Biomedical subjects

M Gottschalk

Publications and source records attributed to M Gottschalk.

At least 19 recordsLinked to original sources

PubMed2006

Bone mass and the risk of breast cancer: the influence of cumulative exposure to oestrogen and reproductive correlates. Results of the Marburg breast cancer and osteoporosis trial (MABOT).

BACKGROUND: Recent studies suggest an inverse relation between breast cancer and osteoporosis. Oestrogen is important in the pathophysiology of both breast and bone, and although cumulative exposure to oestrogen may explain the link between breast cancer and bone mass, this has never been proved. The Marburg breast cancer and osteoporosis trial (MABOT) aimed to elucidate the relation between breast cancer and bone mass ascertained by ultrasonometry measurement and to investigate whether endogenous and exogenous exposure to oestrogen and reproductive correlates has a role in this association. METHODS: We performed a case-control study including 2492 women (mean age+/-S.D., 54.4+/-10.3 years) in whom diseases and drug treatments known to affect bone metabolism, except for HT, had been excluded. All women underwent ultrasonometry measurement at the heel; 242 of the women had an incident breast cancer without a prior, specific pharmacological breast cancer treatment. The ultrasonometry variables - speed of sound (SOS), broadband ultrasound attenuation (BUA) and the stiffness index (SI) - were calculated and compared in women with and without breast cancer. Because of significant intergroup differences in factors such as age, body mass index and exposure to oestrogen, a multiple linear regression analysis as well as a second analysis of ultrasonometry variables was undertaken using a randomly selected sample of 242 healthy women post-matched with the breast cancer group for possible confounding variables. Odds ratios were used to compare the relation between breast cancer risk and ultrasonometry heel measurements. RESULTS: Women with breast cancer were significantly older, weighed more, had a higher body mass index, were more likely to be parous and to have breast fed, were older at the menopause and had been exposed to oestrogen for longer than control women. In addition, the ultrasonometry variables speed of sound and the stiffness index T- and Z-score were significantly higher in women with breast cancer even after a matched pair analysis was performed (p<0.001). Additionally, results of a multiple linear regression showed that women with breast cancer had a significantly higher SOS (p<0.001), body weight (p<0.05) and duration of breast feeding (p<0.05) while osteoporotic fracture were reduced (p<0.001). When women with breast cancer and their matched controls were finally grouped according to SOS and T-score quartiles, the odds ratios (95% confidence intervals) for breast cancer risk in the second, third and fourth quartiles compared with the lowest quartile were 2.5 (1.4-4.3), 3.1 (1.8-5.3) and 4.7 (2.7-8.2) as well as 1.9 (1.1-3.2), 2.3 (1.3-3.9) and 2.9 (1.7-5.0), respectively. CONCLUSIONS: The ultrasonometry variables speed of sound, stiffness index, T- and Z-score are higher in women with an incident breast cancer than in healthy controls, even after post-matching for possible confounding variables. This association was confirmed in a multiple linear regression model. Women with SOS and T-score values in the higher quartiles have a greater risk of breast cancer than women in the lowest quartile. We found no association between the higher ultrasonometry variables and cancer specific characteristics or reproductive correlates such as age at menarche and menopause or cumulative oestrogen exposure. Although the biological mechanisms linking bone mass and the risk of breast cancer are not fully understood, factors other than reproductive correlates, endogenous and exogenous exposure to oestrogen must play a part.

Adult↗

PubMed2006

Field evaluation of four novel enzyme immunoassays for Chagas' disease in Venezuela blood banks: comparison of assays using fixed-epimastigotes, fixed-trypomastigotes or trypomastigote excreted-secreted antigens from two Trypanosoma cruzi strains.

