is the most frequently occurring and troublesome complication found in patients treated by ileo-anal anastomosis for ulcerative colitis, no biological marker currently exists to monitor the outcome of the disease. Since it has been noted faecal butyrate is reduced in patients with pouchitis, we developed a simple gas chromatography method to quantify butyrate in faecal water. This test is based on diethyl ether extraction with the use of methacrylic acid as an internal standard. We demonstrated that butyrate was effectively measured when this technique was applied to eleven patients with ileal-pouch anal anastomosis within the first year after the closure of their ileostomy. We also observed a noticeable reduction in the concentration of butyrate in patients who went on to develop a pouchitis.

Developmental mucin gene expression in the gastroduodenal tract and accessory digestive glands. II. Duodenum and liver, gallbladder, and pancreas.

Studies were undertaken to provide information regarding cell-specific expression of mucin genes and their relation to developmental and neoplastic patterns of epithelial cytodifferentiation. In situ hybridization was used to study mRNA expression of mucin genes in duodenum and accessory digestive glands (liver, gallbladder, pancreas) of 13 human embryos and fetuses (6. 5-27 weeks' gestation), comparing these with normal and neoplastic adult tissues. These investigations demonstrated that the pattern of mucin gene expression in fetal duodenum reiterated the patterns we observed during gastric and intestinal ontogenesis, with MUC2 and MUC3 expression in the surface epithelium and MUC6 expression associated with the development of Brünner's glands. In embryonic liver, MUC3 was already expressed at 6.5 weeks of gestation in hepatoblasts. As in adults, MUC1, MUC2, MUC3, MUC5AC, MUC5B, and MUC6 were expressed in fetal gallbladder, whereas MUC4 was not. In contrast, MUC4 was strongly expressed in gallbladder adenocarcinomas. MUC5B and MUC6 were expressed in fetal pancreas, from 12 weeks and 26 weeks of gestation, respectively. Surprisingly, MUC3 which is strongly expressed in adult pancreas, was not detected in developmental pancreas. Taken together, these data show complex spatio-temporal regulation of the mucin genes and suggest a possible regulatory role for mucin gene products in gastroduodenal epithelial cell differentiation.

Mucin gene expression and cell differentiation in human normal, premalignant and malignant esophagus.

Esophageal carcinoma includes squamous cell carcinoma and Barrett's adenocarcinoma. The latter usually develops from a premalignant lesion named Barrett's esophagus. MUC genes are known to be specifically expressed in the normal, premalignant and malignant epithelia of various tissues. The aim of this study was to establish the pattern of MUC gene expression in the esophageal mucosa under normal conditions, and under pathological conditions such as squamous cell carcinoma, Barrett's esophagus and adenocarcinoma. Samples of esophageal control mucosa, metaplastic and malignant tissues were obtained from 40 patients undergoing esophagectomy for squamous cell carcinoma (n = 17), or Barrett's esophagus with adenocarcinoma (n = 23). In situ hybridization and northern blot were used with probes specific for the MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6 and MUC7 genes to assess their expression in these samples. Submucosal glands of control esophageal mucosa expressed MUC5B, whereas MUC1 and MUC4 were found in both control epithelium and squamous cell carcinoma. MUC4 expression correlated with squamous cell differentiation. Barrett's adenocarcinoma exhibited various patterns of MUC gene expression, the strongest being in the well-differentiated mucinous adenocarcinomas. Barrett's metaplasia was also associated with a specific MUC gene expression pattern, since the gastric apomucin mRNAs, MUC5AC and MUC6, were expressed in gastric metaplasia, and the intestinal apomucin mRNAs, MUC3, MUC4 and mostly MUC2, in intestinal metaplasia. Residual expression of gastric apomucin mRNAs was found in intestinal metaplasia. From these results, we conclude that MUC genes can be considered reliable phenotypic markers of the esophageal cell differentiation, thus providing new insight into the development of Barrett's esophagus.

