Heme synthesis in hereditary hemolytic anemias: decreased delta-aminolevulinic acid synthetase in hemoglobin K?ln disease

The activities of delta-aminolevulinic acid (ALA) synthetase and ALA dehydratase in cord blood erythrocytes of newborn infants and peripheral blood red cells of patients with beta-thalassemia major, beta-thalassemia intermedia, hemoglobin K?ln (Hb K?ln) disease, sickle cell anemia, and pyruvate kinase deficiency were studied. The activity of ALA dehydratase did not vary appreciably with the number of immature RBC (reticulocytes and nucleated red blood cells) or the severity of the hemolytic anemia except in pyruvate kinase deficiency. The activity of ALA synthetase was linearly correlated with the number of immature RBC (r=0.974, p is less than 0.001). The ALA synthetase activity was significantly decreased in the RBC of Hb K?ln (p is less than 0.01) when compared with the activity in immature RBC of newborns and of patients with pyruvate kinase deficiency, sickle cell anemia, and thalassemia intermedia.     

The Blalock-Taussig operation: the procedure of choice in the hypoxic infant with tetralogy of Fallot

An experimental model is presented enabling an analysis of the healing process of completely cut and re-sutured free segments of rabbit flexor tendons, kept avascular in a synovial milieu and completely isolated from adhesion formation. Under these conditions the cut tendons heal within a few weeks. It can be shown that this healing process is a result of intrinsic tendon cell activity only.     

Marginal neutrophil pool size in normal subjects and neutropenic patients as measured by epinephrine infusion

The marginal granulocyte pool (MGP) was measured by epinephrine infusion in normal and neutropenic subjects. Neutrophil response curves to doses of 0.025 to 0.3 mg. in three normal subjects indicated that maximal neutrophil response was achieved by 0.1 mg. In 21 normal subjects, absolute neutrophils increased from 700 to 3,100 per microliter. The percentage increase ranged from 18 to 107 per cent of baseline. The per cent increase tended to be greater with low-normal baseline neutrophils than with high-normal neutrophils, although this relationship was not observed when increase was determined in absolute values. In neutropenic patients mean per cent increase of neutrophils was greater than observed in normal subjects, 121 vs. 50 per cent. Although the increase expressed in absolute neutrophil numbers was less in subjects with lower baseline neutrophil concentrations, there was an inverse correlation between the baseline neutrophil concentrations, there was an inverse correlation between the baseline neutrophils and the per cent increment following epinephrine. Mean increase was 200 per cent in patients with less than 200 neutrophils per microliter, compared with 61 per cent in patients with 1,000 to 1,500 neutrophils per microliter. These results indicate that circulating granulocyte pool (CGP) size may be misleading with respect to total blood neutrophils and in a sense confirm the concept of shift neutropenia, a decreased CGP and MGP as neutropenia becomes more profound suggests that shift neutropenia may be a normal physiologic methanism rather than a distinct neutropenic syndrome.     

Comparison of the temperature sensitivity of protein synthesis by cell-free systems from liver of rat and skate (Raja ocellata)

Studies were undertaken to determine the component(s) responsible for the temperature optimum characteristic of the protein-synthesizing system from skate and rat. 1. The macromolecular constituents of rat and skate liver ribosomes are compared. The number of ribosomal proteins is similar in the two species, although most proteins display different electrophoretic mobilities on polyacrylamide gels. The RNAs from the small subunit of skate and rat have similar sedimentation coefficients; however, the RNA from the large subunit of skate ribosomes appeared to be slight smaller than the comparable RNA from the rat. 2. Ribosomes from either rat or skate were capable of supporting poly(U)dependent polyphenylalanine synthesis with soluble factors from either species. 3. Maximal leucine incorporation directed by endogenous mRNA occurred at 35--40 degrees C with post-mitochondrial supernatant from the rat liver and at 20--30 degrees C with that from skate liver. 4. The characteristic temperature sensitivity of protein synthesis was dependent upon the source of cell sap and independent of the source of ribosomes. 5. Elongation factor 1 from both the rat and skate exhibited maximum activity at approx. 30 degrees C. 6. Phenylalanyl-tRNA synthetase from skate liver showed maximum activity at 30 degrees C while that from rat was maximally active at 37 degrees C. The rat enzyme, however, was active at 0--10 degrees C, at which temperature protein synthesis in the reconstructed rat system is virtually absent. 7. The protein-synthesizing capacity of the reconstituted system at various temperatures was closely correlated with the activity of Elongation factor 2 (translocase). Elongation factor 2 from rat liver displayed an optimum at 30 degrees C and lost all activity below 10 degrees C, while this same factor from skate liver showed an optimum at 20 degrees C and significant activity below 10 degrees C. At this low temperature the reconstituted skate liver system continued to exhibit the ability to synthesize protein. These studies suggest that Elongation factor 2 is the component responsible for determining the temperature at which the protein-synthesizing system displays its characteristic maximum activity.     