Many serological tests have been developed for the diagnosis of Chagas' disease, but few have been subjected to a rigorous field evaluation. We have recently described several novel enzyme immunoassays (EIAs) based on fixed-whole organisms or trypomastigote excretory-secretory antigens (TESA) from different Trypanosoma cruzi strains (Tulahuen or Brazil). This study evaluated the most promising of these novel assays (e.g. fixed-epimastigotes, fixed-trypomastigotes, TESA Brazil and TESA Tulahuen antigens) in a field study of Venezuelan blood bank specimens. The assays were tested in an operator-blinded fashion using 2038 blood bank samples obtained from low and high T.cruzi prevalence regions of Venezuela (n= 1050 and n= 988 from Bolivar and Portuguesa states, respectively). Based on National Laboratory for Chagas Immunodiagnosis (NLCI) 'gold standard' results, all novel EIAs were superior to the commercial kit currently used in Venezuela, achieving 100% sensitivity and >99% specificity at optimal cut-off values. The novel assays identified seven false-negative samples compared with the routine screening performed by the Venezuelan blood bank although two samples were also misclassified as positive. Minor differences in the performance of the four novel assays were observed at lower arbitrary cut-off values. This study confirms the potential utility of both the fixed-organism and the TESA-based assays in the diagnosis of T.cruzi infection.

Adolescent↗

PubMed2005

Normal CFTR Activity and Reversed Skin Potentials in Pseudohypoaldosteronism.

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) Cl(-) channel function is required for activating amiloride-sensitive epithelial Na(+) channels (ENaC) in salt-absorbing human sweat duct. It is unclear whether ENaC channel function is also required for CFTR activation. The dysfunctional ENaC mutations in type-1 pseudohypoaldosteronism (PHA-1) provided a good opportunity to study this phenomenon of ion channel interaction between CFTR and ENaC. The PHA-1 ducts completely lacked spontaneous ENaC conductance (gENaC). In contrast, the normal ducts showed large spontaneous gENaC (46 +/- 10 ms, mean +/- SE: ). After permeabilization of the basolateral membrane with alpha-toxin, cAMP + ATP activation of CFTR Cl(-) conductance (gCFTR) or alkalinization of cytosolic pH (6.8 to 8.5) stimulated gENaC of normal but not PHA-1 ducts. In contrast, both spontaneous gCFTR in intact ducts and (cAMP + ATP)-activated gCFTR of permeabilized ducts appeared to be similar in normal and PHA-1 subjects. Lack of gENaC completely blocked salt absorption and caused dramatic reversal of skin potentials associated with pilocarpine-induced sweat secretion from significantly negative in normal subjects (-13 +/- 7.0 mV) to significantly positive (+22 +/- 11.0 mV) in PHA-1 patients. We conclude that virtual lack of ENaC in PHA-1 ducts had little effect on CFTR activity and that the positive skin potentials could potentially serve as a diagnostic tool to identify type-1 pseudohypoaldosteronism.

Cystic Fibrosis Transmembrane Conductance Regulato↗

PubMed2005

Assessment of the efficacy of tilmicosin phosphate to eliminate Actinobacillus pleuropneumoniae from carrier pigs.

The aim of this study was to evaluate the efficacy of in-feed medication with tilmicosin phosphate in order to eliminate or reduce the carriage of Actinobacillus pleuropneumoniae in the tonsils of carrier pigs. Two groups of 6 carrier animals received either a non-medicated feed (control group) or feed medicated with 400 ppm of tilmicosin phosphate (treated group) for 30 d. Three sentinel pigs were then introduced in each group and left for 29 d. The presence of A. pleuropneumoniae in tonsils was monitored using several techniques, including polymerase chain reaction (PCR). At the end of the treatment all of the control animals, but only 1 treated pig, were positive by PCR from tonsillar surface material. However, at necropsy, all control and most treated animals, as well as 1 sentinel animal, in both groups were positive by PCR from whole tonsils. In conclusion, under the experimental conditions, in-feed treatment with 400 ppm of tilmicosin phosphate significantly reduced the presence of A. pleuropneumoniae on the surface of tonsils but was unable to completely eliminate the organism from deeper tonsillar tissues and to prevent bacterial shedding by carrier animals.

Actinobacillus Infections↗

PubMed2004

Production and characterization of murine monoclonal antibodies against Haemophilus parasuis and study of their protective role in mice.