Oxidative markers in diabetic ketoacidosis.

UNLABELLED: Oxidative stress has been implicated in the pathogenesis of the chronic complications of diabetes mellitus but little is known in diabetic ketoacidosis (DKA). The aim of this work was to determine whether lipid peroxidation, as assessed by measuring malondialdehyde (MDA, a prooxidant) and antioxidant status (TAS, an index of antioxidant defenses), is modified in DKA, and also whether any observed abnormalities were related to metabolic disturbances. METHODS: four groups of patients were studied, comprising 19 patients with DKA, massive ketonuria and plasma standard bicarbonate levels below 16 mmol/l (group 1); 20 patients with poorly controlled diabetes, glycated hemoglobin (HbA1c) above 8% and plasma bicarbonate levels above 16 mmol/l (group 2); 11 patients with well-controlled diabetes and HbA1c below 8% (group 3); and 10 non-diabetic, non-obese control subjects (group 4). Metabolic parameters, MDA levels and TAS were assessed in the plasma of the four groups of subjects. RESULTS: mean plasma MDA and TAS values were significantly different among the four groups (respectively p < 0.001 and p < 0.01). Mean plasma MDA value was significantly higher in group 1 than in group 3 (p < 0.02) and group 4 (p < 0.001) but was not different from that in group 2. Mean plasma MDA value in group 2 was significantly lower than that in group 4 (p = 0.002). Mean plasma TAS value in group 1 was significantly lower than in groups 3 (p < 0.002) and 4 (p < 0.05). Mean plasma TAS value was significantly lower in group 2 than in group 4 (p<0.05). Plasma MDA values in the diabetic patients (groups 1+2+3) were not related to any clinical characteristics (BMI, age, duration of the disease) or metabolic parameters (glycemia, HbA1c bicarbonates, blood urea nitrogen, phosphatemia, lipids), while plasma TAS values correlated negatively with glycemia, osmolality and HbA1c. A significant relationship was also found between TAS and HbA1c in group 1 (p < 0.05) and between MDA and HbA1c in group 3 (p < 0.05). Correlations were also found between TAS and phosphatemia in group 1 (p < 0.01) and between MDA and phosphatemia in group 2 (p < 0.01). A positive relationship between MDA and cholesterol levels was found in group 1 (p < 0.01). In conclusion, MDA values are increased and TAS values decreased in DKA and poorly controlled diabetes, and tend to correlate more with markers of diabetic imbalance than with markers of acute metabolic disturbances of DKA.

Acute inflammatory intestinal vascular lesions and in situ abnormalities of the plasminogen activation system in Crohn's disease.

OBJECTIVES: The distribution of the intestinal vascular lesions and their relation with the fibrinolysis process are poorly known in Crohn's disease (CD). The mediators of the plasminogen activator system, namely urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1), are a key complex involved in fibrinolysis. The aims of this study were: (1) to further define vascular lesions and their distribution in the intestine; and (2) to study concomitantly the qualitative in situ expression and the levels of u-PA, t-PA and PAI-1 in the ileum of patients with CD. PATIENTS AND METHODS: Histological, immunohistochemical and ultrastructural studies of vascular lesions in the resected ileum of 27 patients with CD were performed and compared with 36 control patients. Levels of u-PA, t-PA and PAI-1 measured by ELISA methods were compared in healthy and inflamed ileal tissues of 17 patients with CD. RESULTS: Acute vascular lesions involving mainly serosal venules and capillaries were present in 63% of patients with CD vs 3/36 controls and were associated with PAI-1 expression. They were prominent on the mesenteric border beneath macroscopically normal mucosa. In contrast, chronic vascular lesions were present in all layers beneath mucosal ulcerations, where a significant increase of PAI-1 levels was found. CONCLUSIONS: These results suggest that vascular involvement associated with abnormalities of PAI-1 expression is an early and widespread event in CD. Their prominence on the mesenteric border might explain the characteristic location of CD ulceration along the mesenteric margin.

