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1.
Mammographic changes following reduction mammaplasty 总被引:2,自引:0,他引:2
Mammographic findings after reduction mammaplasty may be similar to those seen with carcinoma. A knowledge of the expected mammographic alterations would be helpful in differentiating postoperative changes from those seen with carcinoma of the breast. Accordingly, the clinical records and mammograms of patients who underwent reduction mammaplasty at the Dartmouth-Hitchcock Medical Center between March of 1977 and July of 1985 were analyzed. Forty-two patients had at least one mammographic examination following reduction mammaplasty. Periareolar soft-tissue changes and inferior pole alterations were present in almost all examinations of patients during the first 6 months after operation, but they decreased during the next few years. Asymmetrical densities were present in approximately half the patients throughout the follow-up period but decreased in degree. Parenchymal calcifications occurred later; few x-rays showed these calcifications during the first year, but 50 percent were apparent after 2 years. Evidence of fat necrosis occurred in approximately 10 percent. Four patients had biopsies for suspicious densities. Chronic inflammation and inclusion cyst were reported. We believe that changes after reduction mammaplasty are predictable and can usually be differentiated from those associated with cancer. 相似文献
2.
The increasing awareness of the medical profession and the general public of the dangers associated with ionizing radiation necessitates a thorough understanding by the physician of the uses and dangers of this hazard. In addition to their application in the fields of diagnosis and therapeutic radiology, x-rays and radioisotopes are increasingly used in research laboratories and in various industries. The effects of low levels of ionizing radiation are still uncertain and it is possible that there is a “threshold” dose at which cellular damage is evident. With the increased number of atmospheric nuclear tests the concentrations of strontium-90, cesium-137, and the shorter lived isotopes such as iodine-131 in food will increase. The present levels of these isotopes do not merit concern and their early efficient removal will assure continued low fallout levels in our major food supplies. 相似文献
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The malariologist Lewis Wendell Hackett famously observed that, "Like chess, (malaria) is played with a few pieces, but is capable of an infinite variety of situations". This paper discusses one such piece, the Red Queen. Red Queen phenomena arise when an intensification of effort leads to a need for further intensification to maintain the new status quo. Such phenomena represent dangers for current strategies to combat the disease. Understanding reproduction numbers is key to understanding these dangers. In this paper, we show why the variability and dynamics of reproduction numbers is important for analyzing the effects of interventions against malaria. This has importance for both formal modeling of malaria and for planning malaria intervention strategies in the field. 相似文献
5.
Jabes D 《Current opinion in microbiology》2011,14(5):564-569
There is an urgent need for new antibacterials to target emerging multidrug-resistant bacteria. The need for such agents is rising while the efforts in antibacterial research have declined dramatically in the past few decades with the result of only four compounds belonging to new chemical classes being approved for clinical use. The main reasons that led to this critical situation are shortly described. A renewed interest in the research of new effective antimicrobials is nonetheless delivering compounds deriving mainly from modification of existing drugs, yet new chemical classes are appearing. Because many of these activities have started relatively recently, we should expect a long period before new antibiotics are added to the medical armamentarium. 相似文献
6.
Functional disorders of the upper gastrointestinal tract frequently require the placement of biopsy tubes into the duodenum. At present, monitoring of correct placement of these tubes usually entails the use of x-rays involving a single or repeated exposures. For accurate placement of duodenal tubes, the difference in TPD between the stomach and the duodenum has been employed as a criterion. Measurement of the TPD is technically simple, can be done at the bedside and obviates the need for using x-rays. Suitable hardware and the procedure are described in detail. 相似文献
7.
J. R. Augustine 《CMAJ》1967,96(20):1367-1370
Laboratory studies on 109 acutely intoxicated male and female alcoholics admitted to the general medical wards of a community general hospital were undertaken. Initially the program was designed to study the thyroid function of these patients, as a previous report had noted that large numbers of alcoholics were thyroid-deficient. During the study, however, other laboratory examinations, which might be confusing or misleading in alcoholics, were also measured. These additional estimations included the serum glutamic oxaloacetic transaminase (SGOT), the serum cholesterol and the serum amylase. No patients were found to be hypothyroid. The results of the tests indicate the need for caution in interpreting SGOT and serum amylase results in acute alcoholics. 相似文献
8.
Palatal distraction in a canine cleft palate model 总被引:13,自引:0,他引:13
The purpose of this study was to determine whether the canine hard palate can be lengthened by distraction osteogenesis in a cleft palate model using a mostly submucosal distractor. Five mongrel dogs were used. After raising mucoperiosteal flaps, a midline strip of bone was removed from the hard palate of each dog to simulate the bony defect seen in a cleft palate. A transverse osteotomy was then made to separate the posterior segment of the hard palate from the anterior segment. Posterior osteotomies were also made laterally parallel to the teeth so that the 2 posterior segments (one on either side of the bony cleft) were mobile. An intraoral distractor that was mostly submucosal was attached to the anterior hard palate and both segments of the mobilized posterior hard palate. Radiopaque bone markers were placed, and x-rays were obtained. After a 10-day latency period, the distractor was expanded 0.675 mm per day until it had been lengthened 10.125 mm. Distractors were left in place for an additional 8 weeks. After distractor removal, animals were observed for an additional 8 weeks before euthanization. Follow-up x-rays and histologic examinations were performed. New bone formation was found at the site of distraction in all dogs at the time of death. This new bone was seen on the follow-up x-rays and on histologic examination of the hard palates using both hematoxylin and eosin staining and Masson's trichrome stain. Distraction osteogenesis using a mostly submucosal device is an effective technique for lengthening the hard palate in a canine cleft palate model. The technique may eventually provide an alternative treatment for velopharyngeal incompetence in humans that is more precise and involves less morbidity than existing treatments. 相似文献
9.