Monoclonal antibodies (MAbs) against Haemophilus parasuis were obtained by the fusion of SP2/0-Ag14 murine myeloma cells and spleen cells from BALB/c mice immunized with a whole-bacterial-cell suspension (WC) of H. parasuis strain SW124 (serotype 4). Two MAbs showing strong reactivity in ELISA were further characterized using SDS-PAGE and Western-blot assays. Different treatments of the WC indicated that MAbs 4D5 and 4G9 identified epitopes of proteinic and polysaccharidic nature, respectively. Electron microscopic examination revealed that, unlike the proteinic epitopes, the lipopolysaccharidic epitopes were exposed on the surface of the cell. Using coagglutination, Western-blot and dot-blot assays it was found that both MAbs recognized common epitopes of all the reference strains and field isolates of H. parasuis. None of the other bacteria tested reacted with the MAbs. These results indicated that both the proteinic and polysaccharidic antigens carried species-specific epitopes. It is suggested that these MAbs may potentially be useful for identification of H. parasuis isolates as well as for developing serological diagnostic tools. MAbs 4D5 and 4G9 were unable to kill H. parasuis in vitro in the presence of complement. However, an enhanced bacterial clearance from blood was observed in mice inoculated with either of the MAbs. Highly significant protection was observed in mice using MAb 4G9. This is believed to be the first report of MAbs capable of identifying common species-specific antigens of H. parasuis and of their implication in protection against challenge infection in mice.

Amino Acid Sequence↗

PubMed2004

Development of a new serological test for serotyping Haemophilus parasuis isolates and determination of their prevalence in North America.

Haemophilus parasuis causes polyserositis in swine. Fifteen serovars have been characterized by immunodiffusion test, but many field strains are not typeable. Isolates (n = 300) of H. parasuis from animals in North America were serotyped by a new indirect hemagglutination test. The test was rapid and effective for serotyping of H. parasuis, and serovars 4, 5, 13, and 7 were the most prevalent serotypes.

Animals↗

PubMed2004

Multiplex PCR assay for detection of Streptococcus suis species and serotypes 2 and 1/2 in tonsils of live and dead pigs.

A PCR assay was developed for the detection of Streptococcus suis serotypes 2 and 1/2. This multiplex PCR is based on the amplification of the gene coding for 16S rRNA of S. suis and on the amplification of the cps2J gene coding for the capsule of S. suis serotypes 2 and 1/2. An internal control was constructed and added in this test to monitor the efficiency of amplification in each reaction. To evaluate the specificity of the test, 31 strains of other bacterial species related to S. suis or isolated from pigs and 42 strains of S. suis serotypes 1 and 3 to 34 were analyzed. The detection threshold of the test was 28 S. suis CFU/ml. The specificity and the sensitivity of the multiplex PCR test and the presence of an internal control allowed the analysis of biological samples without a culture step. The PCR assay was then applied to the detection of 14 S. suis serotype 1/2 strains, 88 S. suis serotype 2 strains isolated from pigs, and 25 S. suis serotype 2 strains isolated from humans. This test was also applied to analyze tonsil samples of pigs experimentally infected and carrier pigs without any symptoms.

Animals↗

PubMed2004

Cytokine mRNA expression in patients with multiple sclerosis and fatigue.

BACKGROUND: Fatigue is one of the most common disabling symptoms in patients with multiple sclerosis (MS), but the putative role of proinflammatory cytokines remains to be elucidated. METHODS: Thirty-seven patients (27 women, 10 men) with relapsing remitting (n = 29) and secondary progressive (n = 8) MS, aged 41.0 +/- 10.2 years, were studied. Fatigue was assessed by Krupp's Fatigue Severity Scale (FSS). Cytokine mRNA expression for interferon (IFN)-gamma tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 were measured by real time RT PCR. Autonomic function was evaluated by standard tests for parasympathetic and sympathetic function, as well as by serum levels of norepinephrine and epinephrine. RESULTS: Median levels of TNF-alpha mRNA expression were significantly higher in MS patients with (FSS > or = 4.0 and > or = 5.0, n = 26 and n = 14, respectively) than in those without fatigue (FSS < 4.0, n = 11). No differences were seen for IFN-gamma and IL-10 mRNA expression. Cytokine levels were not correlated to autonomic tests or to serum catecholamine levels. CONCLUSIONS: These results suggest that TNF-alpha, as a principal proinflammatory mediator, is associated with MS-related fatigue. This is in support of a pathogenic role of the MS-related inflammatory process in the development of fatigue.

