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Biomedical subjects

P Jacques

Publications and source records attributed to P Jacques.

At least 55 records · Page 3Linked to original sources
PubMed1996

Relation of dietary intake and serum levels of vitamin D to progression of osteoarthritis of the knee among participants in the Framingham Study.

BACKGROUND: Evidence suggests that pathophysiologic processes in bone are important determinants of outcome in osteoarthritis of the knee. Low intake and low serum levels of vitamin D may compromise favorable responses of bone to osteoarthritis, predisposing patients to progression. OBJECTIVE: To determine whether dietary intake and serum levels of vitamin D would predict the incidence and progression of osteoarthritis of the knee in participants of the Framingham Study. DESIGN: Prospective observational study. SETTING: The Framingham Study. PARTICIPANTS: Participants in the Framingham Heart Study who had knee radiography at examinations 18 (done between 1983 and 1985) and 22 (done between 1992 and 1993) and received interim assessments of vitamin D intake and serum levels. MEASUREMENTS: Intake of vitamin D and serum levels of 25-hydroxyvitamin D, calculated on the basis of dietary habits and supplement use as reported on a questionnaire, were evaluated at examination 20 (1988 to 1989). Knee radiographs were given scores for global severity of osteoarthritis, using a modification of the scale of Kellgren and Lawrence (range, 0 to 4), and for the presence of osteophytes and joint-space narrowing (range, 0 to 3). Covariates measured at examinations 18 and 20 were age, sex, body mass index, weight change, injury, physical activity, health status, bone mineral density, and energy intake. RESULTS: 556 participants (mean age at baseline +/- SD, 70.3 +/- 4.5 years) had complete assessments. Incident osteoarthritis occurred in 75 knees; progressive osteoarthritis occurred in 62 knees. Serum levels of vitamin D were modestly correlated with vitamin D intake (r = 0.24). Risk for progression increased threefold in participants in the middle and lower tertiles for both vitamin D intake (odds ratio for the lower compared with the upper tertile, 4.0 [95% Cl, 1.4 to 11.6]) and serum levels of vitamin D (odds ratio for the lower compared with the upper tertile, 2.9[Cl, 1.0 to 8.2]). Low serum levels of vitamin D also predicted loss of cartilage, as assessed by loss of joint space (odds ratio, 2.3 [Cl, 0.9 to 5.5]) and osteophyte growth (odds ratio, 3.1 [Cl, 1.3 to 7.5]). Incident osteoarthritis of the knee occurring after baseline was not consistently related to either intake or serum levels of vitamin D. CONCLUSIONS: Low intake and low serum levels of vitamin D each appear to be associated with an increased risk for progression of osteoarthritis of the knee.

Cartilage, Articular↗
PubMed1996

Do antioxidant micronutrients protect against the development and progression of knee osteoarthritis?