Characterization of a UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase that displays glycopeptide N-acetylgalactosaminyltransferase activity.

We report the cloning, expression, and characterization of a novel member of the mammalian UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGaNTase) family that transfers GalNAc to a GalNAc-containing glycopeptide. Northern blot analysis revealed that the gene encoding this enzyme, termed ppGaNTase-T6, is expressed in a highly tissue-specific manner. Significant levels of transcript were found in rat and mouse sublingual gland, stomach, small intestine, and colon; trace amounts were seen in the ovary, cervix, and uterus. Recombinant constructs were expressed transiently in COS7 cells but demonstrated no transferase activity in vitro against a panel of unmodified peptides, including GTTPSPVPTTSTTSAP (MUC5AC). However, when incubated with the total glycosylated products obtained by action of ppGaNTase-T1 on MUC5AC (mainly GTT(GalNAc)PSPVPTTSTT(GalNAc)SAP), additional incorporation of GalNAc was achieved, resulting in new hydroxyamino acids being modified. The MUC5AC glycopeptide failed to serve as a substrate for ppGaNTase-T6 after modification of the GalNAc residues by periodate oxidation and sodium borohydride reduction, indicating a requirement for the presence of intact GalNAc. This suggests that O-glycosylation of multisite substrates may proceed in a specific hierarchical manner and underscores the potential complexity of the processes that regulate O-glycosylation.

Type 1 multiple endocrine neoplasia (MEN1): contribution of genetic analysis to the screening and follow-up of a large French kindred.

OBJECTIVE: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal genetic disorder, the clinical phenotype of which includes tumours of the parathyroids and/or anterior pituitary and/or endocrine pancreas. The genetic defect has been mapped to the chromosome 11q13 and the MEN1 gene has been recently identified, thus allowing genetic screening in affected kindreds. The aim of this study was to establish the usefulness of genetic screening in the follow-up of a large MEN1 kindred. PATIENTS: We describe a large kindred of 91 members, of whom 56 had clinical, biochemical and genetic screening. Twenty eight of them have been tested annually for the last 5 years. RESULTS: Although the precise mutation is still undetermined in this kindred, genotypic determination confirmed linkage with the MEN1 gene in affected members and excluded 28 members from annual testing. By drawing our attention to susceptible subjects, genetic screening improved the evaluation of age-related penetrance of the disease in the 3 generations from this kindred. For instance, annual screening showed conversion from unaffected to affected phenotype in 4 subjects aged 14, 14, 15, and 17 years. Moreover, genetics helped us to evaluate the specificity of clinical or biochemical markers, and thus to discard useless investigations. So far however, the genetics have not helped to explain the phenotypic heterogeneity and particularly low incidence of pancreatic tumours in this kindred. CONCLUSION: Genetic screening is very useful in detecting high risk individuals for MEN 1, since it avoids time-consuming and expensive investigations in non-affected subjects. By providing better understanding of the age-related penetrance of this syndrome, it improves the efficiency of screening. Genetic studies allow differentiation between clinical and biochemical features that are useful in follow-up and other confusing or unhelpful parameters.

Changes in serum amylase, lipase and leukocyte elastase during diabetic ketoacidosis and poorly controlled diabetes.