Adult↗

PubMed2004

Efficacy of tilmicosin in the control of experimentally induced Actinobacillus pleuropneumoniae infection in swine.

The efficacy of tilmicosin administered in the feed to control Actinobacillus pleuropneumoniae infections in pigs was evaluated through a multisite, multitrial study. For each of 6 trials, 48 pigs (stratified by weight and sex) were randomly assigned to 6 to 8 pens. Medicated feed containing tilmicosin (200 g/t) and unmedicated feed were randomly assigned at the pen level and were provided ad libitum from day -7 to trial termination (day 14). Seeder pigs (inoculated intranasally with A. pleuropneumoniae serotype 1 and showing signs of clinical disease) were introduced to each pen on day 0. Rates of death, gross lesions, and culture of A. pleuropneumoniae at necropsy, clinical scores, average daily gain in weight, and average body temperature were compared between the medicated and unmedicated pigs. Compared with the unmedicated pigs, significantly fewer (P < 0.05) pigs given tilmicosin had lesions typical of A. pleuropneumoniae or had A. pleuropneumoniae isolated from their tissues at necropsy. Together with a significant reduction (P < 0.05) in the average percentage of pneumonic lung involvement (both visually and by weight), there were reductions in the numbers of pigs with moderate and severe pneumonic lung lesions and with A. pleuropneumoniae associated mortality. With tilmicosin treatment, the average daily weight gain, daily temperature, abdominal appearance, attitude, and respiration were also significantly better (P < 0.05). The results of this study demonstrate the in vivo effectiveness of tilmicosin (200 g/t) in controlling pleuropneumonia among swine experimentally infected with A. pleuropneumoniae.

Actinobacillus Infections↗

PubMed2003

Epidemiology of Streptococcus suis serotype 5 infection in a pig herd with and without clinical disease.

The aim of this study was to describe the transmission and the kinetics of the infection caused by Streptococcus suis serotype 5 in a multisite farrow-to-finish pig herd. Most sows carried S. suis serotype 5 in their vaginal tract, but not in their nasal cavities, as demonstrated by immunomagnetic separation (IMS) technique. Their offspring became infected during farrowing, confirming vertical transmission. During the first 4 weeks of life, a low number of piglets were carriers of S. suis serotype 5 in their nasal cavities. However, when clinical signs appeared, the carrier rate significantly increased, suggesting that isolation from nasal cavities is a better indication of active transmission than of a carrier state. Clinical cases were present in animals between 4 and 8 weeks of age, when maternal antibodies were at their lowest level. Up to six different genotypes of the same serotype could be identified by random amplified polymorphic DNA; however, a single clone was responsible for all clinical cases studied. This clone could only be isolated from a single sow, indicating that its prevalence in breeding animals was low. Interestingly, 1 year later, clinical disease associated with S. suis serotype 5 spontaneously disappeared. At that time, the genotype responsible for the clinical signs was not detected in the herd and the levels of antibodies in sows and maternal antibodies in piglets were not higher than those of the previous year.

Animals↗

PubMed2003

Non-pathogenic Actinobacillus isolates antigenically and biochemically similar to Actinobacillus pleuropneumoniae: a novel species?

