PubMed Health⌕ Search

Biomedical subjects

A Mattsson

Publications and source records attributed to A Mattsson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Local and systemic immune responses in humans against Helicobacter pylori antigens from homologous and heterologous strains.

The capacity of Helicobacter pylori to induce strain specific immune responses was studied in adult Swedish volunteers. Sera and gastric aspirates from 11 H. pylori-infected subjects were tested for specific antibody levels against, respectively, lipopolysaccharides (LPS) and total membrane preparations (MPs) prepared from the study subjects' own strains, as well as with corresponding antigens from two reference H. pylori strains or heterologous strains collected from other subjects within the study. It was found that sera from five of the 11 subjects had significantly higher IgA antibody titres against LPS from the homologous strain than against LPS from either of the reference strains and in five cases sera reacted with higher IgG titres against the homologous LPS than with LPS preparations from the reference or heterologous patient strains. Analyses of specific titres against MPs revealed that six sera had higher IgA titres and four sera had higher IgG titres against MPs prepared from the subjects' own strains than against MPs from either of the two reference strains. Determination of specific antibodies in gastric aspirates revealed significantly higher IgA titres against LPS from the homologous H. pylori isolate than against LPS from the two reference strains in five cases, and six aspirates reacted in higher IgA titre with the homologous H. pylori MPs. Results from immunoblotting analyses of sera support induction of strain specific immune responses against H. pylori LPS. By means of specific monoclonal antibodies against H. pylori LPS, antigenic heterogeneity between the different LPS preparations tested was confirmed.

Adult↗
PubMed1997

Breast conserving surgery for invasive breast cancer: risk factors for ipsilateral breast tumor recurrences.

To identify risk factors associated with an increased risk for ipsilateral breast tumor recurrence following breast-conserving surgery, a cohort of 759 women with T1-T2 tumors were studied. The majority of the patients (88%) had received postoperative radiation therapy to the breast. Median follow-up time was 10 (range: 6-17) years. There was a 1-1.5% yearly increase in ipsilateral breast tumor recurrences. For women < 50 ys the cumulative recurrence rate at 10 years was 18% and for women > or = 50 ys, 9%. Node positive women had a cumulative breast recurrence rate of 25% versus 10% for node negative women. Ten years postoperatively, irradiated patients had a cumulative recurrence rate of 11% versus 26% when no irradiation was given. The beneficial effect of radiotherapy was substantial during the first four postoperative years. The relative risk for an ipsilateral breast tumor recurrence during this period was 4.5 times higher than for non-irradiated patients. However, the protective effect of radiotherapy decreased with time. After ten years the relative risk of ipsilateral breast tumor recurrence was the same among irradiated and non-irradiated patients although the number of events during this period was low. Univariate analysis showed that seven factors were significantly associated with an increased risk of ipsilateral breast tumor recurrence, namely age < 50 ys, increasing tumor size, uncertain microscopic margins, axillary lymph node metastases, no postoperative tamoxifen treatment, premenopausal status, and no postoperative radiotherapy. Three factors remained independently significant after multivariate analysis: age < 50 ys, no postoperative radiation therapy, and positive lymph nodes. In conclusion, radiotherapy reduced the breast recurrence rate, but the effect decreased with time. Node-negative women > or = 50 were a low risk-group for ipsilateral breast tumor recurrence, with a cumulative risk at 10 years of 9% without radiation therapy and 5% with breast irradiation.

Adult↗
PubMed1997

Relationship between interdigestive motility and secretion of immunoglobulin A in human proximal small intestine.

In 17 healthy volunteers, we studied the dynamics of secretory immunoglobulin A (SIgA) release in the proximal small intestine (distal duodenum and proximal jejunum), using a modified triple-lumen perfusion technique. Secretory data were related to the current phase of the migrating motor complex (MMC), as recorded by manometry. In both segments, luminal SIgA output changed cyclically, with peak outputs occurring at the end of the MMC cycle (late phase II). These MMC-related changes were due to two factors: cyclic inflow of SIgA from more proximal sites, and a cyclic release of SIgA from the test segment that correlated in time with an increase in epithelial fluid secretion. Cyclic intestinal SIgA release may thus be another secretory component of the MMC. The data are compatible with the hypothesis that motility and SIgA release are linked by motility-activated chloride secretion from the intestinal crypts.

