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Biomedical subjects

C Vermeulen

Publications and source records attributed to C Vermeulen.

At least 19 recordsLinked to original sources
PubMed2006

Occurrence of polyfunctional thiols in fresh lager beers.

Polyfunctional thiols are known to have a strong impact on the overall aroma of many fermented foods. Surprisingly, very little data is available on their occurrence in beer. A specific extraction with p-hydroxymercuribenzoic acid was performed on four different fresh light-protected lager beers. gas chromatography-olfactometry, gas chromatography-mass spectrometry, and gas chromatography-pulsed-flame photometer detector analyses of the extracts revealed the presence of more than 10 polyfunctional thiols. All of them were absent from wort, suggesting a key role of the H(2)S excreted by yeasts. 3-Methyl-2-buten-1-thiol, 2-mercapto-3-methylbutanol, 3-mercapto-3-methylbutanol seem to be created from hop allylic alcohols via four different mechanisms: nucleophilic substitution, addition-elimination, and radical anti-Markovnikov or electrophilic Markovnikov additions. 1,4 Addition of hydrogen sulfide to wort alpha,beta-unsaturated aldehydes or ketones may explain the synthesis of 1-mercapto-3-pentanol, 3-mercaptohexanol, and 4-mercapto-4-methyl-2-pentanone through fermentation. Finally, 2-mercaptoethanol, 3-mercaptopropanol, and their corresponding acetates may derive from Ehrlich degradation of sulfur amino acids, while 2-methyl-3-furanthiol should be logically issued from Maillard reactions.

Beer↗
PubMed2003

[The clinical diagnosis 'wound botulism' in an injecting drug addict].

A 38-year-old subcutaneous injecting heroin addict had subacute blurred vision, dysarthria and dysphagia. The next day she could not swallow or speak and developed weakness of all limbs and respiratory failure. Electromyography showed abnormalities compatible with a presynaptic neuromuscular transmission deficit, which supported the diagnosis of botulism. The point of entry was probably a skin abscess due to injections. Treatment with antitoxin and antibiotics resulted in a favourable recovery. Wound botulism is caused by local production of toxin by Clostridium botulinum after wound infection. Although it is a rare variant of botulism, it is increasingly being reported in drug users who inject subcutaneously.

Adult↗
PubMed2003

[Chronic urticaria, thyroiditis and autologous serum test].

INTRODUCTION: The autoimmune nature of certain forms of chronic urticaria remains debatable. Aim of the study. To find a correlation in terms of autoimmune pattern between chronic urticaria and thyroiditis using the autologous serum test and the search for anti-thyroid antibodies. PATIENTS AND METHODS: Study in a single center of 59 patients having consulted for urticaria that had progressed for more than six weeks and without precise etiology. An autologous serum test was conducted and anti-thyroid autoantibodies were searched for in the serum stored after the test. RESULTS: Out of 59 patients, 51 had an interpretable autologous serum test and 57 underwent research for anti-thyroid antibodies. Twelve patients out 57 (21 p.cent) exhibited one or more types of positive (n=10) or borderline (n=2) anti-thyroid antibodies, and eight out of 12 (66.6 p.cent) had a known thyroid disease before the onset of urticaria. The systematic blood test permitted the discovery of 4 cases of unknown anti-thyroid antibodies. The symptoms regressed in two of these patients without any specific treatment, one patient was treated with L thyroxin for hyperthyroidism without any improvement in the symptoms and one other patient had normal thyroid function. Among these 12 patients, 11 underwent autologous serum tests, but only 3 of them exhibited clearly positive results and one was doubtful. CONCLUSIONS: Within the limits of this study, we found a 21 p.cent rate of patients with chronic urticaria exhibiting one or more anti-thyroid antibodies. The positivity of the autologous serum test does not appear to be related with autoimmune thyroid disorders.

Adolescent↗
PubMed2002

[Responsibility of food in exercise-induced anaphylaxis: 7 cases].

