Search PubMed⌕ Search

Biomedical subjects

I Nilsson

Publications and source records attributed to I Nilsson.

At least 109 records · Page 6Linked to original sources
PubMed1990

Fine-tuning the topology of a polytopic membrane protein: role of positively and negatively charged amino acids.

The effects of positively and negatively charged residues on the membrane topology of a model E. coli protein with two transmembrane segments have been studied. We show that addition or removal of as little as a single positively charged lysine residue in one of two critical regions can be sufficient to reverse the transmembrane topology of the molecule from Nout-Cout to Nin-Cin. Negatively charged residues are much less potent and significantly affect the topology only if present in high numbers. Finally, we provide data to suggest that sec-independent and sec-dependent translocation mechanisms differ in their sensitivity to positively charged amino acids.

Amino Acid Sequence↗
PubMed1990

Phase II clinical study of toremifene in patients with metastatic breast cancer. Preliminary communication.

Twelve postmenopausal women with inoperable or metastatic breast cancer were given toremifene at a daily dose of 60 mg. The patients had no prior endocrine or cytotoxic therapy and further inclusion criteria were bidimensionally measurable disease, performance status above 50, expected survival of more than 3 months and estrogen receptor status positive or undetermined. Objective response [complete remission (CR) + partial remission (PR)] was achieved in 6 patients (50%) and stable disease was obtained in 5 patients. No side effects of the treatment were noted.

Aged↗
PubMed1990

Phase II clinical study of high-dose toremifene in patients with advanced breast cancer.

Thirteen postmenopausal women with advanced local or metastatic breast cancer were treated with the antiestrogen toremifene at a daily dose of 200 mg. All patients had failed previous treatment with different types of endocrine therapy and/or cytotoxic drugs. Objective response was only seen in one patient. Treatment was usually well tolerated but in three cases the drug had to be withdrawn due to side effects.

Adult↗
PubMed1990

New microsurgical suction tubes.

A set of new suitable microsurgical suction tubes has been designed especially suitable for fragile and delicate tissues such as the nervous and vascular tissues in the brain and spinal cord. The set provides two different shafts and five different tubes for superficial of deep micro- as well as macro-operations. These new suction tubes have two major advantages compared to traditional suction tubes. Firstly: the perforated smooth suction-tip allows continuous suction without damage to the tissue and secondly: the tubes are quickly and easily exchanged from the suction shaft when necessary.

Equipment Design↗
PubMed1990

Detection of antibodies to Helicobacter pylori cell surface antigens.

Serum IgG antibodies of Helicobacter pylori were detected in single-dilution ELISA using glycine extracted material. Among 148 endoscopy patients 59% displayed antibodies; as expected, a higher occurrence (90%) was found in patients with positive gastric culture for H. pylori than in culture negative patients (37%). Among 68 blood donors the frequency of H. pylori antibodies was 28%. In 73 children less than 15 years of age examined for unrelated disorders the occurrence was 4%. By immunoblotting using the same extract, 3 prominent bands, 29K, 54K and 60K and several weak bands were identified. These were formed by 57%, 92%, and 65%, respectively, of the ELISA positive patient sera. Comparing culture positive and negative patients, the 3 bands occurred more often among the culture positive subjects though between 18 and 61% of the sera from culture negative patients gave either of the bands. When comparing the glycine extracts of 4 different H. pylori strains with separate haemagglutinating patterns no differences in the position of the major bands emerged. By absorption experiments no immunological cross-reactivity with components of Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni or C. fetus was found. Thus, the glycine extract seemed specific for the detection of antibodies to H. pylori.

Antibodies, Bacterial↗
PubMed1990

Prevalence of protein-energy malnutrition in a large population of elderly people at home.

The prevalence of protein-energy malnutrition (PEM) was examined in 1206 randomly selected elderly people aged 65 to 80 years living in their own homes. Nutritional assessment was based on weight loss, weight index, triceps skin fold, arm muscle circumference, serum albumin and prealbumin, and delayed cutaneous hypersensitivity (DCH) reaction. The prevalence of PEM was 5 per cent. If people with signs of inflammation were excluded, the prevalence of PEM was 3.5 per cent. When other nutritional indices, used by other authors among hospitalized patients, were applied to our sample prevalence values from 2.6 to 4.1 per cent were obtained. the prevalence was not related to sex or age. DCH increased the sensitivity of the screening method but causes of anergy other than PEM must be taken into account. It is concluded that PEM, in a degree shown to impair the prognosis at hospital, does occur among elderly people at home in an industrialized country.

Aged↗
PubMed1989

Diagnostic significance of dysplastic features of peripheral blood polymorphs in myelodysplastic syndromes.

