Mechanical strength of acrylic bone cements impregnated with antibiotics

Admixing of several antibiotic powders which were insoluble in methyl methacrylate did not decrease the compressive and diametral tensile strengths of two acrylic bone cements when tested after setting for 1 day and after leaching 40 days in water at 37 degrees C. When antibiotics were added as water solutions, the included water resulted in a significant decrease in these bulk mechanical properties. Storage in water for 40 days caused surface irregularities only on specimens of the set antibiotic admixtures. Approximately 0.5% of the admixed dosage of these water-soluble antibiotics could be leached from the set cements. The observed surface channels, presumably left by the loss of antibiotic, suggest further study of surface-sensitive mechanical properties may be needed. The bulk mechanical strengths presented here are conclusive only for the particular combinations of antibiotics and cements investigated, and should not be generalized at this time to any or all antibiotic admixtures or other mechanical properties.     

Sudden infant death syndrome. A prospective study

One hundred twenty-five sudden infant death syndrome (SIDS) victims followed up since birth from a large prospective study were compared with matched controls. Some of the future SIDS victims showed evidences of neonatal brain dysfunction including abnormalities in respiration, feeding, temperature regulation, and specific neurologic tests. These abnormalities could not be ralated to events in labor or delivery. A greater proportion of the future victims were mildly underweight for gestational age. The gestations that produced the SIDS victims were characterized by a greater frequency of mothers who smoked cigarettes and had anemia. The demographic profile of SIDS families proved to be indentical to the profile for families with excessive perinatal mortality. Many of the SIDS victims showed a retardation in postnatal growth prior to death.     

Hemangioma of bladder

A twenty-nine-year-old woman had a history of recurring gross, total painless hematuria. The past history and urologic studies supported the diagnosis of hemangioma of the bladder. A partial cystectomy was performed. The pertinent literature is reviewed.     

Sebaceous gland inhibition from combined glucocorticoid-estrogen treatment

Sebum production in seven hirsute women was found to be markedly inhibited by low-dosage glucocorticoid therapy, usually 5 to 10 mg of prednisone daily, combined with the cyclic administration of ethinyl estradiol, either 80mug or 100mug daily, in the form of oral contraceptive medication. The average reduction of sebum secretion was 85.7%, from a pretreatment mean value of 3.07 mg of sebum to an average treatment level of 0.44 mg.     

Improvement of perfusion-flow in the isolated rat liver, under the influence of streptase

Accumulation of radioactive material in the isolated rat liver was noted when 125I-fibrinogen was added to the perfusing medium. Owing to an enhanced production of fibrinogen and to a diminished fibrinolysis, fibrin deposits were found to occur in the capillaries of fhe isolated liver. This would cause a decrease of hepatic flow and an impairment of the nutrition of this organ which leads to subsequent necrosis. Administration of streptase removed the fibrin deposits and restored the perfusive flow in the isolated liver.     

Juvenile gastrointestinal polyposis

Two cases of juvenile gastrointestinal polyposis are described and the literature is reviewed. Despite the benign nature of the individual polyps, the disease has a poor prognosis. Of 13 reported patients, 4 had macrocephaly, and one of the authors' 2 patients had large peripheral intracranial cysts. This appears to be the first reported documentation of the etiology of macrocephaly associated with juvenile polyposis. Major clinical problems are related to severe loss of blood and protein from the gastrointestinal tract.     

Left ventricular function by echocardiography in children with fixed aortic stenosis

Left ventricular function was evaluated echocardiographically within 24 hours of cardiac catheterization in 45 children with fixed aortic stenosis. Left ventricular systolic time intervals, mean velocity of circumferential fiber shortening, left ventricular end-diastolic volume and shortening fraction were evaluated. Some patients with severe aortic stenosis had a shortened preejection period, prolonged ejection time and increased mean velocity of circumferential fiber shortening in comparison with normal subjects, but these findings were not consistent within the group with severe aortic stenosis or apparent in patients with mild or moderate aortic stenosis. Left ventricular end-diastolic volume was smaller in children with severe obstruction than in normal children. Evaluation of the shortening fraction provided good separation of patients with significant obstruction from those with mild disease. Further, there was a linear correlation between the shortening fraction and the left ventricular-aortic gradient demonstrated at cardiac catheterization. This correlation was also of use in evaluating the response of patients to surgical relief of obstruction. Pre- and postoperative echocardiographic evaluation of the shortening fraction appears to provide a readily available noninvasive method of assessing the course and severity of obstruction in fixed aortic stenosis in children.     

Regulation of nitrogen catabolic enzymes in chick liver -- effects of amino acids

It is well-known that in the chick, dietary protein increases the levels of several hepatic enzymes that are involved in nitrogen metabolism and excretion. However, the biochemical mechanism of this response is essentially unknown. The experiments presented in this paper show that the chick is responding to alpha-amino nitrogen and not to any specific amino acid. Furthermore, it is shown that this system responds to endogenous sources of nitrogen as well as dietary protein and that the xanthine dehydrogenase response involves regulation of enzyme synthesis without changing the rate of degradation.     

Partial replacement of chicken semen by turkey semen in artificial insemination of chickens

Chicken semen undiluted, diluted with a diluent containing fructose and/or mixed with turkey semen was used to inseminate Leghorn hens. In two of three experiments there was an improvement in fertility from insemination by mixed semen as compared to semen diluted to the same extent with the diluent.