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C B Christensen

Publications and source records attributed to C B Christensen.

At least 19 recordsLinked to original sources
PubMed2001

[RTH syndrome--resistance to thyroid hormone syndrome].

The RTH syndrome is an instructive example of a receptor resistance syndrome. A typical case history is reported here. The patient had had symptoms for many years and was first diagnosed as having inappropriate secretion of TSH. Pituitary tumour was excluded. The primary symptom was palpitations and the patient was partially thyroidectomized many years ago on suspicion of thyrotoxicosis. She was then given substitutional Eltroxin, but, because of palpitations, the dose was reduced to almost zero, after which the patient contracted symptoms suggesting myxoedema. The thyroid values could not be used for clinical assessment, however the symptoms of myxoedema disappeared when the Eltroxin dose was increased to 75 micrograms/day. When the dose was increased further the heart symptoms became too troublesome. The patient had no signs of underlying heart disease.

Aged↗
PubMed2000

Molecular characterization of a Leishmania donovanii cDNA clone with similarity to human 20S proteasome a-type subunit.

Using plasma from patients infected or previously infected with Leishmania donovanii, we isolated a L. donovanii cDNA clone with similarity to the proteasome a-type subunit from humans and other eukaryotes. The cDNA clone, designated LePa, was DNA sequenced and Northern blot analysis of L. donovanii poly(A(+))mRNA indicated the isolation of a full length cDNA clone with a transcript size of 1.9 kb. The expressed recombinant LePa fusion protein induced proliferation of peripheral blood mononuclear cells in one out of seven patients who had suffered from visceral leishmaniasis. Plasma from 16 out of 25 patients with visceral leishmaniasis and four out of 18 patients with cutaneous leishmaniasis contained IgG antibodies which reacted with the purified LePa fusion protein as evaluated in an ELISA. The LePa DNA sequence was inserted into an eukaryotic expression vector and Balb/c mice were vaccinated. DNA vaccination of Balb/c mice with LePa generated an initial significant reduction in lesion size after challenge.

Animals↗
PubMed1997

Modification of T-cell antigenic properties of tetanus toxoid by SDS-PAGE separation. Implications for T-cell blotting.

Using Tetanus Toxoid (TT) as a model antigen the T-cell Blotting method was evaluated. Peripheral blood mononuclear cell (PBMC) cultures were stimulated by blotted nitrocellulose-bound TT or soluble TT. SDS-Poly-Acrylamide-Gel-Electrophoresis separated TT only induced proliferation in 20% of the PBMC cultures whereas proliferation was induced in 79% of the same cultures offered similar treated TT (except for the PAGE separation). When T-cell blotting was performed with TT separated in a SDS-agarose matrix, proliferation was induced in 80% of donors responding to soluble TT. The results show that SDS-PAGE alters the ability of TT to induce T-cell proliferation, possibly due to unpolymerized acrylamide binding to proteins during SDS-PAGE. The use of SDS-PAGE T-cell blotting in the screening for T-cell antigens must therefore be reconsidered. We suggest the use of SDS-Agarose Gel Electrophoresis as an alternative when doing T-cell blots.

Acrylamide↗
PubMed1997

Identification of porcine Pneumocystis carinii as a genetically distinct organism by DNA amplification.

DNA was amplified from lung samples from three piglets infected with Pneumocystis carinii, using oligonucleotide primers designed to the P. carinii mitochondrial large subunit ribosomal RNA gene. The nucleotide sequence of the amplification product was determined and indicated lack of sequence variation among these pig-derived P. carinii samples at this locus. The data showed that porcine P. carinii was genetically distinct from P. carinii isolated from other mammalian host species.

Animals↗
PubMed1996

Serodiagnosis of cutaneous leishmaniasis: assessment of an enzyme-linked immunosorbent assay using a peptide sequence from gene B protein.

An enzyme-linked immunosorbent assay (ELISA) using a 28 amino acid sequence of the repetitive element of gene B protein (GBP) from Leishmania major was developed for serodiagnosis of cutaneous leishmaniasis (CL). The assay was compared to ELISAs using crude amastigote and promastigote antigens from L. donovani and the major surface glycoprotein (Gp63) from either L. donovani or L. major as a solid-phase ligand. The sensitivity of the assays was tested in 33 patients suffering from CL caused by L. major. The sensitivity of the GBP peptide (GBPP) ELISA was 82%. This was higher than in the assays using crude amastigote (67%) or promastigote (67%) antigens, but the difference was not statistically significant. The sensitivity in the assays using Gp63 from L. donovani (52%) or L. major (39%) was significantly lower than in the assay using GBPP (P = 0.019 and P < 0.001, respectively). Plasma samples from healthy Sudanese individuals living in an area endemic for malaria but free of leish-maniasis were negative in all the assays. Significantly higher levels of antibodies were found in the patients who had suffered from the disease for more than eight weeks than in patients with a shorter clinical history (GBPP ELISA; P = 0.038; amastigote ELISA; P = 0.004; and promastigote ELISA; P = 0.017). In the former group, the sensitivities of the five ELISAs were 100% (GBPP), 87% (amastigote), 93% (promastigote), 67% (L. donovani), and 53% (L. major), respectively.