Dysplastic features of peripheral blood granulocytes were studied to investigate the diagnostic value estimating cytoplasmatic hypogranulation and nuclear abnormalities of the pelgeroid type in myelodysplastic syndromes (MDS). Hypogranulation was measure both as the percentage of agranular neutrophils and as a score value, taking into account also cells with slight or moderate hypogranulation. We studied 62 cases of MDS (18 refractory anemia, 11 sideroblastic anemia, 26 refractory anemia with excess of blasts, three chronic myelomonocytic leukemias, four refractory anemia with excess of blasts in transformation). For comparison we studied 13 cases of myeloproliferative disorders, 18 patients with different forms of anemia and 20 normal controls. Reference values were defined as the 95% probability limit of the mean values of normal controls. In MDS 52/62 patients (84%) had increased numbers of pelgeroid cells, 40/62 (65%) had abnormal granulation scores while only 14/62 (23%) had increased percentages of agranular neutrophils. The mean granulation score (+/- S.D.) in MDS (225.0 +/- 57.4), was significantly lower (p less than 0.001) than in myeloproliferative disorders (282.7 +/- 9.0), anemias (288.8 +/- 8.0) and normal controls (281.7 +/- 12.9). Pelgeroid neutrophils were significantly (p less than 0.001) more common in MDS (11.6% +/- 7.8) compared to myeloproliferative disorders (1.1% +/- 1.0), anemias (3.1% +/- 2.0) and normal controls (1.9% +/- 1.5). There was no significant correlation between the degree of hypogranulation and the percentages of pelgeroid cells in individual patients. Hypogranulation tended to be more pronounced in the more immature forms of MDS while pelgeroid cells were equally common in the different subgroups. When the two parameters were combined peripheral blood dysplasia was recognized in 92% of the MDS cases. The results suggest that quantitative estimation of hypogranulation and of nuclear abnormalities in peripheral blood polymorphs are simple and valuable diagnostic tools in MDS.

Aged↗
PubMed1989

Resolved 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8-amine: central dopamine and serotonin receptor stimulating properties.

The enantiomers of 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8- amine (1a) were prepared and tested for their actions on central dopamine and serotonin (5-HT) receptors. The dopaminergic effects were shown to reside in the (1)-R enantiomer. It was shown that compound 1a and its (+)-R enantiomer possess potent central 5-HT1A receptor stimulating properties.

Animals↗
PubMed1989

Toxin production by Bacillus cereus dairy isolates in milk at low temperatures.

A total of 136 strains of Bacillus cereus isolated from milk and cream were evaluated for toxin production based on HeLa S3, Vero, and human embryonic lung (HEL) cell cytotoxicity in vitro. HEL cell monolayers were more susceptible than the other two cell lines. The percentage of isolates exhibiting HEL cytotoxicity was similar (43.0 and 48.4%) when the strains were grown in brain heart infusion broth containing 0.1% glucose (BHIG) at 7 and 24 h, respectively, at 30 degrees C. In milk, only 21.8% of isolates showed HEL cytotoxicity at 7 h, and the number increased significantly to 73.2% at 24 h at 30 degrees C. Further, 102 toxin-positive isolates were acclimatized to grow at 8 degrees C in milk. Ninety-four (92.2%) of the strains produced HEL cytotoxicity of various degrees with no strict correlation to bacterial cell numbers and also elicited vascular permeability reaction in rabbit skin. Under aerated growth conditions (agitation, 200 rpm) B. cereus elicited cytotoxicity in BHIG and in milk at temperatures of 30, 15, and 8 degrees C. However, in nonaerated (stagnant) cultures toxin production was diminished (BHIG) or completely lost (milk) at all temperatures. Toxin production at 8 degrees C was evaluated in two different types of commercial cardboard milk packages by inoculation with a potent toxigenic dairy isolate. No detectable HEL cytotoxicity was observed in milk in any of the packages either at stagnant conditions or during mechanical shaking. However, the same strain produced cytotoxin in whipped cream at 8 degrees C.

Aerobiosis↗
PubMed1989

Radical radiotherapy in prostatic carcinoma.

During the years 1978-1986 111 fairly elderly patients with prostatic carcinoma in clinical stages B, C, or D, and usually having tumours that were poorly differentiated, received radical radiotherapy to the prostate and bladder and to the adjacent lymph node regions. The side effects were comparable to those reported in the literature. During the follow-up 72% of the patients sooner or later (actuarial analysis) developed local recurrence or distant metastases. The projected survival rate at 8 years was 25%, and should be compared with the 65% expected for an age-matched Swedish male population. After 3 years the two survival curves became rather parallel, indicating a 'cure' rate of the order of 49%. There was a significant difference in survival between patients clinically judged to have only intracapsular carcinoma and those considered to have extracapsular carcinoma. The relatively modest survival figures in the present series reflect the malignant nature of poorly differentiated carcinoma of the prostate.

Aged↗
PubMed1988

Proliferation of Schwann cells in a developing feline lumbar ventral spinal root.