INTRODUCTION: Exercise induced-anaphylaxis is a rare allergic disease. In most cases, the ingestion of a specific food within a maximum of 4 hours preceding physical activity is necessary to develop the anaphylactic reaction. CASE-REPORTS: We report 7 cases of food-dependant exercise induced-anaphylaxis. The responsible foods were wheat (2 cases), corn, barley, shrimp, apple, paprika and mustard. The discovery of the food allergen and its systematic eviction 4 hours before the beginning of a physical effort led to the disappearance of clinical symptoms in all cases. DISCUSSION: The role of food in exercise-induced-anaphylaxis is essential. The food in cause varies but our study confirms the predominant role of cereal food which is a less sensitizer in adults, except in a context of effort. The responsibility of this type of food consumed daily can explain partially the frequent delay before diagnosis of this allergic disease.

Adolescent↗
PubMed2001

Combinatorial synthesis and sensorial properties of polyfunctional thiols.

Over the past few years, polyfunctional thiols present as trace components have been found to play a major role in many food flavors, due to their exceptionally low odor thresholds. Unfortunately, their presence in minute concentration (in ng/kg to a few microg/kg) and their high reactivity make it very difficult to extract and identify them. Furthermore, most of them are not yet commercially available. The aim of this work was to characterize the chromatographic and sensorial properties of 10 synthetic mercaptoketones and mercaptoalcohols. Combinatorial chemistry proved to be a very useful way to synthesize them rapidly. Sulfur-selective sulfur chemiluminescence detection chromatograms coupled with mass spectroscopy enabled the target compounds to be identified. Flavor profiles and best estimate gas chromatography lowest amount detected by sniffing (BE-GC-LOADS) values were further determined by GC-olfactometry. As expected, new, exceptionally odorant molecules (BE-GC-LOADS < 0.1 ng) were revealed by this unusual approach.

Chromatography, Gas↗
PubMed2001

[Allergy in women].

Allergy affects without distinction both sexes. Nevertheless some allergens are responsible more frequently for contact dermatitis in females. The components of cosmetics and in first fragrance are indeed responsible for numerous contact dermatitis because of their increasing use. Nickel allergy is the most frequent contact allergy in women with a rate of 20-40% of female population and only 3-5% of male population. Specific female allergies such as allergy to seminal liquid or autoimmune progesterone dermatitis are on the other hand exceptional.

Cosmetics↗
PubMed2000

[Joint manifestations related to Clostridium difficile].

BACKGROUND: Reactional joint disease subsequent to digestive tract infections have been well studied for Salmonella, Shigella, Yersinia and Campylobacter. Association with HLA B27 is well documented. A review of the literature since 1976 disclosed 23 cases of articular and extra-articular inflammatory reactions following pseudomembranous Clostridium difficile infection. CASE REPORT: We describe 2 new cases which followed a favorable course. This is the usual outcome although inflammatory manifestations may persist or relapse. DISCUSSION: The pathophysiological interest of this condition lies in the pathogenic potential of Clostridium difficile which appears to be directly related to toxin production. This would suggest an immune mechanism rather than pure infection.

Adult↗
PubMed1999

Pelvic floor rehabilitation in multiple sclerosis.

Although primarily used for treatment of stress incontinence, pelvic floor rehabilitation has been reported to have some value in the treatment of detrusor instability and urgency. In neurogenic bladder dysfunction due to Multiple Sclerosis, many authors have suggested the possible use of pelvic floor rehabilitation as a treatment modality. Therefore, we designed an open prospective trial to look at the possible role of pelvic floor rehabilitation in voiding dysfunction due to MS, concentrating upon the clinical and neurological parameters in relation to the outcome. A new scoring system for pelvic floor dysfunction is introduced. Thirty female patients were evaluated. In 25, the strength of the pelvic floor was significantly improved after one month (p < 0.001). In all patients but one the endurance score improved significantly (p < 0.001) as did the exhaustibility score (p = 0.01). The relaxation score on the other hand did not show any significant evolution despite intensive training. Cystometric findings after one month did not significantly differ from the initial cystometric findings. There was a significant increase in the mean functional bladder capacity as read from the voiding charts from 173.8 cc +/- 53.9 cc to 208.5 cc +/- 57.6 cc (p = 0.005). Also the mean urinary frequency decreased significantly from 12.7 +/- 3.6 to 9.1 +/- 2.6 (p < 0.01) as did the mean number of daily incontinent episodes from 2.8 +/- 1.3 to 1.5 +/- 1.5 (p < 0.01). Pelvic floor rehabiltation has a place in the treatment of MS patients with a low Kurtzke score and without pelvic floor spasticity.