Two unusual Actinobacillus isolates were recovered from pigs with no clinical signs, no lesions and no history of swine pleuropneumonia. Two representative strains (9953L55 and 0347) analyzed in this study were initially biochemically and antigenically identified as A. pleuropneumoniae serotypes 1 and 9, respectively, by traditional identification methods. Both strains presented, however, negative results with three A. pleuropneumoniae-specific PCR tests and revealed in particular the absence of the apxIV toxin genes. However, both strains produced and secreted ApxII toxin although they only harbored the toxin genes apxIICA, which is an uncommon feature for any of the known A. pleuropneumoniae serotypes. Upon experimental inoculation of pigs, these strains proved to be totally non-pathogenic. Animals infected with one of the strains produced antibodies that cross-react with A. pleuropneumoniae serotypes 1-9-11-specific LC-LPS ELISA. Phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that these strains form a separate phylogenetic group that is distinct from other Actinobacillus species and is particularly different from A. pleuropneumoniae.

Actinobacillus↗

PubMed2003

Up-regulation of ICAM-1, CD11a/CD18 and CD11c/CD18 on human THP-1 monocytes stimulated by Streptococcus suis serotype 2.

Streptococcus suis serotype 2 is known to be a major pathogen of swine, causing mainly meningitis. It is also a zoonotic agent leading predominantly to meningitis in humans working in close contact with pigs. In this study, we investigated the ability of S. suis to up-regulate the expression of adhesion molecules involved in inflammation, using an enzyme-linked immunosorbent assay. S. suis serotype 2 stimulated the up-regulation of the expression of intercellular adhesion molecule-1 (ICAM-1, CD54), CD11a/CD18 and CD11c/CD18 on human THP-1 monocytes, but did not change that of ICAM-1, vascular cell adhesion molecule-1 (VCAM-1, CD106) and E-selectin (CD62E) on human endothelial cells. The up-regulation of adhesion molecules was time- and bacterial concentration-dependent, and cell wall components were largely responsible for such stimulation. To a lesser extent, purified haemolysin of S. suis also stimulated adhesion molecule expression. Stimulation of monocytes with strains of different origin showed that there was no clear tendency for human strains to induce a higher expression of adhesion molecules than strains from diseased pigs. Finally, monocytes stimulated with S. suis also showed an increase in adherence to endothelial cells. Hence, S. suis is capable of up-regulating important adhesion molecules involved in inflammation, which may result in an increased leucocyte recruitment into sites of infection, thus providing a possible mechanism for some of the inflammatory features of meningitis caused by this pathogen.

Antigens, CD↗

PubMed2003

Identification of an inducible bacteriophage in a virulent strain of Streptococcus suis serotype 2.

Streptococcus suis infection is considered to be a major problem in the swine industry worldwide. Most virulent Canadian isolates of S. suis serotype 2 do not produce the known virulence markers for this pathogen. PCR-based subtraction hybridization was adapted to isolate unique DNA sequences which were specific to virulent strains of S. suis isolated in Canada. Analysis of some subtracted DNA clones revealed significant homology with bacteriophages of gram-positive bacteria. An inducible phage (named Ss1) was observed in S. suis following the incubation of the virulent strain 89-999 with mitomycin C. Phage Ss1 has a long noncontractile tail and a small isometric nucleocapsid and is a member of the Siphoviridae family. Ss1 phage DNA appears to be present in most Canadian S. suis strains tested in this study, which were isolated from diseased pigs or had proven virulence in mouse or pig models. To our knowledge, this is the first report of the isolation of a phage in S. suis.

Animals↗

PubMed2003

Clonal distribution of an atypical MRP+, EF*, and suilysin+ phenotype of virulent Streptococcus suis serotype 2 strains in Brazil.

Streptococcus suis is considered one of the most important bacterial swine pathogens worldwide. The distribution of the 35 described serotypes in diseased animals may vary in different regions. Data regarding S. suis isolation from pigs in South America is not available. In the present study, 51 isolates of S. suis recovered in pure culture or as the predominant species from diseased animals in Brazil, were analyzed. These isolates were classified as serotypes 2 (58.8%), 3 (21.5%), 7 (13.7%), 1 (3.9%), and 14 (2%). Serotype 2 isolates were further studied for their production of virulence-related proteins muramidase-released protein (MRP), extracellular factor (EF), and suilysin. In addition, the genetic diversity was studied by randomly amplified polymorphic DNA. All but 1 of the serotype 2 isolates showed a clonal distribution of an atypical phenotype (MRP+, EF*, suilysin+), different from the known European (MRP+, EF+, suilysin+), and North American (MRPv, EF-, suilysin-), phenotypes.

