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Biomedical subjects

N Olsen

Publications and source records attributed to N Olsen.

At least 55 records · Page 3Linked to original sources
PubMed1987

Centrally and locally mediated vasomotor activities in Raynaud's phenomenon.

A selective review on the attack of Raynaud's phenomenon in primary Raynaud's phenomenon and vibration-induced white finger is presented with special reference to the location of the primary vasospasm, the nature of the dominant pathophysiological mechanism, and the anatomic location of the abnormal link in this mechanism. It is suggested that the primary vasospasm is a total closure of the main digital arteries, that the arterial spasm is mainly mediated through an exaggerated central sympathetic reflex mechanism, and that the abnormal link in this reflex arch could be the smooth muscle cells of the digital arteries. Other anatomic locations of the abnormal link can however not be excluded as yet.

Fingers↗
PubMed1985

Sympathetic and local vasoconstrictor response to cold in vibration induced white finger.

To study the relative roles of sympathetic and local vasoconstrictor response to cold in vibration induced white finger (VWF) seven lumberjacks with bilateral VWF and seven age matched controls were investigated. During body cooling finger systolic blood pressure was measured with a cuff technique simultaneously on one affected finger on each hand at 30 degrees, 15 degrees, and 6 degrees C. Both affected fingers had an increased vasoconstrictor response at 15 degrees and 6 degrees C compared with the control group (p less than or equal to 0.05). During unilateral sympathetic nerve block the cold provocation test was repeated on both fingers. The unblocked finger affected by VWF showed no significant difference in the cold response between the two cold provocation tests (p greater than 0.10). The local cold response of blocked finger did not differ from that of the control group (p greater than 0.10). The sympathetic vasoconstrictor response to cold was estimated as the difference between the cold response before nerve block and the cold response during nerve block. The median sympathetic vasoconstrictor response at 6 degrees C was about twice as large as the local response during nerve block (p less than 0.05). The results indicate that the sympathetic vasoconstrictor response to cold plays the dominant part in VWF.

Aged↗
PubMed1984

Human IgG aggregates induce selective stimulation of IgM rheumatoid factor synthesis by rheumatoid blood mononuclear cells.

Peripheral blood mononuclear cells (PBM) from patients with active rheumatoid arthritis (RA) contain precursor B lymphocytes specific for IgM rheumatoid factor (IgM-RF) synthesis. In this study, human IgG aggregates (HaIgG) were used to stimulate monocyte-depleted PBM from 46 patients with RA and 21 normal controls. The cells were incubated with HaIgG and pokeweed mitogen for 72 hours, washed, and then cultured in microwells for an additional 11 days. HaIgG induced an increase in IgM-RF synthesis by RA cells with optimum response at 0.1 microgram/ml (P less than 0.001). Total IgM synthesis remained unchanged. In contrast, HaIgG did not stimulate IgM-RF production by normal cells. Specificity of the IgM-RF response was shown by the concomitantly increased IgM-RF/IgM ratios, while IgM anti-trinitrophenyl antibodies did not increase. Aggregation of the IgG was required for it to be an effective stimulus. The findings suggest that circulating immune complexes in RA patients may provide the stimulus for sustained production of IgM-RF in vivo.

Arthritis, Rheumatoid↗
PubMed1984

Spontaneous synthesis of IgM rheumatoid factor by blood mononuclear cells from patients with rheumatoid arthritis: effect of treatment with gold salts or D-penicillamine.

Spontaneous IgM rheumatoid factor (sIgM RF) synthesis in vitro by blood mononuclear cells (BMC) from rheumatoid arthritis (RA) patients has been previously shown to correlate with disease activity. Ten active RA patients were studied prior to and after the start of therapy with gold salts or penicillamine. sIgM RF decreased steadily over the period of study and was strongly correlated with mean joint count (r =0.94, p less than 0.001), erythrocyte sedimentation rate (r = 0.90, p = 0.014), and duration of morning stiffness (r = 0.78, p = 0.068). In 9 patients with significant decreases, mean sIgM RF was 8% of the initial value after 9 weeks of treatment. The decrease in sIgM RF was relatively specific since the ratio of sIgM RF to total spontaneous IgM synthesis (sIgM) declined during the treatment period. The results indicate that changes in sIgM RF constitute a sensitive indicator of disease activity and response to therapy in RA.

