By U. Vigo. Polytechnic University of Puerto Rico.
In 1956 Berg demonstrated (DNA)—the substance that carries genetic information in liv- just such a molecule discount panmycin 250mg otc, which was specific to the amino acid ing cells from generation to generation—from different types methionine buy discount panmycin 500mg on-line. Berg’s achievement, one of the most fundamen- are now called transfer RNA (tRNA). It also allowed researchers to turn study how these individual units of heredity worked. Berg rea- simple organisms into chemical factories that churn out valu- soned that by recombining a gene from one species with the able medical drugs. In 1980 Berg was awarded the Nobel genes of another, he would be able to isolate and study the Prize in chemistry for pioneering this procedure, now referred transferred gene in the absence of confounding interactions to as recombinant DNA technology. The commercial application of Berg’s work underlies a In the late 1960s, while at Stanford, Berg began study- large and growing industry dedicated to manufacturing drugs ing genes of the monkey tumor virus SV40 as a model for and other chemicals. Moreover, the ability to recombine understanding how mammalian genes work. By the 1970s, he pieces of DNA and transfer them into cells is the basis of an had mapped out where on the DNA the various viral genes important new medical approach to treating diseases by a occurred, identified the specific sequences of nucleotides in technique called gene therapy. It was this work with SV40 sons of Harry Berg, a clothing manufacturer, and Sarah genes that led directly to the development of recombinant Brodsky, a homemaker. While studying how genes controlled the Abraham Lincoln High School, from which he graduated in production of specific proteins, Berg also was trying to under- 60 WORLD OF MICROBIOLOGY AND IMMUNOLOGY Berg, Paul stand how normal cells seemed spontaneously to become can- than continue his ground-breaking experiment, Berg voluntar- cerous. He hypothesized that cells turned cancerous because ily halted his work at this point, concerned that the tools of of some unknown interaction between genes and cellular bio- genetic engineering might be leading researchers to perform chemistry. In order to study these issues, Berg decided to combine In addition to this unusual voluntary deferral of his own the DNA of SV40, which was known to cause cancer in some research, Berg led a group of ten of his colleagues from around animals, into the common intestinal bacterium Escherichia the country in composing and signing a letter explaining their coli. He thought it might be possible to smuggle the SV40 collective concerns. Published in the July 26, 1974, issue of DNA into the bacterium by inserting it into the DNA of a type the journal Science, the letter became known as the “Berg let- of virus, called a bacteriophage, that naturally infects E. Two long chains of alternating sugar The Berg letter warned, “There is serious concern that and phosphate groups twist about each other, forming the sides some of these artificial recombinant DNA molecules could of the ladder. A base attaches to each sugar, and hydrogen prove biologically hazardous.
It is self-limited and usually runs a benign course over a period of weeks effective 500mg panmycin. It affects twenty-five thousand to fifty thousand children in the United States and accounts for 10–20 percent of all cases of juvenile arthri- tis order 250mg panmycin with mastercard. That one detail made a huge dif- ference in determining the correct diagnosis. Also, the classic tests for rheumatoid arthri- tis are usually negative, as Jessica’s were. Treatment of Still’s disease is directed toward the individual areas of inflammation. Many symptoms can be controlled with anti-inflammatory drugs, such as aspirin or other nonsteroidal drugs. Cortisone medications (steroids), such as prednisone, are used to treat more severe features of the illness. For those with persistent symptoms, medications that affect the 194 Diagnosing Your Mystery Malady inflammatory aspects of the immune system are used. Because of her mother’s diligence in working through the Eight Steps, Jessica didn’t have to suffer too long without the proper diagnosis or treatment. Case Study: David Eight-year-old David’s tooth problems probably had their origins in infancy. He would fall asleep with the bottle in his mouth at naptime and at night. David’s pediatrician surmised that the sugar in the milk lingered in David’s mouth and caused his teeth to decay.
Pinning results Number of joints: 71 JOA hip score: 100 points for all joints Complications (AVN cheap panmycin 500 mg mastercard, chondrolysis purchase panmycin 250 mg without prescription, etc. In all cases the Japanese Orthopaedic Association (JOA) hip score was 100 points of a pos- sible 100 points. Complications such as avascular necrosis (AVN) of the femoral head or chondrolysis were not observed. Leg length was examined in 24 cases that were pinned on both hips; 20 cases had no discrepancy and 4 cases had some leg length discrepancy less than or equal to 1cm. Imhaeuser’s osteotomy results Number of cases (joints): 22 (23) JOA score: >90 points Complication (AVN, chondrolysis, etc. The postoperative JOA hip score was more than 90 points of a possible 100 points. Early complications, including femoral head necrosis or chondrolysis, were not observed. The preoperative tilt angle of epiphysis, on average 52°, was reduced to less than 30° with an average of 22° after surgery. As for leg length, 20 cases had a discrepancy of less than 1cm, whereas the remain- ing 2 cases had a discrepancy less than 3cm. Except for 1 hip with an advanced stage of osteoarthritic (OA) change, 15 hips developed normally. Although 7 hips showed coxa valga, there was good joint congruity and no findings of OA change. Conclusion Long-term follow-up of SFCE, treated in accordance with Imhaeuser’s principle, showed satisfying results. Imhaeuser G (1962) Ueber Dislokation der proximalen Femurepiphyse durch Schae- digung der Wachstumzone (Dislokation der Hueftkopfepiphyse nach vorn-unten). Sofue M, Endo N (1993) Slipping of the femoral capital epiphysis (in Japanese).