Animals↗

PubMed2002

CD14-dependent and -independent cytokine and chemokine production by human THP-1 monocytes stimulated by Streptococcus suis capsular type 2.

Streptococcus suis capsular type 2 is an important aetiologic agent of swine meningitis, and it has been highlighted as a cause of occupational disease leading to meningitis and fulminant sepsis in humans. The objective of the present work was to study the ability of S. suis type 2 to induce the release of tumour necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), IL-6, IL-8 and monocyte chemotactic protein one (MCP-1) by human monocytic THP-1 cells. The induction of these five cytokines was dose- and incubation time-dependent, and it was significantly enhanced by pre-treatment of cells with interferon gamma. IL-8 levels were markedly higher compared with those obtained with the other cytokines. However, elevated levels of MCP-1 and IL-6 were also observed. Levels of cytokine induced by heat-killed or live bacteria were similar. Pre-treatment of cells with anti-CD14 monoclonal antibodies suggested that this important host receptor is partially implicated in TNF, IL-1, IL-6 and MCP-1 production, while CD14-independent pathways seem to be responsible for IL-8 production after S. suis stimulation. In addition, blocking studies with anti-TNF and anti-IL-1 antibodies revealed that these cytokines are involved in amplification of the S. suis-induced cytokine cascade. When several different S. suis strains of human or porcine origin were compared, a very heterogeneous pattern of cytokine production was observed. Human strains did not exhibit a clear tendency to induce higher cytokine release by human THP-1 monocytes. The synergistic effect of the up-regulation of cytokines during S. suis meningitis may mediate many of the inflammatory reactions, including the sequestration of leucocytes at the site of infection.

Animals↗

PubMed2002

Fatigue in multiple sclerosis: a comparison of different rating scales and correlation to clinical parameters.

OBJECTIVES: Fatigue is one of the most common, yet poorly defined, disabling symptoms in patients with multiple sclerosis (MS). To delineate more clearly the frequency and type of fatigue, we first compared four widely used fatigue scales in consecutive MS patients. Secondly, to further clarify the nature of fatigue, we investigated its relation to physical disability, course of the disease, immunotherapy, and depression. PATIENTS AND METHODS: Between February and September 2000, 151 consecutive MS patients entering our outpatient clinic (94 relapsing-remitting, 50 secondary progressive, and 7 primary progressive patients; mean age 29.0 +/- 7.3 years, mean disease duration 9.9 +/- 6.7 years, median EDSS 3.5) filled in a standardized questionnaire induding four fatigue scales--Fatigue Severity Scale (FSS), MS-specific FSS (MFSS), Modified Fatigue Impact Scale (MFIS), and Visual Analogue Scale (VAS). Patients were included in the 'MS-related fatigue group' (MS-F) when they stated in the questionnaire that fatigue: 1) is one of their three most disabling symptoms; 2) occurs daily or on most of the days; and 3) limits their activities at home or at work Patients fulfilling none of these criteria were classified as 'MS-related nonfatigue group' (MS-NF). Depression was measured by Beck's Depression Inventory (BDI). RESULTS: Although all scales showed significant differences between MS-F and MS-NF, correlation between these scales was, at best moderate (correlation coeffcients ranging from 0.06 to 0.56). The most discriminative scales were FSS and MFIS, showing no overlap of the 10th and 90th percentiles for the MS-F and MS-NF groups, with cut-off values of 4.6 and 38, respectively. Depression (BDI > or = 18) was present in 24 of 148 patients who filled in the BDI (16%). FSS was significantly correlated with physical disability (r=0.33, p<0.0001) and BDI (r=0.41, p<0.0001), but not with age, disease duration, clinical activity, and treatment with interferon-beta. In multivariate analysis, however, only BDI independently predicted fatigue. CONCLUSIONS: The association of fatigue and depression suggests that there might be either common underlying mechanisms or interdependence by a cause-and-effect relationship that requires further investigation. The weak correlation within various fatigue scales is best explained by the fact that fatigue is a multidimensional symptom and, therefore, the available tests measure and weight different aspects of fatigue. Our findings underline the necessity for a more exact definition of fatigue and the development of more valid tools if these are to be used to evaluate treatments.

