Radiographic studies on maturation process of secondary ossification centers in long bones of the Japanese white rabbit

The maturation process of the secondary ossification centers of the extremities was radiographically investigated in the Japanese white rabbit of both sexes aged 1 day to 78 weeks. The ossification centers appeared at 1 day of age in the proximal and distal epiphyses of humerus, the head of femur, the distal epiphysis of femur and the proximal epiphysis of tibia, at 1 week of age in the supraglenoid tubercle of scapula, the proximal and distal epiphyses of radius, the proximal and distal epiphyses of ulna, the greater trochanter of femur, the distal epiphysis of tibia and the distal epiphysis of fibula, and at 2 weeks of age in the proximal epiphysis of fibula. The ossification centers developed rapidly from the time of appearance to 8 weeks of age, and gradually thereafter until 32 weeks of age. By 78 weeks of age, the complete fusion with the diaphysis was observed in the supraglenoid tubercle of scapula, the proximal and distal epiphyses of humerus, the head and distal epiphysis of femur. Incomplete fusion, leaving an epiphyseal line, was found in the proximal and distal epiphyses of radius, ulna, tibia and fibula, respectively.

Pulmonary complications of long-term respirator care in infants

Twelve infantile autopsy cases up to 205 days using a long-term respirator care were examined in this study. These cases could be divided into three subgroups. The first group included the cases treated with long-term respirator care for hyaline membrane disease. In this subgroup, bronchopulmonary dysplasia was found during the course. The second group included the cases treated with long-term respirator care for other causes and were very premature infants. In this group, some cases showed bronchopulmonary dysplasia-like lesions. The third group was similar to the second group except for not being very premature. All groups had similar histological changes including alveolar cell desquamation, regeneration of alveolar lining cells, fibrosis, and smooth muscle-like tissue formation of alveolar walls. However, the premature lung tissues remained characteristically in some cases of the second group. In this group, the prematurity of lung was thought responsible for the development of bronchopulmonary dysplasia-like lesion. In addition to bronchopulmonary dysplasia or bronchopulmonary dysplasia-like lesion, other changes including pneumonia, persistent ductus arteriosus, cytomegalic inclusion disease and so forth were discussed.

Left ventricular performance and compliance following acute febrile mucocutaneous lymphnode syndrome

Right and left heart catheterizations and biplane cineangiographies were performed on 115 post-MCLS cases to study the left ventricular performance and compliance, and the following conclusions were obtained: 1) The left ventricular performance of the post-MCLS cases with macroscopic cardiac lesions such as coronary aneurysms and stenosis declined compared with the others. 2) The left ventricular contractility of the post-MCLS cases without macroscopic cardiac lesions were within normal limits. 3) The diastolic compliance of the post-MCLS cases seemed to be decreased but the value could be regarded as normal for children.

Modifications by lidocaine and its N-dealkylated metabolites of the response of the isolated rabbit aorta to transmural electrical stimulation

Contractile responses of rabbit aortic strips to transmural stimulation and to exogenously applied norepinephrine (NE), potassium chloride (KCl), and histamine were studied in the presence of lidocaine or its metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX). Lidocaine, 10(-4) and 5 x 10(-4) M, attenuated the contractile response to transmural stimulation, whereas MEGX, 2 x 10(-5) and 10(-4) M, potentiated, but 10(-4) M, potentiated the response to transmural stimulation. The suppression induced by lidocaine and MEGX was not reversed by excess calcium, 2.2 and 4.4 mM, but was partially reversed by cocaine, 3 x 10(-6) M. Lidoncaine, 5 x 10(-4) M, and MEGX, 2 x 10(-3) M, shifted the dose-response curve of NE to the right, whereas GX, 5 x 10(-4) M, shifted the curve to the left. The maximum tension developed by K+ was attenuated by lidocaine, 5 x 10(-4) M, MEGX, 5 x 10(-4) and 2 x 10(-3) M, and GX, 2 x 10(-3) M. It may be concluded that lidocaine attenuates the response to stimulation of sympathetic nerves innervating the arterial wall by interfering with the release of NE. In contrast, the metabolites, MEGX and GX, potentiate the response, possibly by increasing the release of NE. MEGX in high concentrations appears to have the same mechanism of inhibitory action as does lidocaine.

Effects of amino acid infusion and renal failure on the uptake and release of amino acids by the dog kidney

Net production and utilization (Qmet) of amino acids and ammonia were assessed in the left kidney of 11 normal and eight chronically uremic female dogs. Studies were conducted at the end of two 120-min infusions, first with half-normal saline and then with amino acids which increased plasma concentrations to postprandial levels. In the normal dogs, Qmet for a number of amino acids and ammonia was significantly positive (i.e., net production) or negative (i.e., net utilization). Qmet became more negative with the amino acid infusion. In the uremic dogs, Qmet for amino acids and ammonia was qualitatively similar to normal and tended to change in the same direction with the amino acid infusion. Although the absolute values for Qmet were usually less in the uremic dogs, with the amino acid infusion their mean fractional Qmet (Qmet/creatinine clearance) was often greater. A substantial proportion of the infused amino acids was removed by the kidney) in both groups of dogs. In the uremic dogs, there was evidence for preservation of glomerular-tubular balance between the filtered load of amino acids and tubular reabsorption. Data also suggest that the kidney may release sufficient quantities of certain amino acids into renal venous blood (e.g., serine) to affect the plasma levels. These findings indicate that the dog kidney may make an important contribution to total synthesis or metabolism of certain amino acids by the body and may also affect plasma concentrations of some amino acids. During amino acid infusion, the kidney plays a major role in removal of the added amino acids. In renal failure these functions are decreased, but compared to the fall in glomerular filtration rate, they are relatively well preerved.

Comparative studies on maturation process of secondary ossification centers of long bones in the mouse, rat, dog and monkey

Comparative studies was made on the whole processes of maturation of the secondary ossification centers in the extremity in the mouse, rat, dog and monkey in order to determine points of similarity and difference among these species. The appearance and the union of the secondary ossification centers were observed to follow a common sequence and order in all the species examined. The total bone score was defined as the sum of the bone scores of respective secondary ossification centers over the observation period according to a set criteria. By plotting these indices against the chronological age it was shown in all of these species that the whole process of maturation of the secondary ossification centers in the long bone consisted of three biological stages as indicated by the three straight lines with different slopes. The first stage is considered to account for the appearance of the secondary ossification centers and their accelerated development at early period, while the second stage corresponds to the subsequent gradual development. The third stage represents a period where the ossification centers reach a complete or almost complete unmion to diaphysis. It is concluded that in the mouse, rat, dog and monkey the maturation process of the secondary ossification centers follow the same growth consisting of three developmental stages and that each of these three stages provides a measure of comparison among these species.