Prognostic significance of an ST segment depression of patients with an acute coronary attack

An ST-segment depression was studied in the ECGs recorded on the first and third day after admission of 580 patients with an acute heart attack. An acute myocardial infarction was found in 86% of the 115 patients in whose ECG the J-point was depressed 2 mm. or more and the ST-segment was horizontal or sloping downwards in at least one lead (a definite ST-segment depression).The degree of the J-point depression was deemed of prognostic significance. During the first four weeks, the mortality rate was lowest (4.7%) in patients with a J-point depression less than one millimeter or no depression. The corresponding figure for patients with a definite ST-segment depression was three times (21.7%) that of the patients without the pattern (7.3%).The definite ST-segment depression in an acute coronary attack seemed to be accompanied by a severe degree of coronary heart disease. Significant differences between the patients with a definite ST-segment depression and those without the pattern were found in the $\text{C}\text{T}$ ratio, in the degree of pulmonary congestion, in the ECG signs of LVH, and in the digitalis treatment.It is concluded that the definite ST-segment depression has an important clinical and prognostic significance in cases of acute coronary attacks.     

Changes in the QRS complex and ST segment in transmural and subendocardial myocardial infarctions. A clinicopathologic study.

The QRS complex and ST segment in the ECGs of 80 patients who died of an acute myocardial infarction (MI) were studied in relation to the extent of the MI (subendocardial vs. transmural). Changes in the QRS complex developed in nine out of the 15 cases with an acute subendocardial MI. Five of these cases fulfilled the conventional QRS criteria for a myocardial infarction. A definite ST segment depression (a J point depression of 2 mm. or more in at least one lead, and a horizontal or downward sloping ST segment with a minimum duration of 0.08 sec.) occurred most frequently in connection with a circumferential subendocardial MI (88 per cent), but it was also found in a regional subendocardial (43 per cent) and transmural MI (43 per cent). In 17 per cent of the cases with a transmural MI, this was the only ECG abnormality. It is concluded that cases with a subendocardial MI cannot always be distinguished from transmural MI on the basis of the presence or absence of the QRS changes, and that an ST segment depression, as defined in this study, can give additional information in the evaluation of an acute phase of an MI.     

How are individual-level social capital and poverty associated with health equity? A study from two Chinese cities

Background  

A growing body of literature has demonstrated that higher social capital is associated with improved health conditions. However, some research indicated that the association between social capital and health was substantially attenuated after adjustment for material deprivation. Studies exploring the association between poverty, social capital and health still have some serious limitations. In China, health equity studies focusing on urban poor are scarce. The purpose of this study is therefore to examine how poverty and individual-level social capital in urban China are associated with health equity.     

The stability of femoral neck fractures and its influence on healing

We measured the stability of fixation in femoral neck fractures treated with von Bahr screws, investigated the influence of impaction and correlated peroperative stability with the clinical results. Stability was measured at operation using a metal probe fitted with strain gauges. Its tip was anchored in the subchondral bone of the femoral head and its lateral end was fixed in the lateral femoral cortex. The shearing force produced by longitudinal compression applied to the foot of the operated leg was recorded. The results in 41 consecutive patients all followed for 30 months, showed that fractures with early loosening or nonunion had all had significantly poorer stability than the fractures that had healed. Impaction improved stability in only 23 out of the 41 fractures; in the others stability had deteriorated or was unchanged.     

Toxicity of mercuric chloride to the developing rat kidney. III. Distribution and elimination of mercury during postnatal maturation

Mercuric chloride is a potent nephrotoxicant in the adult rat, but has little effect on newborns. Nephrotoxicity increases with postnatal maturation. This study assesses the changes in tissue distribution and excretion of Hg during postnatal development. Sprague-Dawley rats were injected sc with 5 mg/kg 203HgCl2 on postnatal Day 1, 8, 15, 22, or 29. Hg concentration was measured in the whole body, renal cortex, medulla and papilla, liver, and subcellular fractions of liver and kidney. Binding to cytosolic metallothionein was assessed. Whole-body elimination of Hg was slow at the three younger age groups, as only 20% of the initial load was eliminated by 5 days after injection. Excretion was much more rapid in the two older groups, which eliminated about half of the initial load within 5 days. Concentration of Hg was highest in renal cortex (the principal site of Hg toxicity), and there was an age-related increase in cortical Hg concentration. This may explain the increased toxicity of Hg with age. There was an age-related decrease in hepatic Hg concentration. The high levels of metallothionein present in perinatal rat liver may protect the renal cortex from receiving a toxic dose of Hg; however, the increased concentration of hepatic Hg in newborns is insufficient to account for all of the cortical decrease. It is probable that Hg was distributed to other tissues. In liver and kidney cells of neonates, Hg concentration was highest in the cytosol, decreasing in an age-related manner. This was accompanied by an age-related increase of Hg in the nuclear/mitochondrial fraction. Hg in the cytosol was largely bound to metallothionein, although there were substantial amounts associated with very low-molecular-weight molecules and high-molecular-weight proteins. There are significant maturational changes in the organ, cellular and subcellular distribution of Hg in the rat during the first 4 weeks after birth. These probably explain the increasing sensitivity with maturity to Hg nephrotoxicity.     

Subchondral screw fixation of cervical hip fractures: joint congruence studied with combined arthrography and tomography

This study was done to determine whether fixation with the Uppsala internal fixation technique into the subchondral bone of the femoral head in the treatment of cervical hip fractures could lead to elevation of the femoral head cartilage. Combined arthrography and frontal tomography of the hip joint in the plane of the screws was performed. The series consisted of 16 patients. In two of the patients, the tips of the screws had penetrated into the cartilage of the femoral head. In the other 14, the internal fixation was technically correct with the tips of the screws in the subchondral bone. In the two hips with the screws penetrating into the cartilage, the cartilage was slightly elevated. In the hips where the screws were in the correct position, no incongruities or deformity in the cartilage could be detected. Combined arthrography and frontal tomography can, therefore, detect elevation of the cartilage of the femoral head. By placing the screws in the immediate subchondral bone, no elevation of the cartilage of the femoral head surface should occur.