ACMC: past,present and future.

In this article, the president of the Association of Canadian Medical Colleges (ACMC) and its director of research review the issues that have confronted ACMC since its inception: the founding of ACMC; development of the clinical teaching unit; creation of the Medical Research Council and expansion of the research mission; the Royal Commission on Health Services and the founding of new faculties of medicine; ACMC''s in-house research program; accreditation and ACMC''s links with medical education in the United States; and French-language medical education in Canada. The review points out the perennial nature of many of these issues, and how often perceived solutions to the problems later become problems themselves. It ends on the optimistic note that ACMC can successfully meet the challenges of the future.     

Jehovah's Witnesses leading education drive as hospitals adjust to no blood requests.

Jehovah''s Witness representatives have visited more than 10 Canadian medical schools and 200 hospitals in an attempt to educate future and practising physicians about nonblood medicine. The trend is becoming more popular since the advent of HIV, and there are now about 100 bloodless medicine and surgery centres around the world, including 52 in the US. However, a Jehovah''s Witness spokesman says Canada is "conspicuously absent" from the list of countries that offer bloodless-medicine programs.     

A survey of postgraduate training for family practice.

The results of a survey of Canadian primary care physicians for the Canadian Medical Association (CMA''s) Task Force on Education for the Provision of Primary Care Services are reported. Recent Canadian medical school graduates in primary care practice reported that the three major training routes (rotating and mixed internships and family medicine residencies) each prepared them differently for practice. The graduates of 2-year family medicine residencies were more satisfied with their preparation than were the graduates of the other major training routes. A 2- or 3-year family medicine residency was preferred by 50% of the respondents, although only 33% of them had actually taken one of these routes. There was considerable agreement in the respondents'' assessments of the types of postgraduate education needed for primary care practice. The results of this survey were consistent with the recommendations in the final report of the CMA''s task force.     

An appreciation of A.E. Malloch,MB, MD (1844-1919): a forgotten surgical pioneer

Dr. Archibald Edward Malloch was a surgeon whose life and work were greatly influenced by Joseph Lister and his revolutionary system of antiseptic surgery. This paper describes how a young Canadian medical man came to introduce Lister''s system to North America in 1869 and studies his career in the light of Lister''s surgical epoch.     

Inhibiting calpain,rescuing cells.

Drs. John Elce and Peter Davies, biochemists at Queen''s University, Kingston, Ont., are investigating the molecular structure of calpain, an enzyme that has been implicated in the cellular damage that occurs after such events as myocardial infarction and stroke. This damage is precipitated by an imbalance in the regulation of calpain that arises as an indirect result of ischemia. Elce and Davies hope that their research, which involves techniques such as recombinant DNA technology and x-ray crystallography, will lead to the development of a calpain inhibitor that will prevent such damage from occurring and enhance recovery.     

帕金森病的临床治疗概况

帕金森病(Parkinson's disease, PD),在医学上称为"原发性震颤麻痹",又称"震颤麻痹",是一种中枢神经系统变性疾病,主要是因位于中脑部位"黑质"中的多巴胺(DA)能神经元病理性改变后,多巴胺的合成减少,对与其功能相互拮抗的乙酰胆碱的抑制功能降低,则乙酰胆碱的兴奋作用相对增强。两者失衡的结果便出现了"震颤麻痹"。本综述先从PD发病机制方向总结归纳目前临床常用的西医药物(包括左旋多巴、DA降解酶抑制剂、DA受体激动剂、抗胆碱能药物)、基因治疗靶点、手术治疗(脑深部电刺激术)及物理疗法,又从中医角度整体介绍了目前中医中药治疗以及针灸治疗等。因PD对患者的日常生活及身心健康造成了严重影响,我们希望通过本综述为PD综合治疗提供更广阔的临床思路及更好的方案。     

