Neonatal reference values for ionized calcium, phosphate and magnesium. Selection of reference population by optimality criteria

Thirty-one full-term newborn babies were investigated in order to establish reference values for ionized calcium. Only children fulfilling certain optimality criteria (with best possible maternal and infant conditions and uncomplicated pregnancy and delivery) were included. All infants were breast fed. Capillary blood for analysis of ionized calcium was collected by heel puncture on day 1 (6-36 h post partum, p.p.), day 3 (60-84 h p.p.) and day 5 (108-132 h p.p.). Ionized calcium was measured with a semi-automatic electrode system ICA 1 (Radiometer A/S, Copenhagen, Denmark). The reference ranges (mean +/- 2 SD) for days 1, 3 and 5 were 1.05-1.37, 1.10-1.42 and 1.20-1.48 mmol/l, respectively. The mean ionized calcium concentration on day 1 was significantly lower than on days 3 and 5. Reference values are also given for total calcium, magnesium and phosphate. We emphasize that it is impossible to calculate ionized calcium from total calcium or vice versa.     

Holding power impaired in rheumatoid femoral heads. Cadaveric study of fracture fixation devices

A measurement was made of the holding strength and the energy needed to extract a NoLok hip screw, a von Bahr screw, and a Hansson hookpin from cadaveric femoral heads. The specimens were obtained from female subjects aged 65 years or more, with 36 specimens each from rheumatoid (RA) and nonrheumatoid (non-RA) donors. Retraction of the implants was made by a continuous uniaxial pullout at 10 mm/min. For each type of device, the holding strength in rheumatoid femoral heads was less than in non-RA specimens. In rheumatoid specimens the maximum holding strength for the NoLok screw (1,622 N) was higher than that of the other two devices, whereas the von Bahr screw (1,177 N) had a higher maximum holding strength than the Hansson hook-pin (603 N). In non-RA, there was no difference in maximum holding power between the NoLok screw (2,549 N) and the von Bahr screw (2,282 N); however, both had a higher holding strength than the Hansson hook-pin (851 N). A rapid fall off was experienced in the force required to continue extraction of both types of screws, whereas for the Hansson hook-pin the strength decreased slowly. For each type of device, the energy needed for extraction of the implant was less in the RA group femoral heads, while there were no differences in total extraction energy between devices.     

Functional evaluation of the spinal cord by magnetic resonance imaging in patients with rheumatoid arthritis and instability of upper cervical spine

Thirty-four patients with atlanto-axial instability due to rheumatoid arthritis were examined with plain x-ray views and functional magnetic resonance imaging (MR), and were neurologically evaluated. Transcranial brain stimulation was performed in 25 patients. In 22 cases, the authors observed inflammatory tissue thicker than 3 mm behind the odontoid peg. The spinal canal diameter was significantly decreased in the flexed position. Nine patients showed signs of cranial migration of the axis. The diameter of the spinal cord was measured to be 7.4 mm in the neutral position, and 6.5 mm in flexion. The difference between the diameter of the neutral and flexed positions was highly significant. Twelve of the 34 patients displayed clinical signs of cervical myelopathy, and 13 showed a significant delay of central motor latency, as calculated from the motor evoked potentials. Surgical intervention, either by a posterior approach only or combined with a transoral dens and inflammatory tissue resection, is recommended in patients with progressive atlanto-axial instability, pathologic clinical and neurophysiologic findings, and a spinal cord diameter of less than 6 mm in flexion. Severe pain and cranial migration of the axis, as measured by the MRI, also justify a surgical intervention.     

Regulation of the delayed hypersensitivity reaction in the lung reflected as mononuclear, mast cell and mucus cell appearance after T helper cell depletion and adoptive transfer

Epicutaneous sensitization with picrylchloride (PiCl) induced a strongly delayed hypersensitivity (DH) reaction in mice. Local challenge in the airways of these mice resulted in increased numbers of mononuclear cells, mast cells and mucus cells. Depletion of T helper cells in vivo by treatment with monoclonal antibody (GK 1.5) inhibited the DH reaction. This treatment also resulted in a decrease in the number of mononuclear and mucus cells in the lung after intranasal challenge. The DH reaction was transferred to recipients with immune lymph node cells and spleen cells from mice sensitized epicutaneously with PiCl. The recipient mice also showed a slight increase in the number of mononuclear cells in the lung after intranasal challenge. These results indicate that T cells are not only involved in the DH reaction but also in the accompanying lung reaction.