Search PubMed⌕ Search

Biomedical subjects

M Roos

Publications and source records attributed to M Roos.

At least 91 records · Page 5Linked to original sources
PubMed1988

Sexual differences in the development of accessory olfactory bulbs in the rat.

The aim of this investigation was 1) to compare the development of AOB in male and female rats before birth, early after birth, and at later stages of sexual immaturity and maturity 2) to examine the effects of early and delayed castration after birth on AOB development in the male rat. A significant increase of the surface area of AOB was observed in both sexes from birth until postnatal day 7, but AOB was found to be larger in males than in females. From the end of the first postnatal week AOB stopped growing until day 40 in both males and females. After this time AOB resumed its development until day 60 in males, while no changes occurred in females over the same period. Castration of males at birth or six hours later impaired development of AOB. Castration of males on postnatal days 20 or 30 also impaired AOB development until day 60. The results strongly suggest that the development of AOB in the male rat is dependent on the two well known "perinatal" and "adult" phases of the endocrine activity of the testes.

Age Factors↗
PubMed1988

Decline in CD4+ cell numbers reflects increase in HIV-1 replication.

Changes in CD4+ cell numbers were studied in relation to the presence of HIV-1 antigen (HIV-1-Ag) in serum from homosexual men followed prospectively. During 30 months of follow-up the mean CD4+ cell number (x 10(9) per liter) was stable in 134 at entry HIV-1 antibody (HIV-1-Ab) seropositives, who remained HIV-1-Ag negative (from 0.59 to 0.62) and declined in 38 at entry HIV-1-Ab seropositives who were persistently HIV-1-Ag positive (from 0.43 to 0.34). In sera of 9 of 65 HIV-1-Ab seroconverters HIV-1-Ag was detected only once, 3 months before or concomitantly with antibody seroconversion. Another 11 men became persistently HIV-1-Ag positive with antibody seroconversion or 2-6 weeks thereafter. A decline in CD4+ cell numbers was seen between 6 months before and the moment of HIV-1-Ab seroconversion, independently of duration and level of antigen expression. This indicates initial HIV-1 replication in both HIV-1-Ag negatives and positives. Following antibody seroconversion, HIV-1-Ag negatives had higher CD4+ cell numbers than HIV-1-Ag positives. Similarly to those who were HIV antigenemic from entry of the study, the HIV-1-Ab seroconverters who concomitantly with seroconversion or shortly thereafter became HIV-1 antigenemic showed a steady and significant (p = 0.01) decline in CD4+ cell numbers. In those who remained HIV-1-Ag negative after antibody seroconversion, CD4+ cell numbers were stable during follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Immunological abnormalities in human immunodeficiency virus (HIV)-infected asymptomatic homosexual men. HIV affects the immune system before CD4+ T helper cell depletion occurs.

To investigate the effect of persistent HIV infection on the immune system, we studied leukocyte functions in 14 asymptomatic homosexual men (CDC group II/III) who were at least two years seropositive, but who still had normal numbers of circulating CD4+ T cells. Compared with age-matched heterosexual men and HIV-negative homosexual men, the CD4+ and CD8+ T cells from seropositive men showed decreased proliferation to anti-CD3 monoclonal antibody and decreased CD4+ T-helper activity on PWM-driven differentiation of normal donor B cells. Monocytes of HIV-infected homosexual men showed decreased accessory function on normal T cell proliferation induced by CD3 monoclonal antibody. The most striking defect in leukocyte functional activities was observed in the B cells of HIV-infected men. B cells of 13 out of 14 seropositive men failed to produce Ig in response to PWM in the presence of adequate allogeneic T-helper activity. These findings suggest that HIV induces severe immunological abnormalities in T cells, B cells, and antigen-presenting cells early in infection before CD4+ T cell numbers start to decline. Impaired immunological function in subclinically HIV-infected patients may have clinical implications for vaccination strategies, in particular the use of live vaccines in groups with a high prevalence of HIV seropositivity.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Statistical study of a semiquantitative evaluation of testicular biopsies.

A statistical method was used to evaluate 629 testicular biopsies on which a semiquantitative morphometric analysis was applied. The results confirm with a high level of significance (p less than 0.001) the qualitative knowledge of testicular pathology. Some tight correlations between histological and/or cytological parameters are enlightened.