OBJECTIVE: Cumulative damage to tissues, mediated by reactive oxygen species, has been implicated as a pathway that leads to many of the degenerative changes associated with aging. We hypothesized that increased intake of antioxidant micronutrients might be associated with decreased rates of osteoarthritis (OA) in the knees, a common age-related disorder. METHODS: Participants in the Framingham Osteoarthritis Cohort Study underwent knee evaluations by radiography at examinations 18 (1983-1985) and 22 (1992-1993). Usual dietary intake was assessed using the Food Frequency Questionnaire, administered at examination 20 (1988-1989). Knees without OA at baseline (Kellgren and Lawrence [K&L] grade < or = 1) were classified as having incident OA if they had a K&L grade > or = 2 at followup. Knees with OA at baseline were classified as having progressive OA if their score increased by > or = 1 at followup. Knees were also classified as having cartilage loss or osteophyte growth if their maximal joint space narrowing or osteophyte growth score increased by > or = 1 (range 0-3). The association of vitamin C, beta carotene, and vitamin E intake, ranked in sex-specific tertiles, with incidence and progression of OA was compared with that of a panel of nonantioxidant vitamins, Bl, B6, niacin, and folate, using logistic regression and generalized estimation equations to adjust for correlation between fellow knees. The lowest tertile for each dietary exposure was used as the referent category. Odds ratios (OR) were adjusted for age, sex, body mass index, weight change, knee injury, physical activity, energy intake, and health status. RESULTS: Six hundred forty participants received complete assessments. Incident and progressive OA occurred in 81 and 68 knees, respectively. We found no significant association of incident OA with any nutrient. A 3-fold reduction in risk of OA progression was found for both the middle tertile (adjusted OR = 0.3, 95% confidence interval [95% CI] 0.1-0.8) and highest tertile (adjusted OR = 0.3, 95% CI 0.1-0.6) of vitamin C intake. This related predominantly to a reduced risk of cartilage loss (adjusted OR = 0.3, 95% CI 0.1-0.8). Those with high vitamin C intake also had a reduced risk of developing knee pain (adjusted OR = 0.3, 95% CI 0.1-0.8). A reduction in risk of OA progression was seen for beta carotene (adjusted OR = 0.4, 95% CI 0.2-0.9) and vitamin E intake (adjusted OR = 0.7, 95% CI 0.3-1.6), but was less consistent. No significant associations were observed for the nonantioxidant nutrients. CONCLUSION: High intake of antioxidant micronutrients, especially vitamin C, may reduce the risk of cartilage loss and disease progression in people with OA. We found no effect of antioxidant nutrients on incident OA. These preliminary findings warrant confirmation.

Aged↗
PubMed1994

Increased risk for hepatitis A among female day nursery workers in Belgium.

To assess the risk for hepatitis A virus (HAV) infection in an occupational group potentially at risk for faeco-oral contact with very young children, a prevalence study of total anti-HAV antibodies (IgG/IgM) was conducted among 591 female employees in day nurseries in Flanders, Belgium, and in a reference group of 560 healthy female blood donors, matched for age. Analysis was also performed on formally exposed persons (n = 413) versus blood donors (n = 560). The overall prevalence of HAV markers was 48.4% (95% CI: 44.2-52.5) in exposed day nursery personnel, compared with 42.9% (95% CI: 38.7-47.0) in blood donors. The age-specific prevalence rates showed a steeper rise from the age of 30 years among the exposed employees than among the blood donors, with significantly higher prevalences between 35 and 44 years of age. The discrepancies levelled off above 60 years of age. Standardization for parenthood using logistic regression did not affect the odds ratio. These results are in line with recent findings of a higher prevalence of HAV markers among groups of workers professionally exposed to small children. Appropriate measures for the protection of these groups should be taken.

Adult↗
PubMed1993

Comparison of the substrate-binding pockets of the Rous sarcoma virus and human immunodeficiency virus type 1 proteases.

A steady state kinetic analysis of the avian myeloblastosis virus/Rous sarcoma virus (AMV/RSV) and human immunodeficiency virus Type 1 (HIV-1) retroviral proteases (PRs) was carried out using a series of 40 peptide substrates that are derivatives of the AMV/RSV nucleocapsid-PR cleavage site. These peptides contain single amino acid substitutions in each of the seven positions of the minimum length substrate required by the PR for specific and efficient cleavage. These peptide substrates are distinguished by the individual enzyme subsites of the AMV/RSV and HIV-1 PRs. The molecular basis for similarities and differences of the individual subsites for both proteases is discussed using steady state kinetic data and modeling based on crystal structures.

Amino Acid Sequence↗
PubMed1993

Purification of antifungal lipopeptides by reversed-phase high-performance liquid chromatography.

A rapid procedure for the purification of antifungal lipopeptides from Bacillus subtilis, a potential agent for biocontrol of plant diseases, was tested. It consists of a solid-phase extraction on C18 gel followed by reversed-phase chromatography using a biocompatible PepRPC HR 5/5 column with a pharmacia fast protein liquid chromatographic system. This is a very effective method for isolating and fractionating iturin A and surfactin, two lipopeptides of different nature, co-produced by Bacillus subtilis strain S499. The presence of homologous lipopeptides was easily detected.

Amino Acid Sequence↗
PubMed1993

Back pain and its correlates among workers in family care.