Adult↗
PubMed1983

Difference in systolic blood pressure between arm arm and ankle region in children 0-15 years old.

Arm and ankle systolic blood pressure was measured in a supine position in 95 children aged between 2 days and 16 years using either the ultrasound Doppler technique (0-6 years) or the strain-gauge technique (7-16 years). Among children below 1 year of age, the ankle systolic blood pressure was significantly lower than the arm blood pressure and lowest when recorded over the dorsal pedal artery as compared to the post-tibial artery. Children over 1 year of age had a higher ankle systolic blood pressure compared to the arm which corresponds to earlier findings among adults. The study indicates that lower limb systolic pressure is greater than upper limb systolic pressure but first demonstrable at the time when the babies begin to stand or walk. These findings might be used in evaluation of children suspected for aortic coarctation.

Adolescent↗
PubMed1983

Regional scintimetry in scaphoid fractures.

A quantitative scintigraphic method was introduced to examine the proximal, middle and distal third of the carpal scaphoid bone. 99mTc-Sn-pyrophosphate scintimetry was obtained by the use of a gamma camera equipped with a pinhole collimator. Of six patients in whom a unilateral fresh fracture of the scaphoid was clinically suspected, radiology showed a fracture of the scaphoid in four and no fractures in two. The method may be suitable in early diagnosis and further localization of clinically suspected fractures with initially non-diagnostic radiographs.

Adolescent↗
PubMed1982

In vitro synthesis of immunoglobulins and IgM-rheumatoid factor by blood mononuclear cells of patients with rheumatoid arthritis.

In vitro synthesis of IgG, IgM and IgM-rheumatoid factor (IgM-RF) was investigated in unstimulated and pokeweed mitogen (PWM)-stimulated 7-day cultures of blood mononuclear cells (BMC) from 28 seropositive patients with active rheumatoid arthritis (RA), in a second group of 13-day cultures from 94 unselected rheumatoid patients, and in 21 healthy controls. Both normal and rheumatoid BMC cultures synthesized IgM-RF in response to PWM stimulation. Mitogen-induced stimulation was shown to be dependent on the presence of T-lymphocytes. PWM-induced IgM and IgM-RF synthesis were reduced in BMC from rheumatoid patients in comparison with healthy controls. However, the fraction of IgM-RF in the total IgM synthesized was significantly higher in the RA supernatants than in the controls, suggesting the presence of a larger precursor B-cell population committed to IgM-RF synthesis in those cultures. BMC from 44 of the 94 patients demonstrated spontaneous synthesis of IgM-RF, and this was positively correlated with disease activity and rheumatoid factor titer. Spontaneous production was shown to reside in the T-lymphocyte depleted, adherent cell-depleted, B-cell subpopulation. It is concluded that in active RA there is a specific activation and expansion of the circulating B-cell subpopulation committed to IgM-RF synthesis, possibly due to abnormal immunoregulatory mechanisms modulating synthesis of this antibody.

Adult↗
PubMed1980

Thermostatted measurement of systolic blood pressure on cooled fingers.

Indirect recording of systolic blood pressure on fingers was performed after local cooling using a double-inlet plastic cuff on one phalanx. Cooling induces constriction of the digital arteries and the delayed re-opening during cuff deflation is recordable by the decrease in finger systolic pressure. A new device for rapid thermostatic equilibration using Peltier elements is described. The method was applied to three groups of normal subjects: seventeen indoor working females, sixteen indoor working males and twenty working males. After mild body cooling the finger systolic pressure was decreased on average to 88% in all three groups at a finger temperature of 15 degrees C (95% lower confidence limit 68%). Young females with complaints of cold hands or Raynaud's phenomenon had significantly lower pressures and the method is therefore applicable for routine investigations.