Biopsy↗
PubMed1988

Effect of selenium supplementation to fertilizers on the selenium status of the population in different parts of Finland.

Concentrations of selenium in the soil are very low in most regions in Finland, which explains the low selenium contents of agricultural plants and the low dietary intake of selenium. The poor selenium status of the population in Finland has been considered a possible risk to public health. In 1984, it was decided to increase the selenium intake by adding selenate to common agricultural fertilizers. In this study, the selenium concentrations of whole blood and plasma, as well as erythrocyte glutathione peroxidase activities, were measured in blood samples from four different localities in Finland, in 1984 and 1986, before and during the agricultural selenium supplementation. A low blood level of selenium in the inhabitants of central Finland was demonstrated in 1984. The selenium level of people from the south-west archipelago was a little higher, and that from the northern part of Finland considerably higher than the level in the rest of the country. By 1986, differences between these localities had almost disappeared, and most levels had increased. Plasma selenium concentrations were lower than those in whole blood samples; the concentrations showed a significant correlation. The glutathione peroxidase activities were at the same level in all four localities in 1984. By 1986, they had all increased to a slightly higher level. A weak correlation was found between erythrocyte glutathione peroxidase activity and blood selenium level.

Adult↗
PubMed1986

Antibodies to the human T-cell lymphoma/leukemia virus type I in Dutch haemophiliacs.

95 Dutch haemophiliacs were tested for antibodies to membrane antigens on cells infected with human T-cell leukemia virus type I (HTLV-I-MA) by indirect immunofluorescence and to purified HTLV-I by enzyme-linked immunosorbent assay. Antibodies to HTLV-I-MA were present in 8 of 95 (8%) haemophiliacs, but only 3 (3%) had antibodies to purified HTLV-I. No clinical disease was related to HTLV-I seropositivity. The importance of iatrogenic HTLV-I transmission to haemophiliacs is discussed.

Antibodies, Viral↗
PubMed1985

Immunologic studies with LFA-1- and Mo1-deficient lymphocytes from a patient with recurrent bacterial infections.

A patient and his parents, deficient for lymphocyte function associated antigen-1 (LFA-1) and Mo1 (OKM1), were studied with respect to leukocyte surface marker expression and functional properties. The patient had a history of severe recurrent bacterial infections. Two siblings had already died of bacterial infections. The patient's granulocytes, monocytes, and lymphocytes expressed low but detectable amounts (less than or equal to 10%) of LFA-1 and Mo1. Intracellularly, LFA-1 and Mo1 (OKM1) were detectable and LFA-1 expression was enhanced on patient T cells stimulated with phytohemagglutinin. Granulocytes and monocytes of both the patient's parents expressed markedly decreased amounts of LFA-1 and Mo1. Lymphocytes of the mother expressed 40 to 60% of the amount of LFA-1 expressed on control lymphocytes, but his father's lymphocytes showed a normal LFA-1 expression. Granulocytes of the patient and of his deceased sister showed normal phagocytosis, but they had a dysfunction in the activation of the oxidative metabolism. Functional activities mediated by patient T cells were all normal. Moreover, all lymphocyte functions, including killer (K), natural killer (NK), cytotoxic T cell activity, helper activity for in vitro immunoglobulin (Ig) production by normal B cells, and PHA-induced proliferation were inhibitable by anti-LFA-1 monoclonal antibodies. K and NK activity mediated by patient leukocytes was 100-fold more sensitive to the inhibiting effect of anti-LFA-1 antibody than K and NK activity of normal donor leukocytes. Thus, although the amount of LFA-1 expressed was strongly reduced, it was still sufficient and required for the functional activity exhibited by patient T cells. The major functional defect observed with leukocytes of the patient and his father was an apparent B cell defect. B cells of the father and of the patient failed to produce Ig in the pokeweed mitogen (PWM)-driven system. The B cells of patient and of his father only produced Ig when cultured with T cells of the father, and not with normal donor T cells or T cells of the mother, in the presence of exogenous interleukin 2 (IL 2). In addition, the father's B cells produced Ig when cocultivated with patient T cells in the IL 2-driven system. This restriction of helper T cell activity is noteworthy because PWM- and IL 2-driven Ig synthesis by normal lymphocytes show no histocompatibility requirements between cooperating T and non-T cell populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Antigens, Surface↗
PubMed1983

[Assay of plasma fibronectin in clinical biology: comparison of nephelometric and turbidimetric technics].