External beam radiation therapy with kilovoltage x-rays

Kilovoltage (kV) x-rays are most commonly used for diagnostic imaging due to their sensitivity to tissue composition. In radiation therapy (RT), due to their fast attenuation, kV x-rays are typically only used for superficial irradiation of skin cancer and for intra-operative RT (IORT). Recently, however, a number of kV RT techniques have emerged. In this review article, we provide a brief overview of the use of kV x-rays for RT.Various kV x-ray source technologies suitable for RT, such as conventional x-ray tubes as well as novel x-ray sources, are first described. This x-ray source section is then followed by a section on their implementation in terms of clinical, veterinary and preclinical applications. Specifically, IORT, superficial RT and dose enhancement with iodine and gold nanoparticles, as well as microbeam RT and FLASH RT are discussed in this context. Then, a number of kV x-ray RT applications in modeling and proof-of-principle stages, such as breast external beam RT with rotational sources, kilovoltage arc therapy and the BriXS Compton pulsed x-ray sources, are reviewed. Finally, some clinical and economic considerations for the development of kV RT techniques are discussed.     

McMaster's pioneer in evidence-based medicine now spreading his message in England.

Dr. David Sackett, formerly of McMaster University and now at Oxford University in England, is considered one of the pioneers of the evidence-based medicine movement. This article looks at his colleagues'' assessment of Sackett''s contributions to medicine and at Sackett''s own views on his lengthy career.     

Sir William Osler revisited.

The basis of Sir William Osler''s fame is elusive to almost all and the appropriateness of such recognition is questioned by many. His many contributions as a practitioner, teacher, writer, and scientist in medicine do not adequately explain his prominence 60 years following his death. It was his participation in the covenant of medicine and the special components of that relationship that may account for his hold on his followers today.     

Clonogenic survival of human keratinocytes and rodent fibroblasts after irradiation with 25 kV x-rays

Low energy x-rays (E_ph 50 keV) are widely used in diagnostic radiology and radiotherapy. However, data on their relative biological effectiveness (RBE) are scarce. Of particular importance for risk estimation are the RBE values of x-rays in the range which is commonly used in mammography (10–30 keV). We have determined clonogenic survival after low-energy x-ray irradiation for three cell lines: primary human epidermal keratinocytes (HEKn), mouse fibroblasts (NIH/3T3) and Chinese hamster fibroblasts (V79). Experiments were performed with a 25 kV x-ray tube and compared to 200 kV x-rays as a reference. Compared to the effect of 200 kV x-rays, irradiation with 25 kV x-rays resulted in a decreased survival rate in the murine fibroblasts, but not in the human epithelial cell line. The RBE value was calculated for 10% surviving fraction. For HEKn cells, RBE was 1.33±0.27, for NIH/3T3 cells 1.25±0.07 and for V79 cells 1.10±0.09, respectively. No consistently increased RBE was observed in the various cell lines. Nevertheless, a potential of increased cytogenetic changes has to be considered for risk estimation of low-energy x-rays.     

The impact of a new geriatric program in a hospital for the chronically ill.

Reports of the rapidly increasing proportion of persons aged 65 years and more in Canada and the resultant need for changes in the country''s health care system prompted experimental changes in the operation and training procedures at St. Mary''s of the Lake Hospital, Kingston, Ont. Aimed at better patient care and at better education of medical house staff in geriatrics and long-term care, the revised program is permeated with the philosophy of rehabilitation. It includes full-time staff, a geriatric outpatient clinic, a day hospital, a team approach to patient care (with regular team audits), problem-oriented medical records, a formal physical medicine section with a district inpatient unit, and an intensive inservice education program. After the first year of the program patient outcome had improved and more efficient use was being made of continuing care beds because of larger numbers of patinets being discharged home after shorter stays. This may be one avenue for deceleration of our country''s dismal rate of institutionalization.     

Canadians pay for harsh economic policies with their health,physicians warn.

Canada''s fiscal policies are damaging the health of Canadians, two physicians told a conference that examined globalization''s impact on the country. Near-record unemployment levels and the recent recession have forced 41% of families in which the parents are 30 or younger to live below the poverty level; more than 21% of Canadian children are also considered to live in poverty. The impact tight fiscal policies have on health and well-being are enormous, say the dean of medicine at the University of Western Ontario and the chair of the Canadian Institute of Child Health.     