In order to assess the prevalence of back pain problems among family care workers, and the association of back pain with selected variables, a cross-sectional survey among the 4723 employees of the largest Flemish organization for family care was conducted. A self-administered questionnaire comparable to the standardized Nordic questionnaire on musculoskeletal symptoms was distributed to all employees of the organization. The response rate was 90 per cent (n = 4256) and the study population was almost uniformly composed of females (99.8 per cent). The period prevalence (12 months) amounted to 63 per cent (95 per cent CI: 61.7-64.6) and the point prevalence to 18 per cent (95 per cent CI: 16.5-18.8). Among the respondents suffering from back pain during the past year, 72 per cent suffered from repeated episodes of pain. In 82 per cent low back pain was involved. Twenty-nine per cent of the complaints interrupted their work during the past year, yielding a total number of 23,396 days of sick leave. The mean sick leave for back pain was 36 days and the median 15 days. The frequency of back pain was found to vary according to the regional departments to which the employees belonged, some sections experiencing up to 36 per cent higher period prevalences than the units with the lowest figures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Pharmacoeconomics of immunisation: a review.

The effects of immunisation programmes that have existed for several decades in developed countries are demonstrated by the decrease and even eradication of smallpox, poliomyelitis, measles, mumps and hepatitis B. Cost, health policy and spontaneous evolution in the incidence of communicable diseases have a decisive influence on the use of a vaccine. Investment in vaccination policy has to be encouraged to maintain this progress made in the control of infectious diseases and to meet new challenges. Studies re-evaluating ongoing immunisation programmes are scarce. Nevertheless, it can be concluded that for vaccination against hepatitis B in professionally exposed at-risk populations, arguments for positive returns are consistent. The same holds for vaccination against S. pneumoniae and for influenza virus in the elderly. The results of the economic evaluation of revaccination against measles, when insufficient coverage exists, are inconclusive. Universal vaccination of children against Haemophilus influenzae type b (Hib) and of children of hepatitis B-positive mothers against hepatitis may require costs to be paid in order to gain extra health benefits.

Costs and Cost Analysis↗
PubMed1992

Chronic idiopathic urticaria: profiles of skin mast cell histamine release during active disease and remission.

Chronic idiopathic urticaria (CIU) is characterized by the increased releasability of histamine by mast cells in normal-appearing skin. In active CIU, this abnormality is consistently present. To determine if this finding subsides when the disease goes into remission phase, we analyzed the histamine secretion in patients with CIU in remission (CIUR) compared with that of patients with CIU and in normal control (NC) subjects, with the skin-chamber technique. The profiles of histamine release in sites challenged with compound 48/80 were significantly different in the groups with CIU and CIUR. Furthermore, patients with CIUR did not differ from NC subjects in terms of histamine releasability under compound 48/80 stimulation (p greater than 0.1). These data suggest that the state of excessive skin mast cell sensitivity is a reversible and transient phenomenon in CIU disease.

Analysis of Variance↗
PubMed1992

Stability, frequency and multiplicity of transposon insertions in the pyoverdine region in the chromosomes of different fluorescent pseudomonads.

Tn5 mutagenesis of different fluorescent pseudomonads was achieved by conjugational transfer of the suicide vector pSUP 10141. Pyoverdine negative (Pvd-) mutants were detected by the absence of fluorescence on King's B medium and by their inability to grow in the presence of the iron chelator EDDHA [ethylenediamine di(o-hydroxyphenylacetic acid)]. In P. fluorescens ATCC 17400 and three rhizosphere isolates (one P. putida and two P. fluorescens), the percentage of Pvd- mutants ranged between 0 and 0.54%. In a P. chlororaphis rhizosphere isolate, this percentage was higher (4%). In these mutants both of the Tn5 antibiotic resistances (Km and Tc) were stable and the transposon could be detected by hybridization. In Pvd- mutants of P. fluorescens ATCC 17400, the transposon was found to be inserted twice in the chromosome while single insertions were detected in the DNA of other, randomly tested mutants. In P. aeruginosa PAO1, where 13.1% of the mutants were Pvd-, both antibiotic resistances were rapidly lost and accordingly no transposon insertion could be detected by hybridization. However, the Pvd- phenotype was generally stable in these mutants. The plasmid pNK862 containing a mini-Tn10 transposon was introduced by electroporation into P. aeruginosa PAO1 and Kmr mutants were recovered, 89% of which were Pvd- and confirmed to be P. aeruginosa by PCR amplification of the P. aeruginosa lipoprotein gene. The mini-Tn10 insertions were also found to be unstable in PAO1.