Adolescent↗
PubMed1980

Cold hypersensitivity after sympathectomy for Raynaud's disease.

Two patients with socially handicapping Raynaud's disease underwent bilateral upper thoracic sympathectomy. One to two days after the operation, both developed local hypersensitivity to cold in the form of a rebound. The cold hypersensitivity persisted in one of the patients, although complete degeneration of vasoconstrictor fibres was proven by absence of the sympathetic veno-arteriolar reflex after sympathectomy. Pre-operative sympathetic blockade could not predict the outcome of sympathectomy.

Adult↗
PubMed1980

Raynaud's phenomenon: peripheral catecholamine concentration and effect of sympathectomy.

The reaction to body and finger cooling was recorded in seven patients with relapse of primary Raynaud's phenomenon after sufficiently performed bilateral upper thoracic sympathectomy and for comparison in eight young women with primary Raynaud's phenomenon as well as in seven normal women. The forearm venous concentration of noradrenaline was lower and adrenaline concentration higher in the sympathectomized patients than in the other groups (p less than 0,05). Noradrenaline showed a significant increase during body cooling in normals and primary Raynaud's (p less than 0,05). There was no significant correlation between the vasoconstrictor response to cooling of a finger and the noradrenaline concentration probably due to the fact that skin vasoconstriction impeded release of noradrenaline from the skin. The relapse of Raynaud's phenomenon after surgically sufficient sympathectomy could not be treated by reserpine or alfa-adrenergic receptor blockers in two patients in whom this was tried.

Adult↗
PubMed1980

Bacterial endocarditis caused by vitamin B6-dependent viridans group Streptococcus.

Two cases of bacterial endocarditis in children, caused by viridans group Streptococcus which requires vitamin B6 or thiol compounds for growth are reported. It is important to recognize these organisms as a possible cause of endocarditis because supplemented media are needed for their isolation and sensitivity testing. These organisms may be penicillin-sensitive, -resistant, or -tolerant. An organism is considered tolerant to an antibiotic when the minimum bactericidal concentration of that antibiotic is greater than or equal to 32 times the minimum inhibitory concentration. One of our patients relapsed when treated with a single antibiotic to which the B6-dependent viridans group Streptococcus was tolerant. If a B6-dependent viridans group Streptococcus is isolated from a patient with endocarditis, therapy should be initiated with penicillin and an aminoglycoside until sensitivities are available. Sensitity testing should include both the MIC and MBC and adequate therapy can be confirmed by determing the serum bactericidal activity.

Adolescent↗
PubMed1978

Prevalence of primary Raynaud phenomena in young females.

A questionnaire concerning Raynaud's phenomenon was sent to eighty-five females (aged 21--50 years) working as physical therapists at municipal hospitals in Copenhagen. Fifteen of sixty-seven healthy young females (22%, 95% confidence limits 13--34%) were classified as having Raynaud phenomena in its primary form. Twenty-four persons underwent a detailed clinical investigation with measurement of blood pressure at the arm and fingers with cuff techniques. Cold provocation test on one finger was carried out after moderate body cooling. Of eight subjects being classified from the questionnaire as having Raynaud phenomena, six showed closure of the digital arteries at the local cold provocation, and all had an exaggerated response. A group complaining of cold fingers showed a greater reduction in finger blood pressure during local cooling than the normal group, but none showed closure. A questionnaire can separate the groups if Raynaud phenomena is defined by appearance of white and dead fingers on cold exposure with frequent cold or bluish fingers.

Adult↗
PubMed1978

Cimetidine treatment of protein-losing gastropathy (Ménétrier's disease). A clinical and pathophysiological study.

In a 47-year-old male with Ménétrier's disease (protein-losing gastropathy) the histamine-H2-receptor antagonist Cimetidine stops the protein loss and improves the clinical condition. Gastric perfusion studies on net and bidirectional ionic fluxes, protein secretion rates, and permeability, with simultaneous recording of the transmural electrical potential difference indicate that Cimetidine decreases a paracellular protein secretion by 'tightening' the tight junctions of the gastric epithelium.

Cimetidine↗