The aim of this study was to determine the optimal conditions for the assay of plasma Fn by laser nephelometry, to compare the nephelometric and turbidimetric techniques and to confirm the influence of various parameters on the Fn concentration. The results reveal that both techniques are sensitive (threshold of sensitivity: 20 mg/l with laser nephelometry, 125 mg/l with turbidimetry), reproducible (coefficient of variation of less than 10 p. cent), specific, simple and rapid. The interpretation of the results must take into account the influence of various factors on the Fn concentration. Fn is present in lower concentrations in the serum and the percentage of serum Fn to the plasma concentration varies from one sample to another in the same patient. The optimal conditions for the assay include collection of the plasma on EDTA, storage of the samples at - 20 degrees C and incubation of the sample at 37 degrees C prior to the assay. There is a relationship between the concentration of Fn and the sex and age of the subject. There is a significant difference between the sexes between the ages of 18 and 40, which is no longer seen after the age of 50. The ability to assay plasma Fn by rapid, specific and sensitive techniques enables us to evaluate the capacity of response of the reticulo-endothelial system in conditions of severe sepsis.

Adult↗
PubMed1982

[Open study of bromapezan in ambulatory and psychiatric hospital patients (author's transl)].

Psychiatrists working in hospital and in private practice took part in co-operative trial aimed at evaluating the effectiveness and safety of bromazepam. The study was of the open type and involved 10 hospital patients and 20 ambulatory patients. The same protocole was followed for each patient. Twenty-five patients (including 5 in hospital) had anxiety neurosis; the remaining 5 had anxiety following weaning from alcohol. The anxiolytic effects of the drug, determined by means of Hamilton's anxiety scale and overall clinical judgement, were generally found to be satisfactory. The effective doses ranged from 1 to 3 tablets per day in ambulatory patients and from 3 to 5 tablets per day in hospital patients. The main side-effects were related to unwanted sedation; they only occurred with the higher doses and rarely interfered with the beneficial effects of bromazepam.

Adult↗
PubMed1982

Gangliosides in various brain areas of three inbred strains of mice.

The ganglioside patterns of cerebellum, cortex, pons-medulla, hypothalamus, hippocampus and caudate nucleus of three inbred strains of mice (C57BL/6J, DBA/2J and BALB/cJ) have been analysed. All brain areas contained both the simple and complex species of gangliosides. GD1a was the major ganglioside in cortex, hippocampus and caudate nucleus whereas GT1b was the major species in cerebellum, hypothalamus and pons-medulla. In hippocampus, the percentages of GT1b and GD1a were quite similar. Pons and medulla exhibited the highest levels of GM1 (which approaches the value of GT1b) and the lowest values of GD1a. A ganglioside, which was present in highest amounts in cerebellum disappeared after alkali treatment. Highly significant differences were observed in the amounts and patterns of gangliosides among brain areas of the three strains. Highly significant differences (p less than 0.001) were also found in the ganglioside distribution of various brain areas among the strains, especially for tri- and tetrasialogangliosides between Balb and DBA. A significant difference of GM1 was observed in the cerebellum when comparing DBA with the two other strains. It is likely that the differences might be related to their relative abundances in certain cell types and for defining synaptic circuits in brain areas of some strains.

Animals↗
PubMed1982

How different procedures of blood removal affect blood progesterone concentration in the cyclic female rat.

The effects of different procedures of blood removal on blood progesterone level were studied in female rats throughout the diestrous period of estrous cycle. Unoperated, sham operated, adrenalectomized and ovariectomized females were used. The complete manipulation comprising ether anaesthesia and blood collection lasted 3-4 min. Blood removal in itself did not exceed one minute. Blood progesterone levels appeared to be higher in unoperated, sham operated and ovariectomized females bled by heart puncture or from the abdominal vena cava under ether anaesthesia than in their decapitated counterparts bled without ether anaesthesia. Adrenalectomy prevented this effect from occurring. No difference in blood progesterone concentration was noted between anaesthetized and unanesthetized decapitated unoperated females. It was concluded that some procedures of blood removal under ether anaesthesia might cause a stress-related rise in blood progesterone concentration and that ether anaesthesia was not involved.