Adult↗
PubMed1998

Clinical assessment of pelvic floor dysfunction in multiple sclerosis: urodynamic and neurological correlates.

We present a study on the clinical assessment of pelvic floor dysfunction in 30 female patients with proven multiple sclerosis (MS). A scoring system for pelvic floor muscle testing by digital vaginal palpation is proposed. The concept of pelvic floor spasticity in MS is introduced. The relationship of our findings with the neurological findings and urodynamic data is presented. Pelvic floor spasticity correlates well with the presence of detrusor-external sphincter dyssynergia and with more severe spinal cord disease.

Female↗
PubMed1996

The generation of SDS-stable HLA DR dimers is independent of efficient peptide binding.

MHC class II molecules can exist in two conformations which can be distinguished on the basis of their stability in SDS. The formation of SDS-stable dimers has been shown to correlate with persistent expression of antigen MHC class II-peptide complexes by murine antigen-presenting cells. HLA DR molecules contain either a Val or a Gly at position 86 of the beta chain, which is located in a conserved and prominent hydrophobic pocket in the peptide binding site. Here we show that Val86-containing DR molecules more frequently select peptides which induce the formation of SDS-stable dimers than Gly86 variants. Using analogues of the influence virus haemagglutinin epitope 307-319 we found that the replacement of the aromatic hydrophobic anchor residue (Tyr)at position 309 by amino acids with an aliphatic hydrophobic side chain resulted in the specific formation of high numbers of SDS-stable Val86-DR but not Gly86-DR dimers. These results indicate that the fit between the first anchor residue and the hydrophobic pocket around Dr beta 86 plays a critical role in the formation of SDS-stable DR dimers. Synthetic analogues of naturally processed DR-associated peptides displayed promiscuity in their capacity to bind to several DR specificities and in their ability to induce the SDS-stable conformation. However, no correlation was observed between binding capacity and the ability to induce the SDS-stable conformation. Since it has been shown that SDS stability can relate to the kinetics of peptide-MHC class II interactions, the definition of the requirements for the formation of SDS-stable HLA class II molecules may be important for the design of effective peptide-based immunomodulation protocols.

Amino Acid Sequence↗
PubMed1988

Quantitative relationship between capsular content and killing of K1-encapsulated Escherichia coli.

Since there are conflicting reports in the literature on a possible relationship between the K1 capsular polysaccharide (CP) content of Escherichia coli and its susceptibility to killing, we reexamined this issue in a strain that had a smooth lipopolysaccharide (LPS) phenotype (E. coli O18:K1:H7 Bort) and in a strain with a deep rough LPS phenotype (E412, spontaneously agglutinable: K1:H-). When cell-associated K1 capsular content was greater than 90 micrograms of K1 polysaccharide per 10(10) CFU, neither strain was lysed by 20% normal human serum. In contrast, at equivalent but lower levels of K1 CP content, E412 but not strain Bort was lysed by normal human serum. Thus, LPS phenotype is an additional surface determinant that affects bacterial susceptibility to killing. Organisms obtained from very early log phase, when cell-associated K1 CP is greatest, were significantly more virulent for mice than were bacteria harvested in stationary phase, when cell-associated K1 polysaccharide is lowest. We conclude that (i) there is a threshold level of K1 CP needed to confer protection from lysis by serum, and this is usually exceeded under standard growth conditions; (ii) at a given level of K1 CP the LPS phenotype is an important determinant of bacterial killing; and (iii) the loss of capsule at low pH may be an additional mechanism by which hosts defend against invasive infection by K1-encapsulated E. coli.

Antibodies, Bacterial↗