Diabetic ketoacidosis (DKA) is frequently associated with pancreatic enzyme abnormalities. In order to determine the main factors that lead to this increase, serum total amylase (TA), pancreatic amylase (PA), lipase (L) and leukocyte elastase (LE), an early predictor of acute pancreatitis, were measured in four groups of patients on admission. Group 1 consisted of 52 patients with DKA (age: 41.9 +/- 19.2 years; blood glucose (Glc): 27.4 +/- 11.5 mmol/L; pH: 7.20 +/- 0.16; plasma bicarbonate: 10.5 +/- 6.2 mmol/L; blood urea nitrogen (BUN): 0.60 +/- 0.44 g/L; HbA(1C): 12.5% +/- 2.8%). Group 2 consisted of 90 patients with poorly controlled non-ketotic diabetes (age: 53.4 +/- 16.0; Glc: 14.3 +/- 0.6; HCO(3)(-): 26.6 +/- 3.2; BUN: 0.38 +/- 0.20; HbA(1C): 11.3 +/- 2.1). Group 3 consisted of 22 patients with well-controlled diabetes (age: 53.7 +/- 12.8; Glc: 10. 1 +/- 5.2; HCO(3)(-): 27.4 +/- 3.8; BUN: 0.36 +/- 0.19; HbA(1C): 6.8 +/- 0.8). Group 4 (controls) comprised 27 non-diabetic patients (age: 46.0 +/- 15.0; Glc: 4.9 +/- 0.5; HCO(3)(-): 28.4 +/- 2.5; BUN: 0.30 +/- 0.16; HbA(1C): 5.2 +/- 0.7) (means +/- SD). Increased enzyme activities were more frequent in group 1 (TA: 30.7; PA: 27.0; L: 36.5; LE: 73%) than in groups 2 (TA: 8.9; PA: 7.1; L: 8.9; LE: 45. 5%), 3 (TA: 13.6; PA: 9.0; L: 18.1; LE: 31.8%) and 4 (TA: 7.0; PA: 3. 0; L: 0.0; LE: 29.6%). Mean serum enzyme activities were significantly different in the 4 groups (ANOVA, P < 0.01) and were higher in group 1 than in groups 2, 3 and 4 (Student's t-test; group 1 vs 2 or 3 or 4: P < 0.001). In groups 1 + 2 + 3 + 4 (all patients), the four enzymes correlated with one another and also with Glc, BUN and HCO(3)(-) (P < 0.001). In group 1, TA correlated negatively with HCO(3)(-) (P < 0.001) and pH (P < 0.05); PA and L correlated positively with Glc and BUN (P < 0.01) and negatively with HCO(3)(-) (respectively, p < 0.01 and 0.05). PA correlated positively with pH (P < 0.01); LE correlated with Glc (P < 0.05) and BUN (P < 0.01). In conclusion, this study suggests that the serum levels of pancreatic enzymes increase with the degree of diabetic disequilibrium, and mainly correlate with metabolic factors such as hyperglycaemia, dehydration and acidosis. Increased pancreatic enzyme activities in patients with DKA, even in combination with abdominal pain, should not be diagnosed as acute pancreatitis; this could be important, particularly for younger clinicians.

Capillary zone electrophoresis and MALDI-mass spectrometry for the monitoring of in vitro O-glycosylation of a threonine/serine-rich MUC5AC hexadecapeptide.

The in vitro N-acetylgalactosaminylation by human gastric UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases was assessed using the peptide motif GTTPSPVPTTSTTSAP, which is found naturally in the tandem repeat domains of the apomucin encoded by the gene MUC5AC. This peptide appeared to be an excellent tool for obtaining an insight into the extensive O-glycosylation processes of apomucins. Up to six N-acetylgalactosamines were added and the given glycopeptide species were well separated by capillary zone electrophoresis. Moreover, the degree of glycosylation (number of monosaccharide O-linked attachments) could be determined by MALDI-mass spectrometry without prior separation. Using different incubation times, we evidenced the accumulation of various glycopeptides, suggesting that the total glycosylation of an apomucin-peptide requires orderly N-acetylgalactosaminylation processing. This information was completed by experimental data showing that N-acetylgalactosaminylated octapeptides (the peptide backbones of which are part of GTTPSPVPTTSTTSAP) were able to selectively inhibit some N-acetylgalactosaminyltransferases. Our results suggest that this inhibition may influence the quality of the intermediate products appearing during the in vitro O-glycosylation process.