Adult↗
PubMed1997

Lack of detectable major histocompatibility complex class II a beta-chain messenger ribonucleic acid in placentas of interferon-gamma- and 5-azacytidine-treated mice.

Trophoblast cells do not normally express major histocompatibility complex (MHC) class II antigens during placental development in either mice or rats. We have previously observed that in vivo treatment of pregnant mice with interferon-gamma (IFN gamma) induces immunohistochemically detectable class II cell surface expression in many maternal cell types, but not on placental cells or other cells of extra-embryonic origin. Both IFN gamma- and 5-azacytidine-induced placental class II expression have been reported in mice by other scientists, however, which made it important to further clarify this issue. The present study was performed to analyze whether treatment of pregnant mice with recombinant IFN gamma or the drug 5-azacytidine in vivo can induce detectable MHC class II Ab mRNA expression. A strain of transgenic mice carrying a cytomegalovirus-regulated MHC class II Abq transgene, which was strongly expressed in the placenta, was used as a positive control in all in situ hybridizations and ribonuclease protection analyses. All mice were analyzed on gestation Days 12.5 and 17.5. Treatment of pregnant mice with IFN gamma did not induce detectable class II expression in the placental cells, whereas the maternal decidua showed expression both at the mRNA and protein level. Similarly, treatment with 5-azacytidine did not induce class II expression in the placenta, while a slight increase in mRNA expression was detected in the maternal decidual and uterine tissues. These results strengthen the opinion that MHC class II mRNA cannot normally be induced in murine placental cells after IFN gamma or 5-azacytidine treatments.

Animals↗
PubMed1997

Incidence of primary malignancies other than breast cancer among women treated with radiation therapy for benign breast disease.

This report presents data on the long-term risks of developing malignancies other than breast cancer after exposure to scattered doses of ionizing radiation. The estimates were based on a cohort of 3,090 women who were diagnosed clinically with benign breast disease between 1925 and 1961. A total of 1,216 women were treated with radiation therapy. The breasts received a mean absorbed dose of 5.84 Gy. Mean absorbed doses owing to scatter to 14 other organs were also determined. The lung received the highest mean scattered dose (0.75 Gy; range 0.004-8.98 Gy) and rectum the lowest (0.008 Gy; range 0-0.06 Gy). Median age at first exposure was 40 years. The follow-up lasted up to 61 years after treatment (mean follow-up 27 years). End-point data were obtained from population-based registers. With internal reference the relative risk for non-breast solid tumors was 1.2 (95% confidence interval 1.0-1.5). However, this excess was not apparent when comparison with the general population was made (standardized incidence ratio = 0.95; 95% confidence interval 0.84-1.07). Among individual sites no significantly increased risks were observed. For stomach cancer there was a linear increase with dose (ERR/Gy = 1.3; two-sided P = 0.05). No increased risk was observed for leukemias. In two earlier reports, breast cancer incidence has been shown to be significantly increased in this cohort of irradiated women. Our results suggest that the scattered doses from the breast irradiation may have increased the risk of cancers of other sites, but the small number of cases in different locations precludes strong interpretations.

Breast Diseases↗
PubMed1996

Maternal antibodies protect immunoglobulin deficient neonatal mice from mouse hepatitis virus (MHV)-associated wasting syndrome.