The use of structured clinical examinations to improve the evaluation of medical students and graduates has become significantly more common in the past 25 years. Many Canadian medical educators have contributed to the development of this technique. The Canadian experience is reviewed from the introduction of simulated-standardized patients and objective-structured clinical examinations to more recent developments and the use of such examinations for licensure and certification. 相似文献
10.
The need for alternative ways to control helminth parasites has in recent years led to a boost in vaccination experiments with recombinant antigens. Despite the use of different expression systems, only a few recombinants induced high levels of protection against helminths. This is often attributed to the limitations of the current expression systems. Therefore, the need for new systems that can modify and glycosylate the expressed antigens has been advocated. However, analysis of over 100 published vaccine trials with recombinant helminth antigens indicates that it is often not known whether the native parasite antigen itself can induce protection or, if it does, which epitopes are important. This information is vital for a well-thought-out strategy for recombinant production. So, in addition to testing more expression systems, it should be considered that prior evaluation and characterization of the native antigens might help the development of recombinant vaccines against helminths in the long term. 相似文献
11.
Until recently, osteotomies and surgeries to reposition prominent zygoma have been performed by means of a coronal incision or intraoral and preauricular incisions. Such incisions have penalties such as scars, the possibility of facial nerve injury, and long operative times. After reflecting on their past experiences with facial bone surgery, the authors developed an alternative approach. In this method, the cheekbone protrusion is corrected by performing an osteotomy and repositioning through an intraoral incision only. During the past 3 years, the authors have operated on 23 patients with malar prominences. The amount of bone to be removed is determined by preoperative interviews, physical examinations, and x-rays. Intraoral incisions provide access to the zygomatic body and lateral orbital rim. After L-shaped osteotomies (two parallel vertical and one transverse osteotomy at the medial part of the zygomatic body), the midsegment is removed. The posterior portion of the zygomatic arch was approached through the medial aspect and was outfractured using a curved osteotome. After completing the triple osteotomy, the movable zygomatic complex was reduced medially and fixed with miniplates and screws on the zygomaticomaxillary buttress. The patients were followed for 9.5 months, with acceptable results and few complications. The authors conclude that this technique is an effective and safe method of reduction malarplasty. 相似文献
12.
The use of information technology in improving medical performance. Part II. Physician-support tools
Increasing data from a few sites demonstrate that information technologies can improve physician decision making and clinical effectiveness. For example, computer-based physician order entry systems, automated laboratory alert systems, and artificial neural networks have demonstrated significant reductions in medical errors. In addition, Internet services to disseminate new knowledge and safety alerts to physicians more rationally and effectively are rapidly developing, and telemedicine to improve rural access to specialty services is undergoing substantial growth. However, even technologies demonstrated to yield beneficial effects have not yet achieved widespread adoption, though the pace of change appears to be increasing as the Internet takes hold. Scientific evaluation of many technologies is also lacking, and the dangers of some of these technologies may be underappreciated. Research on the effects of specific technologies should be a priority. Policies should be developed to press information technology companies, such as pharmaceutical and medical device manufacturers, to recognize the importance of clinical evaluation. Research could also analyze the characteristics of effective technologies and of physicians and organizations who implement these technologies effectively. 相似文献
13.
The discovery of x-rays was announced by German physicist Wilhelm Conrad Röntgen in December 1895. This review of the introduction of the use of x-rays in Kingston, Ont., shows the rapidity of their adoption in Canadian medicine. By February 1896 "x-ray photographs" were being taken by Captain John Cochrane of the Royal Military College of Canada in Kingston. Initially a scientific and popular curiosity, the new rays were quickly applied to medicine, and by the fall of 1896 the Kingston General Hospital had acquired its own x-ray apparatus. The hospital superintendent, Dr. James Third, became a leading practitioner and promoter of radiographic diagnosis and radiation therapy. He published, in 1902, the first comprehensive review of the diagnostic and therapeutic uses of x-rays by a Canadian physician. Third''s writings reveal his technical knowledge, his organized approach to the application of radiography to clinical medicine and his cautious attitude. Like other physicians who have witnessed the introduction of new diagnostic techniques, Third feared that the new technology would usurp the physician''s clinical skills. 相似文献
14.