Schwann cell proliferation in the L6 ventral spinal root of cat fetuses and young kittens was studied by light microscopical autoradiography and electron microscopy. The proliferative activity reached a maximum 35 days after mating. This is about one week before the immature alpha-axons begin to myelinate and about one month before birth (63 days after mating) when the myelination of the immature gamma-axons starts. The proliferative activity was already quite low 45 days after mating and ceased completely after birth. Calculations based on the observed number of Schwann cell nuclei per 100 axons showed that the number of Schwann cells already present 45 days after mating was equal to or even a little higher than the observed adult number. Necrotic nucleated Schwann or endoneurial cells were not observed. I conclude that Schwann cell proliferation in the L6 ventral spinal root is already nearly finished when the first immature alpha-axons begin their myelination and that myelination of the immature gamma-axons begins without a preceding increase in Schwann cell proliferative activity.

Aging↗
PubMed1988

Axon classes and internodal growth in the ventral spinal root L7 of adult and developing cats.

Internodal length, number of myelin sheath lamellae and axon diameter were estimated in samples of nerve fibres reconstructed from transverse sections (EM and LM) of the L7 ventral spinal root of adult cats, kittens and cat fetuses. The axon calibre spectrum was unimodal in the youngest fetuses, became bimodal at 47 days after mating, i.e. about 2 weeks before birth (63 days after mating) and trimodal at 1 week of postnatal age. Alpha-axons received myelin during the period 40-45 to 50-55 days after mating while gamma-axons became myelinated from 60-63 days after mating to 2-3 weeks of postnatal age. The mean length of the first completely myelinated internodes measured 139 microns and 209 microns in the alpha- and gamma-fibre group respectively. The adult mean values were 1390 microns and 640 microns respectively. The average internodal elongation was x 10 and x 3 in the two fibre groups, whereas the longitudinal growth of the whole ventral root was x 5.4 and x 3.5. A combined linlog function could be fitted to describe the regression between internodal length and axon diameter and was established from birth onwards. The separate alpha- and gamma-fibre samples were best described by linear functions, the alpha internodal length being independent of axon diameter while the gamma internodal length increased linearly with axon diameter. The amount of internodal myelin increased linearly with increasing mantle area of the internodal axon. The mean amount of internodal myelin of alpha-fibres showed two periods of intense growth; one from the start of myelination to 2 months postnatally and the other between 4 and 6 months of age. The mean length of the lamellar spiral forming the myelin sheath showed about the same increase per unit length of axon circumference (about 160:1) in both alpha- and gamma-fibre groups as long as longitudinal internodal growth persisted.

Age Factors↗
PubMed1987

Redistribution of Schwann cells in developing feline L7 ventral spinal roots.

The length and distribution of Schwann cells along fibres in the ventral root L7 of the developing cat have been studied electron microscopically in serial sections. The average Schwann cell length at the beginning of myelin formation - the 'initial internodal length' - was 118 micron (110 micron in alpha-axons and 124 micron in gamma-axons). The number of Schwann cells found in a fully developed root segment was already present at the beginning of the myelination. It showed no systematic age-dependent variation from the beginning of myelination to adulthood. The Schwann cells associated with alpha-axons increased their length 12.6 times during this period, while the root elongated 5.6 times. About 50% of the Schwann cells had to be eliminated in order to make the elongation of the remaining Schwann cells possible. Corresponding calculations from the mean length of Schwann cells associated with gamma-axons, showed that about 50% too few Schwann cells were associated with the gamma-axons during the period of initial myelination of the alpha-axons. At birth, when the myelination of gamma-axons had just begun, both the large surplus along alpha-axons and the deficit along gamma-axons had disappeared. We suggest that Schwann cells are eliminated from the alpha-axons and re-utilized along the gamma-axons. During this process of cellular redistribution, affected cells constitute so-called aberrant Schwann cells.

Age Factors↗
PubMed1985

Immunoglobulin G antibodies binding to a synthetic peptide deduced from the nucleotide sequence of the env gene of HTLV I in patients with leukemia and rheumatoid arthritis, HLA sensitized persons and blood donors.

A synthetic pentadecapeptide preparation, env 406-420, with an amino acid sequence deduced from the envelope glycoprotein gene of human T cell leukemia virus type I (HTLV I), was used as the antigen in an enzyme immunoassay for immunoglobulin G antibodies, exploring its usefulness for seroepidemiological purposes. The frequency of reactivity in the test groups, presented in decreasing order was: patients with rheumatoid arthritis; multitransfused nonleukemic patients; Japanese cases of adult T cell leukemia (ATL); HLA sensitized persons; Swedish cases of adult acute leukemia; and Swedish blood donors. Three American cases of ATL and 12 HTLV I seropositive monkeys did not react. In RF positive sera from patients with rheumatoid arthritis, no quantitative correlation between RF activity and anti-env 406-420 activity was seen. Anti-env 406-420 positive sera did not react or reacted only weakly with four control peptide preparations with different amino acid sequences. The experience with oligopeptide serology still is limited. Our results illustrate that unexpected cross-reactions which are hard to interpret can occur. Although absorption experiments indicated an HTLV I specific component of the reactivity, antibodies against epitopes of allo- and auto-immune specificity may also have participated.

Arthritis, Rheumatoid↗