The safety of dental mini-magnets in patients with permanent cardiac pacemakers.

To evaluate the safety of prosthetic mini-magnets, 12 patients treated with implanted cardiac pacemakers were examined. Small cylindric magnets were applied one, two, and three at a time to constant points on the pacemaker under electrocardiographic monitoring. No influence on the pacemaker was detected in nine of the patients, but limited changes were encountered in three patients. However, the changes disappeared when the magnets were moved 1 cm away. The conclusion was that the use of mini-magnets in dental care in patients with implanted pacemakers is safe and acceptable.

Serum and mononuclear cell potassium, magnesium, sodium and calcium in pregnancy and labour and their relation to uterine muscle contraction.

Thirty women in their third trimester of pregnancy (37-42 weeks), 40 women during and 72 h after labour and 18 non-pregnant controls were studied for changes in serum and mononuclear cell cation content, and their relationship to cervical effacement and intensity of pain as measured by plasma beta endorphin concentrations during labour. Serum magnesium fell from 0.95 +/- 0.01 (mean +/- SEM) to 0.84 +/- 0.02 mmol/litre at late pregnancy and further to 0.76 +/- 0.01 during labour (P < 0.001); serum potassium fell from 4.25 +/- 0.05 to 3.79 +/- 0.06 mmol/litre (P < 0.0001) during labour; and serum calcium fell from 2.40 +/- 0.02 to 2.28 +/- 0.01 mmol/litre at late pregnancy (P < 0.001) and further to 2.25 +/- 0.02 mmol/litre during labour (P < 0.001). Mononuclear cell magnesium content rose from 4.5 +/- 0.3 to 5.6 +/- 0.04 fmol/cell (P < 0.02); potassium content rose from 37.7 +/- 2.0 to 50.9 +/- 3.0 fmol/cell (P < 0.001); and calcium content rose from 4.4 +/- 0.4 to 7.6 +/- 1.1 fmol/cell (P < 0.105). On the other hand, mononuclear cell sodium content fell from 7.2 +/- 0.5 to 3.8 +/- 0.3 fmol/cell (P < 0.001). Plasma beta endorphin concentrations increased with increasing degrees of effacement, as did intracellular Na, whereas intracellular Mg and K showed an inverse trend. A significant correlation was found between intracellular cation and beta endorphin levels (r = -0.98, Mg; -0.99, K; 0.83, Na). These changes are probably due either to intercompartmental cation shifts or possibly to endometrial ischaemia and damage during labour.

Serum and intracellular electrolytes in patients with and without pain.

The effect of acute stress, with and without pain, on serum and mononuclear cell cation content was studied in 205 healthy women in their last trimester of pregnancy or during normal labour, in patients with acute medical conditions in which pain was or was not present, in acute surgical conditions, and immediately prior to elective surgery. In all subjects there was a fall in serum sodium, potassium, magnesium and calcium concentrations during stress, with an apparent shift into the intracellular space. An inverse correlation was present between the severity of pain and the fall in serum cations.

The rise of serum creatinine levels during labor.

Serum creatinine, blood urea nitrogen and creatine phosphokinase were measured in 32 women during the last 3 weeks of pregnancy and, in a further 39 women, during and after labor. The serum creatinine increased from 61.9 +/- 0.9 to 69.8 +/- 1.8 mumol/l (mean +/- SEM) (P less than 0.05) in the third stage of labor and returned to normal by 72 h after delivery. The muscle creatine phosphokinase increased from 54 +/- 7 to 77 +/- 9.9 units (P less than 0.05) during the third stage and remained high (87 +/- 13.3 units) 72 h later. We conclude that these changes are due to muscle contraction and injury during delivery.

The relationship between beta-endorphin levels and uterine muscle contractions during labor.

Plasma beta-endorphin (BE) levels (8.6 +/- 0.8 pmol/l) (mean +/- SE) were lower in the third trimester than in non-pregnant controls (14.8 +/- 1.1 pmol/l) (P less than 0.001), increased during labor, to 29.3 +/- 4.4 pmol/l (P less than 0.005) and decreased, 72 h after delivery, to 3.5 +/- 0.4 pmol/l (P less than 0.001). BE levels were found to correlate significantly with uterine muscle contraction (r = 0.966, P less than 0.05) and with cervical effacement (r = 0.974, P less than 0.05) during labor.

A routine method for the measurement of the sodium, potassium, magnesium and calcium content of human lymphocytes.

We describe a rapid, single-step procedure for the isolation of human lymphocytes from whole blood, suitable for a routine clinical laboratory. Lymphocyte content of sodium, potassium, magnesium and calcium were measured simultaneously in a group of controls and found to fall within expected ranges. Expression of results per mg protein produced less inter-individual variation than per unit cell. In order to examine another, physiologically different but normal population, women during pregnancy were also studied. The cation content of lymphocytes expressed per mg protein was significantly lower than for controls due to a 44% increase in protein content per cell.

Hodgkin's disease of the skin. A case report.

A 74 year-old woman presented with cutaneous Hodgkin's disease and local bone involvement. Both were secondary to regional lymph flow obstruction by lymph nodes massively involved by nodular sclerosing Hodgkin's disease. Though a temporary remission was achieved by combination chemotherapy, skin lesions were quick to reappear in spite of continued treatment. This was felt to be due to local mechanical factors. A review of the literature reveals two main patterns of Hodgkin's disease of the skin. In one, the disease is either confined to the skin, or is unrelated to existing nodal or visceral involvement. In the other, skin infiltration is secondary to regional lymph node involvement by Hodgkin's disease, as seen in our patient. The pattern of skin involvement by Hodgkin's disease should be taken into consideration in assessing its prognostic significance.