Alfred R. Wallace's enduring influence on biogeographical studies of the Indo-Australian archipelago

To mark A.R. Wallace's 200th birthday, we review the direct and indirect contributions he made to our understanding of the Indo-Australian Archipelago's biogeography. He is widely known for his field research (1854–1862) and his 1863 boundary line separating the Oriental and Australasian faunal realms (between Bali and Lombok, Borneo and Sulawesi, and the Philippines and the Moluccas). Notably, though, he never accepted Huxley's ‘Wallace Line’ proposal (1868), whose northern part runs between the main Philippine islands and the Palawan Group to the west. Furthermore, in 1910, which was 3 years prior to his demise, he transferred Sulawesi's fauna to the Oriental realm. In 1924, Merrill introduced the ‘Wallacea’ transition zone. Although the label is today widely used to denote a sub-region within the Indo-Australian Archipelago between Wallace's 1863 line and Lydekker's 1896 line (first presented by Darlington in 1957), the western boundary was originally based on Huxley's line, and thus included the Philippine islands minus the Palawan group. Most biogeographers appear to be unaware of Merrill and his intention. Finally, recent attempts to define the faunal break have not led to a consensus view, despite the huge increase in primary data plus the application of modern analytical techniques. This reflects the complexities and diversity of the region's faunal distribution patterns, plus the differences in the ways that researchers choose to process their data.     

The pathogenesis of diabetes mellitus. Possible usefulness of spontaneous hyperglycemic syndromes in animals.

Systematic studies of the patterns of anatomic distribution, pathways of probable spread, and prognosis of the malignant lymphomas have been greatly aided by the development of new histopathologic classifications and the introduction of more sophisticated and precise diagnostic techniques, such as lymphangiography and laparotomy with splenectomy and retroperitoneal node biopsy. Concomitantly, megavoltage radiotherapy apparatus has made total-lymphoid radiotherapy feasible and practical, and the availability of a widening spectrum of chemotherapeutic agents has ushered in a new era of combination chemotherapy. Collectively, these diagnostic and therapeutic advances have already begun to yield a dramatic improvement in the prognosis of Hodgkin''s disease and the other malignant lymphomas.     