PROBLEM: Neonatal mice nursed by dams lacking immunoglobulins (Igs) may often suffer from lethal runting if raised under conventional conditions. The present study was performed in order to clarify a) the cause of the wasting syndrome and b) the protective role of antigen-specific milk antibodies. METHOD: Ig-deficient mouse embryos in a conventional environment were embryo-transferred to specified pathogen free (SPF) dams. Neonatal growth, mortality, and health status of mice from both environments was recorded. Suspected presence of mouse hepatitis virus (MHV) was tested by RT-PCR. Protective effects on neonatal mortality of milk containing different titers of anti-MHV antibodies were investigated in cross-fostering experiments. RESULTS: The SPF colony of Ig-deficient mice exhibited no breeding problems, whereas Ig-deficient neonates in the conventional environment suffered from lethal wasting syndrome. Serological screening of the mice kept in the two environments revealed that mice in the conventional room had high titers of antibodies against mouse hepatitis virus. Presence of MHV in runting neonates was confirmed by pathological examinations and RT-nested-PCR using MHV genome specific primers. Milk containing high titers of anti-MHV antibodies, when provided for 8 days or more, completely prevented Ig-deficient neonates from developing wasting syndrome in the conventional environment. CONCLUSION: These findings show that the neonatal wasting syndrome is associated with the presence of MHV and that neonates are efficiently protected by MHV-specific antibodies in the milk.

Animals↗
PubMed1996

Thyroid cancer after diagnostic administration of iodine-131.

To provide quantitative data on the risk of thyroid cancer after exposure to 131I, 34,104 patients administered 131I for diagnostic purposes were followed for up to 40 years. The mean thyroid dose was estimated as 1.1 Gy, and 67 thyroid cancers occurred in contrast to 49.7 expected (standardized incidence ratio = 1.35; 95% confidence interval 1.05-1.71). Excess cancers were apparent only among patients referred because of a suspected thyroid tumor, and no increased risk was seen among those referred for other reasons. Further, risk was not related to radiation dose to the thyroid gland, time since exposure or age at exposure. The slight excess of thyroid cancer thus appeared to be due to the underlying thyroid condition and not radiation exposure. Among those under age 20 years when 131I was administered, a small excess risk (3 cancers compared to 1.8 expected) was about 2-10 times lower than that predicted from data for the A-bomb survivors. These data suggest that protraction of dose may result in a lower risk than an acute X-ray exposure of the same total dose.

Adolescent↗
PubMed1996

Breast cancer after radiotherapy for skin hemangioma in infancy.

Between 1920 and 1959, 9675 women were irradiated in infancy for skin hemangioma at Radiumhemmet, Stockholm. They were exposed to low to moderate doses of ionizing radiation. The mean age at first exposure was 6 months and the mean absorbed dose to the breast anlage was 0.39 Gy (range <0.01-35.8 Gy). The breast cancer incidence was analyzed by record linkage with the Swedish Cancer Register for the period 1958-1986. Seventy-five breast cancers were found [standardized incidence ratio = 1.24; 95% confidence interval (CI) 0.98-1.54] after a mean absorbed dose of 1.5 Gy in the breasts with cancer. The analyses showed a significant dose-response relationship with a linear model estimate for the excess relative risk (ERR) of 0.38 at 1 Gy 95% CI 0.09-0.85). This relationship was not modified significantly by age at exposure or by dose to the ovaries. The ERR increased significantly with time after exposure and for > or = 50 years after exposure the ERR at 1 Gy was 2.25 (95% CI 0.59-5.62). The fitted excess absolute risk (EAR) was 22.9 per 10(4) breast-year gray. The breast absorbed dose and time after exposure were important risk determinants for breast cancer excess risk. Forty to 50 years of follow-up was necessary for the excess risk to be expressed. The study confirms previous findings that the breast anlage of female infants is sensitive to ionizing radiation.

Breast Neoplasms↗
PubMed1996

Thyroid nodularity after diagnostic administration of iodine-131.