Adult↗

PubMed2002

Antibody response to an autogenous vaccine and serologic profile for Streptococcus suis capsular type 1/2.

An autogenous vaccine was developed, using sonicated bacteria, with a strain of Streptococcus suis capsular type 1/2. The objectives of this study were to evaluate the antibody response following vaccination and to assess the changes in antibody levels in pigs from a herd showing clinical signs of S. suis capsular type 1/2 infection in 6- to 8-week-old pigs. An enzyme-linked immunosorbent assay using the vaccine antigen was standardized. Results from a preliminary study involving 2 control and 4 vaccinated 4-week-old pigs indicated that all vaccinated pigs produced antibodies against 2 proteins of 34 and 43 kDa, respectively, and, in 3 out of 4 vaccinated pigs, against the 117-kDa muramidase-released protein. For the serologic profile, groups of 30 pigs from the infected herd were blood sampled at 2, 4, 6, 8, and 10 weeks of age. The lowest antibody level was observed between weeks 6 and 8, presumably corresponding to a decrease in maternal immunity. A marked increase was seen at 10 weeks of age, shortly after the onset of clinical signs in the herd. For the vaccination field trial, newly weaned, one-week-old piglets were divided into 2 groups of 200 piglets each (control and vaccinated); blood samples were collected from 36 piglets in each group at 2-week intervals for 12 weeks. A significant increase (P < 0.05) in antibody response was observed 4 weeks following vaccination and the level of antibodies stayed high until the end of the experiment. In the control group, the increase was only observed at 13 weeks of age, probably in response to a natural infection. The response to the vaccine varied considerably among pigs and was attributed, in part, to the levels of maternal antibodies at the time of vaccination. No outbreak of S. suis was observed in the control or vaccinated groups, so the protection conferred by the vaccine could not be evaluated.

Animals↗

PubMed2002

Influence of pregnancy and breast-feeding on quantitative ultrasonometry of bone in postmenopausal women.

OBJECTIVE: Reproductive factors such as parity and breast-feeding may be associated with low bone mass and osteoporotic fractures in later years. In this study, os calcis quantitative ultrasonometry was used to elucidate the relationship between parity, lactation and bone mass in postmenopausal women. DESIGN: This was a comparison study using subsequent matched pairs analysis as well as multiple linear regression analysis. The study was carried out at five centers in Germany. The study included 2,080 postmenopausal women (age (mean +/- SD) 58.8 +/- 8.2 years), who were attending for routine check-up and in whom diseases and drug treatments known to affect bone metabolism had been excluded. METHODS AND OUTCOME MEASURES: Women underwent quantitative ultrasonometry (QUS) measurement at the heel. Values of the ultrasonometry variables -speed of sound, broadband ultrasound attenuation and stiffness index -were calculated and compared for nulliparous and parous women and for women who had and had not breast-fed. Because of some significant intergroup differences, and to determine any effect of the number of live births and the duration of breast-feeding on ultrasonometry results, second analyses were undertaken using equally sized samples, matched for possible confounding variables such as age and body mass index (matched pairs). In these analyses, nulliparous women were compared with parous women, grouped according to number of live births, and women who had never breast-fed were compared with women who had breast-fed, grouped according to duration of breast-feeding. Furthermore, a multiple linear regression analysis was performed to examine the combined effects of reproductive factors on QUS variables. RESULTS: No statistically significant associations were found between ultrasonometry variables and parity or breast-feeding, even after controlling for confounding variables in matched-pairs analysis or in a multiple linear regression analysis.

Adult↗