Blotting, Southern↗
PubMed1992

m-Sulfonate benzene diazonium chloride: a powerful affinity label for the gamma-aminobutyric acid binding site from rat brain.

m-Sulfonate benzene diazonium chloride (MSBD) was used to affinity-label the gamma-aminobutyric acid (GABA) binding site from rat brain membranes. To assess the irreversibility of the labeling reaction, we used an efficient ligand dissociation procedure combined to a rapid [3H]muscimol binding assay, both steps being performed on filter-adsorbed membranes. Inactivation of specific [3H]-muscimol binding sites by MSBD and its prevention by GABA were both time- and concentration-dependent. The time course of MSBD labeling was shortened as the pH of the incubation medium was increased from 6.2 to 8. These data suggest that MSBD can efficiently label the GABA binding site through alkylation of a residue having an apparent dissociation constant around neutrality.

Affinity Labels↗
PubMed1991

The Enterococcus hirae R40 penicillin-binding protein 5 and the methicillin-resistant Staphylococcus aureus penicillin-binding protein 2' are similar.

The penicillin-resistant Enterococcus hirae R40 has a typical profile of membrane-bound penicillin-binding proteins (PBPs) except that the 71 kDa PBP5 of low penicillin affinity represents about 50% of all the PBPs present. Water-soluble tryptic-digest peptides were selectively produced from PBP5, their N-terminal regions were sequenced and synthetic oligonucleotides were used as primers to generate a 476 bp DNA fragment by polymerase chain reaction. On the basis of these data, the PBP5-encoding gene was cloned in Escherichia coli by using pBR322 as vector. The gene, included in a 7.1 kb insert, had the information for a 678-amino acid-residue protein. PBP5 shows similarity, in the primary structure, with the high-molecular-mass PBPs of class B. In particular, amino acid alignment of the enterococcal PBP5 and the methicillin-resistant staphylococcal PBP2' generates scores that are 30, for the N-terminal domains, and 53, for the C-terminal domains, standard deviations above that expected for a run of 20 randomized pairs of proteins having the same amino acid compositions as the two proteins under consideration.

Amino Acid Sequence↗
PubMed1991

Mode of membrane insertion and sequence of a 32-amino acid peptide stretch of the penicillin-binding protein 4 of Enterococcus hirae.

Analysis of water-soluble derivatives of the Enterococcus hirae 75-kDa membrane-bound penicillin-binding protein 4 (PBP4) has yielded the amino acid sequence of a 32-amino acid polypeptide stretch. This peptide is similar to peptide segments known to occur in the N-terminal domain of high-Mr PBPs of class B. The E. hirae PBP4 probably belongs to the same class. It is anchored in the membrane at the N-terminus of the polypeptide chain.

Amino Acid Sequence↗
PubMed1991

Bioconversion of a L-carnitin precursor in a one- or two-phase system.

The ability of the yeast Saccharomyces cerevisiae to bioconvert stereo-selectively octyl-4-chloroacetoacetate (OCA) into the corresponding chiral alcohol, precursor of L-carnitin, an important physiological agent, was investigated. In a monophasic system with free cells, more than 90% of OCA (0.018 M) bioconversion have been reached after 6 h (enantiomeric excess for the R form, eeR:97%). Immobilized cells in alginate beads were less efficient in conversion of OCA than free cells. In a two-phase system with free cells, the level of reduction of OCA (0.018 M) reached 85% after 48 h. With a medium containing a higher OCA concentration (0.270 M), 41% of this product were bioconverted after the same period. On the other hand, immobilized cells did not show any significant bioconversion of OCA in two-phase reactors. The limiting factor of these reactors in the regeneration of the cofactors involved in the OCA reduction.

Acetoacetates↗