In contrast to external X and gamma radiation, radiation from internally deposited 131I has not been clearly shown to cause thyroid tumors or nodules. Given the wide use of 131I in medicine and concern about health risks associated with the release of radioiodines from nuclear reactors, more information is needed. The purpose of this study was to evaluate the risk of thyroid nodularity among women previously exposed to radioiodine (131I) for diagnostic reasons. A clinical examination survey, including thyroid palpation, was conducted for a sample of women drawn from a cohort of patients exposed to 131I and a comparison group of women attending a mammography screening clinic. The study was conducted during 1991-1993 at Radiumhemmet, Karolinska Hospital, Stockholm, Sweden. A total of 1,005 women referred for a thyroid scintigraph or tracer test during the period 1952-1977 were included in the study. For comparison, 248 nonexposed women attending a mammography screening clinic were also enrolled. The primary outcome measure was the presence or absence of palpable thyroid nodules at the time of the clinical examination. Odds ratios were used as estimates of relative risk (RR). The mean dose to the thyroid from 131I was 0.54 Gy, and the average age at 131I administration was 26 years. The prevalence of thyroid nodularity was 10.6% among women who had been exposed to 131I and 11.7% among the nonexposed women [RR = 0.9; 95% confidence interval (CI) 0.6-1.4]. When analysis was restricted to women exposed to 131I, prevalence was associated positively with thyroid dose (excess RR = 0.9 per Gy; 95% CI 0.2-1.9). However, the excess RR was similar for women exposed before age 20 years and those exposed after age 20, which is contrary to findings for populations exposed to external radiation. While results demonstrated a positive association between diagnostic administration of 131I and the subsequent occurrence of thyroid nodules, it is unclear whether the association is causal, as the possibility of confounding by indication for 131I administration cannot be ruled out. No tumors that were subsequently diagnosed as cancer were found during the thyroid examinations, which supports the view that exposure to 131I administered for diagnostic reasons during adulthood rarely causes thyroid cancer.

Adolescent↗
PubMed1995

Non-Hodgkin's lymphoma and skin malignancies--shared etiology?

The Stockholm-Gotland Cancer Register was used to evaluate the clinical observation that patients with non-Hodgkin's lymphoma (NHL) had an increased risk of malignant melanoma or squamous-cell carcinoma of the skin (SCCS) and vice versa. During 1958-1992, NHL was diagnosed in a total of 6,176 patients. Of these patients, 504 developed a second primary cancer of any type except NHL, compared to 301.9 expected, giving a standardized incidence ratio (SIR) of 1.7 [95% confidence interval (CI) 1.5-1.8]. The risk of SCCS and malignant melanoma in patients with NHL was 4.8 (95% CI 3.6-6.2; n = 54) and 1.7 (95% CI 0.8-3.1; n = 10), respectively. The hazard risk for a second malignancy was relatively constant over time, whereas the skin malignancies revealed the highest risks 3-10 years after initial diagnosis. Similarly, the risk of a secondary NHL was studied in patients with malignant melanoma and SCCS during the same period and found to be 1.3 (95% CI 0.8-2.1; n = 17) and 1.8 (95% CI 1.2-2.5; n = 34), respectively. The highest risk for NHL following malignant melanoma was seen 3-10 years after first diagnosis, while the highest risk following SCCS was observed 0-2 years after initial diagnosis. One of several possible explanations or the development of NHL and a skin malignancy in the same patient is an immunological defect caused by sun exposure.

Aged↗
PubMed1995

Adolescent depression: effects of mutuality in the mother-adolescent dyad and locus of control.

A group of 213 adolescents and their mothers participated in a study of the combined relationship between gender, locus of control, and perceived mutuality in the mother/adolescent dyad and self-rated adolescent depression. High mutuality and internal locus of control were significantly related to low levels of depression for both female and male adolescents. The study findings are considered in the context of current theoretical work on female relational psychology.

Adolescent↗
PubMed1995

Dose- and time-response for breast cancer risk after radiation therapy for benign breast disease.