Gastric emptying of solid meals in diabetics

The gastric emptying rate of an isotopically labelled solid meal was compared in 29 insulin-dependent well-controlled diabetics and 18 normal controls. The diabetics were assessed for evidence of autonomic neuropathy. No significant difference in gastric emptying rate was found between controls and diabetics with or without autonomic neuropathy. Only three diabetics had greatly delayed gastric emptying, but in one of these the test had given a normal result on an earlier occasion.     

Forearm fractures in children: pitfalls and complications

Five hundred fourty-seven consecutive forearm fractures in children were studied, with special emphasis on complications encountered. The most important apparent conclusion reached from this study is that greenstick and complete fractures are different, and that some of the pitfalls and complications seen following these injuries can be avoided if different methods of reduction are used for each. Greenstick fractures should be reduced by manipulating them into the correct proper plane of rotation; i.e., maximum pronation for distal third fractures, neutral for middle third fractures, and supination for proximal third fractures. Application of this familiar "rule of thirds" to complete fractures, however, may result in ratational deformity at the fracture site. Completer fractures should be reduced by finger trap traction, allowing the fracture to seek its own level of rotation. Several other observations were also noted. Angulation into radial deviation was found to remodel and equally as well as volar angulation, and remodeling may contine for as long as two years after injury. Growth disturbance following fractures through the distal radial epiphyseal plate is uncommon, but premature closure of the epiphysis did occur in one patient with a typical Type II fracture. Six concomitant nerve injuries were seen; all recovered spontaneously within 3 weeks.     

The genetics of glutamate oxaloacetate transaminase in Drosophila melanogaster

A survey of 29 laboratory populations of Drosophila melanogaster for glutamate oxaloacetate transaminase (GOT) variation revealed that the Got-1 locus was polymorphic in three stocks recently collected from nature. The Got-1 locus was fixed for the same allozyme in the remaining 26 laboratory populations. Testcross matings to multiply marked stocks established that Got-1 is located at 4.8 centimorgans on chromosome 2.     

1. The chemistry and biology of flooded soils in relation to the nitrogen economy in rice fields

Response of lowland rice to sources and methods of nitrogen fertilizer application were summarized for more than 100 experiments. In about 2/3 of the experiments, the yield increase per kg of fertilizer N was judged to be relatively poor with best split applications of urea. Based on frequency distribution, sulfur coated urea and urea briquets or urea supergranules deep placed more often produced satisfactory yield increases than best split urea, but even with these sources/methods the yield increases were judged to be relatively poor in about 1/2 of the experiments. There is an enormous potential to increase rice production with no further increases in inputs of fertilizer N if we could learn to match the best method/source of fertilizer with the soil-crop management complex.About 60% of the yields with no fertilizer N were in the range of 2 to 4 t/ha. Based on the average yield response to urea, this is equivalent to about 100 kg of urea N. It would appear worthwhile to study ways to improve utilization of soil nitrogen since it is already in place on the land and apparently in fairly abundant amounts in many soils.About 50 experiments with¹⁵N fertilizers were summarized. In almost all cases, the uptake of tagged fertilizer was less than the net increase in N in the above ground matter. In about 2/3 of the experiments, the addition of fertilizer N increased soil N uptake more than 20% and in 1/3 of the experiments the uptake of soil N was increased more than 40%. These results lead to much uncertainty about practical interpretation and use of¹⁵N data.