Spectroscopic Studies of Carboxypeptidase: the Work of Bert L. Vallee

The Role of Zinc in Carboxypeptidase (Vallee, B. L., Rupley, J. A., Coombs, T. L., and Neurath, H. (1960) J. Biol. Chem. 235, 64–69)Metallocarboxypeptidases (Coleman, J. E., and Vallee, B. L. (1960) J. Biol. Chem. 235, 390–395)Bert Lester Vallee (1919–2010) was born in Germany and grew up in Luxembourg. He received his B.S. in 1938 from the University of Bern in Switzerland, after which he came to the United States as the first (and only) fellow of the League of United Nations International Student Service. He was admitted to New York University and worked with Richard Courant, receiving his M.D. from the New York University College of Medicine in 1943.Open in a separate windowBert L. ValleeDuring World War II, Vallee was assigned to the joint Harvard Medical School-MIT blood preservation project, directed by Journal of Biological Chemistry (JBC) Classic authors Edwin Cohn (1) and John Edsall (2). This experience shaped Vallee''s future career in biochemistry and biophysics. At MIT, he became interested in the metabolism of iron and other metals such as zinc and copper. Little was known about this topic at the time, and he recognized the potential of spectroscopy, particularly emission and arc spectroscopy, for the detection of metals in biological systems. He decided to focus his research on the subject and was awarded a National Research Council Fellowship to pursue these studies in the physics and biology departments at MIT under the direction of John R. Loofbourow and George R. Harrison.In 1954, Vallee joined the faculty of Harvard Medical School where he established the Biophysics Research Laboratory. He was named assistant professor of medicine in 1956 and rose swiftly through the ranks to become the Paul C. Cabot Professor of Biological Chemistry in 1965 and the Edgar M. Bronfman Distinguished Senior Professor in 1980 (a title he held until his death in 2010).At Harvard, Vallee continued the work that he initiated at MIT, focusing on the design and construction of new spectrochemical instruments for use in biology. He built a flame spectrometer to detect and quantify sodium, potassium, magnesium, and calcium in biological samples. At that time, these elements could not be measured accurately in physiological concentrations. This early spectrometer became the prototype for later instruments capable of monitoring these elements in clinical samples.Vallee''s laboratory soon became a world center for the analysis of trace metals in biological samples. He continued his efforts to define, develop, and evaluate new spectroscopic flame sources for the excitation and spectral emission of atoms and to make biological spectroscopy an intrinsic part of modern biological and medical science. Because of his work on the role of metals in biological systems, many consider him to be the “father of metallobiochemistry.”Vallee''s own research centered on the identification of zinc in various metalloproteins and enzymes. One of the many zinc proteins he studied was carboxypeptidase. Vallee carried out careful and extensive mechanistic studies of the enzyme using spectroscopy, stopped-flow kinetics, and chemical modification. He was able not only to elucidate its reaction mechanism but also to provide structural information on the enzyme, including particular roles of specific amino acids. When the x-ray structure of carboxypeptidase was ultimately deduced, Vallee''s results proved to be remarkably accurate.The two JBC Classics reprinted here were both published in 1960 and contain some of Vallee''s early observations on carboxypeptidase. In the first Classic, Vallee and several of his colleagues, including JBC Classic author Hans Neurath (3), examined the roll of zinc in carboxypeptidase. Vallee and Neurath had previously determined that each carboxypeptidase molecule contained one atom of zinc and that the zinc was necessary for enzymatic activity (4). They followed up these initial observations by showing that enzymatic activity lost by zinc dialysis is exactly proportional to the amount of zinc removed. They also discovered that the loss of activity could be reversed by the addition of zinc and several other ions, including Cr³⁺, Ni²⁺, Co²⁺, Fe²⁺, and Mn²⁺.Later that year, Vallee and Joseph E. Coleman published the second JBC Classic, which explores the relationship between pH and the restoration of activity by the addition of metal ions to carboxypeptidase. Vallee discovered that the degree to which activity is restored is a critical function of pH. Because pH could influence enzymatic activity either by affecting the binding of the metal to the apoenzyme or by influencing the rate of catalysis, Vallee and Coleman attempted to separate these two effects by exposing the enzyme to the metal ions at a given pH but assaying it under standard conditions at pH 7.5. They determined that the restoration of activity was a direct function of the binding of metal to the apoprotein. They also learned that the apoenzyme had at least two binding sites for metals but that only one of the sites was essential for activity.Vallee also studied the zinc-containing alcohol dehydrogenase and the role the enzyme plays in alcohol metabolism and alcohol addiction. He showed that genetics are an important determinant of alcoholism, and his work has led to clinical trials of drugs for the treatment of this disease, including daidzin, which he isolated from the kudzu plant.Since Vallee started working on zinc-containing proteins, scientists have found that up to 10% of the human proteome may be composed of zinc proteins, and as of April 2007, there are nearly 400 x-ray and NMR structures of zinc proteins available.Vallee was widely recognized for his scientific achievements. He received many awards, including the Warner-Chilcott Award (1969), the Linderstrom-Lang Medal (1980), the Willard Gibbs Medal from the American Chemical Society (1981), and the William C. Rose Award from the American Society for Biochemistry and Molecular Biology (1982). He also was elected to the National Academy of Sciences and the American Academy of Arts and Sciences. Wanting to give back to science, Vallee and his wife established the Vallee Foundation to foster originality, creativity, and leadership in science. The Foundation funds honorary Vallee Professorships, which allow accomplished scientists to explore new areas and to establish close interactions with other successful senior investigators that might lead to new knowledge.     

"I won't do surgery if you don't try to do my job," head of new blood agency tells MDs

Ken Fyke is known as a tough administrator, and he is going to need all of his administrative tricks as first chair of Canadian Blood Services, the new national organization that is taking over responsibility for the nation''s blood supply from the Red Cross come September. Fyke says he hopes to work closely with physicians, but they will have to realize where their responsibilities end and his begin.     

The Oslerian Tradition and Changing Medical Education: A Reappraisal

Although only 21 of Sir William Osler''s 45 years in academic medicine were spent in US medical schools (1884 to 1905), he played a major role in shaping modern medical education in this country. The integration of scholarship with patient care, together with the science and art of medicine, was central to Osler''s teaching and writing throughout his career. A classic generalist and a charismatic clinical teacher, he taught by example and was as concerned with the ideals of medicine as with its science and knowledge.Many changes have reshaped the content, process and concerns of American medical education since Osler''s time. Subspecialization and balkanization of medical education and practice have become dominant. Many of the important issues in medicine today do not fit neatly into the domain of any of the established specialties or medical organizations. There is now an urgent need to promote generalist attitudes in medicine, and the Oslerian tradition has much to offer in approaching today''s problems in medical education and practice.     