Adrenal Glands↗
PubMed1982

Enhancement of renal compensatory hypertrophy by hyperadrenocorticism and its modulation by nutritional factors.

Renal compensatory hypertrophy (RCH) is enhanced by ACTH in the uninephrectomized rat. In the present experiments, the kidney weight and its content in protein, RNA and DNA were determined in 48 adult, female rats; 24 had free access to a NaCl solution (9 g/l) and the others to a glucose solution (50 g/l). In each group 12 rats were sacrificed 2 or 7 d. after uninephrectomy (UN). In each subgroup 6 rats were treated with ACTH (18 micrograms/100 g B.W./d) from operation until autopsy. RCH has been evaluated by the arithmetical difference between the data determined in the right control kidney excised at UN and those determined in the left solitary kidney. In all the rats, hyperadrenocorticism increased significantly the weight of the solitary kidney and its content in protein and RNA. There was a significant decrease of the DNA content of the solitary kidney in the rats sacrificed 7 d. post-UN, treated with ACTH and drinking the saline solution. DNA was not affected by ACTH in the 7 other groups suggesting that ACTH favours cellular hypertrophy mainly in the rats drinking the saline solution. The renotrophic action of hyperadrenocorticism may be related to an altered handling of Na+ and K+: there was a positive correlation between the weight gain of the solitary kidney and the urinary excretion of Na+ (r = 0.507, p less than 0.001) and of K+ (r = 0.460, p less than 0.001). Hyperinsulinism was present in all the rats given ACTH; it may act as a growth factor. Hyperglycemia played an important role in former experiments but it was absent in the present studies.

Adrenocorticotropic Hormone↗
PubMed1982

[Frequencies of HLA-A, C and Bf antigens in schizophrenic patients originated from Alsace (author's transl)].

A comparison of the frequency of HLA-A, B, C and Bf antigens observed in a group of 75 chronic schizophrenics and in a control group of 184, all strictly from Alsace, does not carry any argument in favour of a strong genetic association between schizophrenia and the antigens studied. In effect, the modifications observed in the schizophrenic sample--decrease in the frequency of A10 and B5 antigens, and increase of A29 and BfF--are not statistically significant when the probabilities are multiplied by the number of tested antigens. These preliminary results however do not permit to exclude the possibility of an association between schizophrenia and the tested antigens.

Adolescent↗
PubMed1981

T lymphocyte characteristics in bone marrow-transplanted patients. II. Analysis with monoclonal antibodies.

The relative distribution of T cell subsets, as defined by the monoclonal antibodies OKT, was analyzed in peripheral blood lymphocytes of 8 children after bone marrow transplantation for aplastic anemia. The percentage of peripheral blood lymphocytes binding OKT3 (directed against a common T cell surface antigen and defining most peripheral T cells) reached normal values shortly after transplantation. In 5 patients, lymphocytes binding OKT8 (directed against an antigen present on the suppressor/cytotoxic T cell subset) were found in high proportion, and lymphocytes binding OKT4 (detecting an antigen present on inducer/helper T cells) in low percentage. This resulted in an inverted ratio OKT4/OKT8 compared with that of lymphocytes from normal individuals. In all patients the lymphocytes bound abnormally high amounts of OKT10 (directed against an antigen present on all thymocytes but not on mature peripheral T cells). In the course of time, a trend towards normalization was observed for all parameters investigated; however, the kinetics of the recovery showed a marked heterogeneity. From the analysis of this phenomenon, it is likely that, among other conditions yet unknown, a minimum of 20% of OKT4-positive lymphocytes is required for a normal proliferative response to T cell mitogens in vitro. No other correlation was found between any lymphocyte phenotype, as defined by the OKT antibodies, and proliferative response in vitro. Furthermore, lymphocytes from the patient with chronic graft-vs-host disease (greater than 50% OKT8 positive) failed to suppress the proliferative response to mitogens and antigens of the lymphocytes of the histo-identical bone marrow donor.

Antibodies↗