Exposure of the breast to ionising radiation increases the risk of breast cancer, especially among young women. However, some issues remain controversial, for instance the shape of the dose-response curve and the expression of time-related excess. The main purpose of this report was to examine the dose-response curves for radiation-induced breast cancer formulated according to radiobiological target theories. Another purpose was to analyse the time-related excess of breast cancer risk after exposure when dose and age at first exposure were held constant. Breast cancer incidence was analysed in a cohort of 3090 women diagnosed with benign breast disease during 1925-61 (median age 37 years). Of these, 1216 were treated with radiation therapy. The dose range was 0-50 Gy (mean 5.8 Gy). The incidence rate as function of dose was analysed using a linear-quadratic Poisson regression model. Cell-killing effects and other modifying effects were incorporated through additional log-linear terms. Additive and multiplicative models were compared in estimating the time-related excess. The analysis, which was based on 278 breast cancer cases, showed a linear dose-response relationship at low to medium dose levels with a cell-killing effect of 5% Gy-1 (95% confidence interval 2-9%). For a given absorbed dose and age at first exposure the time-related excess was proportional to the background rates with a suggestion that the excess remains throughout life.

Adolescent↗
PubMed1995

Adequate locoregional treatment for early breast cancer may prevent secondary dissemination.

PURPOSE: To analyze different events that determine event-free survival (EFS) in a randomized trial on adjuvant radiotherapy in early breast cancer patients with more than 15 years of follow-up evaluation. PATIENTS AND METHODS: The trial included 960 patients with a unilateral, operable breast cancer. Surgery consisted of a modified radical mastectomy. The trial compared three arms, as follows: preoperative radiotherapy, postoperative radiotherapy, and no adjuvant treatment. Events were analyzed by a competing-risk approach. A proportional hazards multiple regression model was used to analyze the effects of radiotherapy on the risk of distant metastasis. Similar analyses were performed separately for node-negative [N(-)] and node-positive [N(+)] patients in the two groups that did not include preoperative radiotherapy. RESULTS: Radiotherapy produced a fivefold decrease of the risk of local recurrence (P < .0001). In N(+) patients, postoperative radiotherapy decreased the risk of distant dissemination (relative risk, 0.63). When local recurrence was introduced in the model as a time-dependent covariate, this factor was predictive of distant dissemination (P < .0001) and nullified the effect of postoperative radiotherapy. This finding suggests that the decrease of distant metastases was related to the prevention of local recurrence. A similar effect was found in models that used overall survival as an end point. CONCLUSION: This study shows that postmastectomy radiotherapy in N(+) breast cancer patients may decrease the distant metastasis rate by preventing local recurrences and thus avoiding secondary dissemination.

Breast Neoplasms↗
PubMed1995

Gastric output of IgA in man: relation to migrating motility complexes and sham feeding.

BACKGROUND/AIMS: The immunologic reactivity of the gastric mucosa is poorly understood. The origin and dynamics of immunoglobulin A (IgA) occurring in the gastric lumen were investigated in healthy, Helicobacter pylori-negative volunteers. METHODS: Gastroduodenal manometric motility recordings were combined with gastric luminal perfusion, enabling calculation of gastric acid output and analysis of the total IgA output. RESULTS: Acid output and total IgA correlated with the migrating motility complexes (MMC). The gastric IgA release showed maximal values in association with gastric motility phase III (maximal motor activity) and lowest values during phases I and II (none or irregular motor activity). The IgA output correlated with neither swallowed saliva (as indicated by amylase in the gastric perfusate) nor duodenogastric reflux (as indicated by gastric occurrence of bilirubin and/or duodenally infused PEG4000). Stimulation of gastric acid secretion by sham feeding during phase II-like motor activity (n = 6) induced a rapid and transient doubling of IgA output. There was no significant correlation between gastric acid secretion and gastric IgA release. CONCLUSION: Substantial amounts of IgA are released into the human stomach, most likely originating from the gastric mucosa. The up-regulation of IgA release in association with the activity front of the MMC and anticipatory to food intake suggests a neuroendocrine control of gastric mucosal immune responses.

Adult↗