Adolescent↗
PubMed1995

The mu1, mu2, delta, kappa opioid receptor binding profiles of methadone stereoisomers and morphine.

The binding affinities of racemic methadone and its optical isomers R-methadone and S-methadone were evaluated for the opioid receptors mu1, mu2, delta and kappa, in comparison with that of morphine. The analgesic R-methadone had a 10-fold higher affinity for mu1 receptors than S-methadone (IC50 3.0 nM and 26.4 nM, respectively). At the mu2 receptor, the IC50 value of R-methadone was 6.9 nM and 88 nM for S-methadone, respectively. As expected, R-methadone had twice the affinity for mu1 and mu2 receptors than the racemate. All of the compounds tested had low affinity for the delta and kappa receptors. This result suggests that S-methadone does not essentially contribute to opioid effect of racemic methadone. R-methadone has a receptor binding profile which resembles that of morphine.

Animals↗
PubMed1995

Dichotomy of the T cell response to Leishmania antigens in patients suffering from cutaneous leishmaniasis; absence or scarcity of Th1 activity is associated with severe infections.

The T cell response was studied in 25 patients suffering from cutaneous leishmaniasis caused by Leishmania major with severe (n = 10) and mild (n = 15) disease manifestations. Peripheral blood mononuclear cells (PBMC) from the patients were activated by sonicates of Leishmania promastigotes (LMP) and amastigotes (LDA), and the surface protease gp63. The proliferative responses to Leishmania antigens were lower in patients with severe disease than in patients with mild disease (P = 0.01-0.05), and such a difference was not observed in the response to purified protein derivative of tuberculin (PPD) or tetanus toxoid (TT). LMP-induced interferon-gamma (IFN-gamma) production was lower in patients with severe than in patients with mild disease (P < 0.05). When the IL-4 and IFN-gamma responses of each patient were considered, two response patterns were observed in the cultures activated by the Leishmania sonicates. One response pattern was characterized by high production of IFN-gamma without production of IL-4 (a Th1-like pattern), the other was characterized by low IFN-gamma levels which in most cases were associated with IL-4 production (not a Th1-like pattern). These patterns could not be distinguished when the cells from the same donors were stimulated by TT and PPD. The percentages of patients with a Th1-like response pattern after stimulation by LMP in patients with severe and mild disease manifestations were 30% and 80%, respectively. This difference was statistically significant (P = 0.034).

Animals↗
PubMed1994

Dichotomy of the human T cell response to Leishmania antigens. I. Th1-like response to Leishmania major promastigote antigens in individuals recovered from cutaneous leishmaniasis.

The T cell response to antigens from Leishmania major promastigotes was investigated in peripheral blood mononuclear cells from Sudanese individuals with a history of cutaneous leishmaniasis (CL), Sudanese individuals with positive DTH reaction in the leishmanin skin test but with no history of skin lesions, and in Danes without known exposure to Leishmania parasites. Proliferation and production of interferon-gamma (IFN-gamma) and IL-4 in antigen-stimulated cultures was measured. Lymphocytes from individuals with a history of CL proliferated vigorously and produced IFN-gamma after stimulation with either a crude preparation of L. major antigens or the major surface protease gp63. These cultures produced no or only little IL-4. Also cells from leishmanin skin test-positive donors with no history of CL produced IFN-gamma and no IL-4 in response to L. major antigens. Cells from the unexposed Danes were not activated by gp63. The cells from Danish donors produced either IFN-gamma or IL-4, but not both cytokines after incubation with the crude preparation of L. major antigens. The data show that the T cell response to Leishmania antigens in humans who have had uncomplicated CL or subclinical L. major infection is an IFN-gamma-producing Th1-like response.

Animals↗
PubMed1994

Dichotomy of the human T cell response to Leishmania antigens. II. Absent or Th2-like response to gp63 and Th1-like response to lipophosphoglycan-associated protein in cells from cured visceral leishmaniasis patients.

The T cell response to different Leishmania donovani antigens was investigated using peripheral blood mononuclear cells (PBMC) from Kenyans cured of visceral leishmaniasis and non-exposed Danes. Crude promastigote and amastigote antigens both induced proliferation and interferon-gamma (IFN-gamma) production in PBMC from cured patients, while cells from non-exposed donors gave weak responses. A similar pattern was induced by lipophosphoglycan-associated protein (LPGAP). By contrast, the major surface protease of Leishmania, gp63, induced only a weak proliferative response without IFN-gamma production in five of 17 samples from cured patients. Four of the five responding cultures produced IL-4, i.e. the response to this antigen was of the Th2 type. Furthermore, sera from acutely ill visceral leishmaniasis patients contained high levels of IgG antibodies to gp63. The Th2-like response to gp63 in patients cured of visceral leishmaniasis differs from the Th1-like response to the same antigen observed in patients cured of cutaneous leishmaniasis.