The unique development of early medical specialization in the West can be traced to California''s geography and economic development. Such early specialization produced men with orthopedic inclinations. Early orthopedists founded the first medical school and the first modern teaching hospital, helped to found Stanford''s Lane Medical Library and made the first use of x-rays in the West. In addition many of these orthopedists were prominent in the political and social activities of the time. 相似文献
15.
Mortell N 《Lab animal》2007,36(8):46
Having done the hard work in winning your new job, you might find fitting into a new environment to be just as demanding. Don't make the common mistake of focusing solely on work and getting results. You need to pay equal attention to nurturing good relationships with your new colleagues. Here are a few more hints to help ensure that you get off to the best possible start. 相似文献
16.
Frederik Flindt Kreiner Bernt Johan von Scholten Peter Kurtzhals Stephen Charles Langford Gough 《Aging cell》2023,22(5):e13818
To help ensure an expanded healthy lifespan for as many people as possible worldwide, there is a need to prevent or manage a number of prevalent chronic diseases directly and indirectly closely related to aging, including diabetes and obesity. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have proven beneficial in type 2 diabetes, are amongst the few medicines approved for weight management, and are also licensed for focused cardiovascular risk reduction. In addition, strong evidence suggests several other beneficial effects of the pleiotropic peptide hormone, including anti-inflammation. Consequently, GLP-1 RAs are now in advanced clinical development for the treatment of chronic kidney disease, broader cardiovascular risk reduction, metabolic liver disease and Alzheimer's disease. In sum, GLP-1 RAs are positioned as one of the pharmacotherapeutic options that can contribute to addressing the high unmet medical need characterising several prevalent aging-related diseases, potentially helping more people enjoy a prolonged healthy lifespan. 相似文献
17.
Leslie E. Blumenson 《Mathematical biosciences》1976,30(3-4)
Periodic screening programs for the early detection of chronic diseases such as cancer and heart disease may not always lead to a reduction in the number of deaths from the disease. Some improvement is usually possible with the use of a more sensitive detection test, or by lowering the age for the first screening examination, or by decreasing the period between examinations. However, the extent of the reduction in deaths that is attainable with these changes is limited by the underlying biological behavior of the disease as well as by the rate at which the disease is detected without the screening examination, i.e., by the “natural history” of the disease. The effectiveness of a periodic screening program is derived as a function of this natural history, the period between examinations, the sensitivity of the detection test, the age at the first examination, and the age distribution of the rate of the disease initiation in the screened population. A detailed discussion is given of how these results might be used to estimate the effectiveness of any planned periodic screening program. The analysis of a simple example suggests that for some diseases decreasing the interval between screening examinations may not lead to a significant lowering of the death rate, i.e., there may be a natural lower bound on the screening period. 相似文献
18.
Joseph Sternberg 《CMAJ》1973,109(1):51-57
Irradiation during pregnancy may occur either as the result of radioactive pollution of the environment, or during a medical procedure using x-rays or radionuclides. While the former is usually unforeseeable, the latter is known and accepted by both physician and patient.Recent statistics estimate that about one quarter of pregnant women have had a radiographic experience during the pregnancy, either for obstetrical reasons or in the course of medical and dental examinations. The amount of radiation delivered to the fetus is in the range of one rad or less. Radionuclidic procedures may result in fetal radiocontamination, chiefly after placental transfer and fetal uptake. Radioiodine, radioactive calcium and selenomethionine are dangerous for the fetus, since they cross the placenta freely and are taken up by fetal tissues. The labelled proteins, radiocolloids and some mercury compounds remain in the maternal compartment and therefore can affect the fetus only through their gamma radiation at some distance from the fetus.The teratogenic effect, the leukemogenic threshold and the lowered resistance to neonatal infections have been demonstrated after irradiation with doses far higher than those encountered during diagnostic applications of ionizing radiation. Statistical data suggest an increase of susceptibility to leukemia in infancy after intra-uterine irradiation at a diagnostic level. Cytogenic analysis may.... offer valuable data for the establishment of the extent of radiation damage. 相似文献
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Daniel D. Reidpath David Crawford Linda Tilgner Carl Gibbons 《Obesity (Silver Spring, Md.)》2002,10(6):526-531
Objective: To examine the relationship between body mass index (BMI) and the use of medical and preventive health services. Research Methods and Procedures: This study involved secondary analysis of weighted data from the Australian 1995 National Health Survey. The study was a population survey designed to obtain national benchmark information about a range of health‐related issues. Data were available from 17,033 men and 17,174 women, ≥20 years or age. BMI, based on self‐reported weight and height, was analyzed in relation to the use of medical services and preventive health services. Results: A positive relationship was found between BMI and medical service use, such as medication use, visits to hospital accident and emergency departments (for women only); doctor visits, visits to a hospital outpatient clinics; and visits to other health professionals (for women only). A negative relationship was found in women between BMI and preventive health services. Underweight women were found to be significantly less likely to have Papanicolaou smear tests, breast examinations, and mammograms. Discussion: This research shows that people who fall outside the healthy weight range are more likely to use a range of medical services. Given that the BMI of industrialized populations appears to be increasing, this has important ramifications for health service planning and reinforces the need for obesity prevention strategies at a population level. 相似文献