Research of a holiday kind: One giant leap for mankind? A cost-utility analysis of abolishing the law of gravity

Background

Canada''s Neo Rhino Party, a joke political party created in 2006 as a successor to the Parti Rhinocéros, is planning a new regulation to repeal the law of gravity, which could have an important impact on diseases attributable to gravity on earth.

Methods

We sought to estimate the number of quality-adjusted life-years that would be saved if the proposed regulation is passed and determine the cost-effectiveness of adapting Boris Volfson''s antigravity machine¹ for use on earth. We performed an economic analysis using a hidden Markov model.

Results

Our results suggest that a microgravity environment would save over 2 million quality-adjusted life-years. The cost for every quality-adjusted life-year saved is estimated to be $328.

Interpretation

Microgravity is the solution to the health care crisis in Canada. In addition, using technological, statistical and medical jargon gives us the opportunity to defy the laws of physics, mathematics and medicine.Canada''s Neo Rhino Party is a joke federal political party that was created in Montréal, Quebec, in 2006 as the successor to the Parti Rhinocéros. Commonly called the Rhinoceros Party in English, this party was a registered political party in Canada from the 1960s to the 1990s. It was founded in 1963 by Jacques Ferron, a Canadian physician and author. The party''s basic credo was “a promise to keep none of our promises.” Its election platforms comprised impossible schemes that were designed to amuse and entertain the voting public. Some Rhinoceros Party promises included reducing the speed of light because it''s much too fast, paving Manitoba to create the world''s largest parking lot, providing higher education by building taller schools and repealing the law of gravity. When this last promise was made in the 1980s, it was unthinkable, that is, until Boris Volfson of Huntington, Indiana, received US Patent 6 960 975 for his design of an antigravity machine.¹ The Neo Rhino Party is currently planning a new regulation to repeal the law of gravity that could have an important impact on diseases and other health outcomes attributable to gravity on earth.     

McGill-trained MD,experiment give June 20 shuttle flight strong Canadian flavour.

Family physician Robert Thirsk, an original member of the Canadian Space Agency''s astronaut program, will be part of the seven-member crew when the space shuttle Columbia lifts off from Florida''s Kennedy Space Centre June 20. In this special report, the 1982 McGill graduate outlines some of the physiologic and materials-science experiments the crew will conduct. Thirsk, a payload specialist and crew medical officer, thinks the findings could have a significant impact on future space missions, medicine and the biotechnology industry.     

EXPERIMENTALLY INDUCED CHROMOSOME ABERRATIONS IN PLANTS : II. THE EFFECT OF CYANIDE AND OTHER HEAVY METAL COMPLEXING AGENTS ON THE PRODUCTION OF CHROMOSOME ABERRATIONS BY X-RAYS

The discovery of Lilly and Thoday, that the presence of potassium cyanide (KCN) increases the production of chromosome aberrations by x-rays in anoxia, but has no effect on the production of chromosome aberrations by x-rays in air, was confirmed. In the presence of cyanide, the effect of a given dose of x-rays in nitrogen was found to be even greater than the effect of the same dose of x-rays in air. The cyanide effect on x-ray breakage in nitrogen was obtained at cyanide concentrations as low as 2 x 10^–5 M. The breakage obtained after the combined x-ray-cyanide treatments was of the x-ray type, as evidenced by the distribution of breaks within and between the chromosomes. A number of other heavy metal complexing agents as well as some other compounds were tested for their ability to increase x-ray breakage in nitrogen and air. Of these compounds only cupferron proved to be effective. The results are discussed and it is concluded that the increased x-ray breakage in the presence of cyanide or cupferron cannot be due to an accumulation of peroxides. Instead it is suggested that the cyanide effect may be due to a complex formation between the active agents and heavy metals, presumably iron, within the chromosomes. The consequences of this hypothesis on the concept of the "oxygen effect," are discussed.