Animals↗
PubMed1994

Morphine pharmacokinetics in premature and mature newborn infants.

The pharmacokinetics of a single dose of morphine was investigated in five term infants (gestational age 37-40 weeks) and eight preterm infants (gestational age 25-32 weeks). In the five term infants, median (range) volume of distribution at steady state (Vd beta) was 1758 (634-2700) ml/kg, plasma clearance (Cl) was 4.73 (1.75-6.61) ml/kg/min and terminal half-life (T1/2) was 224 (107-394) min. In the eight preterm infants, Vd beta was 2366 (1662-2876) ml/kg, Cl was 2.82 (1.88-6.60) ml/kg/min and T1/2 was 556 (248-834) min. No correlation was found between clearance and gestational age, but we found a significant negative correlation between T1/2 and gestational age. We conclude that there is considerable variation in the pharmacokinetic properties of morphine in both term and preterm newborn infants. Because of this variation, careful individual assessment of the clinical effect of therapy with morphine in newborn infants should be exercised.

Gestational Age↗
PubMed1994

Continuous reaction time after single dose, long-term oral and epidural opioid administration.

Auditory continuous reaction time was studied in three treatment groups. Twenty opioid naive patients received intramuscular morphine 0.15 mg kg-1 bodyweight for premedication. Thirty-one cancer patients were treated with oral opioids, 180 mg morphine per 24 h (median). Twenty-two cancer patients were treated with epidural morphine, 79 mg morphine per 24 h (median). The treatment groups were compared to a control group of 44 healthy persons taking no analgesics. The reaction time was measured using 152 auditory signals and summarized as 10%, 50% and 90% percentiles. Analysing reaction time distributions, the opioid naive patients showed the greatest difference to the control group in the shortest reaction times while chronic opioid users showed the greatest difference for the longest reaction times. There seems to be a qualitative difference in reaction time distribution, between opioid naive individuals treated with single dose morphine and cancer patients in long-term treatment.

Acoustic Stimulation↗
PubMed1993

Production of interferon-gamma and interleukin-4 by human T cells recognizing Leishmania lipophosphoglycan-associated protein.

The Leishmania protein LPGAP which is co-isolated with lipophosphoglycan is a specific activator of T cells from individuals who have recovered from American leishmaniasis. We have tested the effect of LPGAP on peripheral blood mononuclear cells (PBMC) from Kenyan donors cured from L. donovani infections. LPGAP induced vigorous proliferation and production of interferon-gamma (IFN-gamma) by the cells. In addition PBMC incubated with LPGAP released interleukin-4 (IL-4) after pulsing with ionomycin and phorbol myristate acetate. Single cells were isolated from LPGAP-stimulated cell lines and expanded as T-cell clones. LPGAP-reactive T-cell clones were activated by crude preparations of both promastigotes and axenic grown amastigote-like parasites. Among 9 CD4+ T-cell clones recognizing LPGAP, cells secreting predominantly IFN-gamma as well as cells secreting predominantly IL-4 were identified. The results show that both IFN-gamma producing (Th1-like) and IL-4 producing (Th2-like) T cells recognizing LPGAP are expanded after infection with L. donovani in humans.

Animals↗
PubMed1993

Myoclonic spasms during treatment with high doses of intravenous morphine in renal failure.

Myoclonic spasms occurred in a patient suffering from renal failure after high doses of continuous intravenous morphine (100 mg/h). The concentrations of morphine, morphine-6-glucuronide and morphine-3-glucuronide (mumol/l) in plasma were: 1.93, 52.06 and 381.8, and in cerebrospinal fluid were: 1.02, 5.86 and 61.82, respectively. The role of morphine and morphine glucuronides in myoclonic spasms is discussed.

Acute Kidney Injury↗
PubMed1992

Cellular and humoral immune responses in a population from the Baringo District, Kenya to Leishmania promastigote lipophosphoglycan.

In a cross-sectional house-to-house study in a leishmaniasis-endemic area in Kenya, the cellular and humoral immune response to Leishmania lipophosphoglycan (LPG) was determined. Clinical data, peripheral blood mononuclear cells, and plasma were obtained from 50 individuals over the age of eight years. Lymphoproliferation and interferon-gamma (IFN-gamma) production by these cells were examined. It was shown that cells from all six individuals in the population with a history of kala-azar responded to LPG in the lymphocyte proliferation assay, and four of these six responded in the IFN-gamma assay. In contrast, cells from 12 of 44 individuals from the study area with no history of kala-azar and none of the five Danish control samples responded to LPG. Antibodies against LPG were detected by enzyme-linked immunosorbent assay in 45 of 50 plasma samples. Our findings clearly show that mononuclear cells from kala-azar patients cured of infection were able to respond to the LPG preparation. The finding of a specific cellular immune response to LPG in 12 of 44 individuals with no history of kala-azar is consistent with previous epidemiologic studies, in which it has been shown that a proportion of L. donovani infections run a subclinical course. The high frequency of individuals with antibodies against LPG might indicate that a majority of the population had been exposed to the parasite.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