Biomedical subjects
Publications and source records attributed to W T Jarvis.
The use of a Fogarty catheter to dilate a constricted flexor sheath is described. This relatively atraumatic method of dilating a constricted flexor sheath, may sometimes allow a one-stage rather than a two-stage tendon graft procedure.
Quackery is the promotion of false and unproven health schemes for a profit. It is rooted in the traditions of marketplace. Scientific thinking and standards of conduct underlie professionalism and consumer protection law. At the present time, commercialism has overwhelmed professionalism in the marketing of alternative remedies. Neither patients nor legitimate businesses that adhere to the standards of science and consumer protection are well served by a double standard.
Food and nutrition experts, including ADA members, need to take an active role in helping consumers recognize misinformation. The challenge of dealing with food and nutrition misinformation is long-standing and persistent. However, qualified dietetics professionals, in partnership with other members of the health-care team, educators, and representatives of the food industry, can be a forceful voice against food and nutrition misinformation. Qualified dietetics professionals can positively shape the food choices of Americans by collaborating with the media to communicate balanced nutrition information to consumers and to counter misinformation; writing letters to the editors of newspapers and magazines to counter inaccurate and biased articles; calling television and radio shows that interview nutrition extremists and purveyors of misinformation to express their professional concerns; directing the news media and consumers to responsible sources of nutrition information; encouraging researchers to present their results with a balanced perspective; collaborating with the food industry to provide reliable nutrition information; and cooperating with other practitioners to expose emerging misinformation, misbeliefs, frauds, and quackery before they are widely accepted.
Explore the source record for details and available documents.
The U.S. Congress determined quackery to be the most harmful consumer fraud against elderly people. Americans waste $27 billion annually on questionable health care, exceeding the amount spent on biomedical research. Quackery is characterized by the promotion of false and unproven health schemes for profit and does not necessarily involve imposture, fraud, or greed. The real issues in the war against quackery are the principles, including scientific rationale, encoded into consumer protection laws, primarily the U.S. Food, Drug, and Cosmetic Act. More such laws are badly needed. Regulators are failing the public by enforcing laws inadequately, applying double standards, and accrediting pseudomedicine. Non-scientific health care (e.g., acupuncture, ayurvedic medicine, chiropractic, homeopathy, naturopathy) is licensed by individual states. Practitioners use unscientific practices and deception on a public who, lacking complex health-care knowledge, must rely upon the trustworthiness of providers. Quackery not only harms people, it undermines the scientific enterprise and should be actively opposed by every scientist.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1. A series of d-galactose derivatives substituted at C-1 and C-6 were tested for active accumulation by everted segments of hamster and rat intestine. 2. d-Galactose and 6-deoxy-6-fluoro-d-galactose were accumulated far more rapidly than 6-deoxy- and 6-chloro-6-deoxy-d-galactose, and this is interpreted as due to hydrogen-bonding at C-6 during the transport process. 3. 6-Bromo-6-deoxy- and 6-deoxy-6-iodo-d-galactose were not actively transported, indicating that the allowed size of substituent at C-6 lies between that of chlorine and bromine atoms. 4. Similar results were obtained at C-1. Both methyl alpha-d-galactopyranoside and methyl beta-d-galactopyranoside were well transported, but methyl beta-d-thiogalactopyranoside and 1-deoxy-d-galactose were not transported; d-galactopyranosyl fluoride was transported, but only poorly. Again hydrogen-bonding is suggested. 5. It is proposed that d-glucose is the ideal structure for active transport and that binding occurs at C-1, C-2, C-3, C-4 and C-6. Loss of two or more of these bonds usually causes loss of active transport. 6. By plotting Lineweaver-Burk plots of the rates of transport of the galactose derivatives, the apparent V and K(m) values were obtained. With hamster intestine both these values were very reproducible. Contrary to expectation, V varied for different sugars. 7. The K(i) of some of the analogues modified at C-1 and C-6 was determined with methyl alpha-d-glucoside as substrate. 8. An attempt to alkylate the carrier by using methyl 3,4-anhydro-alpha-d-galactoside was unsuccessful. There was no evidence that this compound was bound to the carrier.
1. alpha-d-Glucosyl fluoride was hydrolysed by an extract of rat intestinal mucosa. The pH optimum was 6.6 and the K(m) 0.4mm at 20 degrees . Activity was assayed by release of either glucose or fluoride. 2. The alpha-d-glucosyl fluoride-hydrolase activity of the extract was associated with both mutarotase and alpha-d-glucosidase activities. 3. Tris (5mm) inhibited both the alpha-d-glucosidase and alpha-d-glucosyl fluoride-hydrolase activities by 55% but did not inhibit mutarotase. The K(i) of tris for both enzyme activities was 2mm. 4. The extract did not hydrolyse melibiose and lactose. Mutarotase used both alpha-d-glucose and beta-l-arabinose as substrates but the glucosyl fluoride-hydrolase activity did not extend to beta-l-arabinosyl fluoride. 5. The thermal stability of alpha-d-glucosidase and alpha-d-glucosyl fluoride hydrolase was identical. Mutarotase was more thermolabile. 6. A preparation of the brush border of intestinal epithelial cells contained both alpha-d-glucosyl fluoride-hydrolase and alpha-d-glucosidase activities. In each precipitate and washing the ratio of the two activities was the same. All the mutarotase activity was in the first supernatant. 7. Agidex, a fungal amyloglucosidase, cleaved glucosyl fluoride in addition to maltose. Tris inhibited both activities and in each case the K(i) was 3mm. 8. The probable identity of alpha-d-glucosyl fluoride hydrolase with alpha-d-glucosidase is discussed and a possible mechanism for the reaction suggested. 9. Incubation of intestinal slices with alpha-d-glucosyl fluoride led to complete hydrolysis in 30min. The glucose rapidly entered the cell and was metabolized, leaving the fluoride in the incubation medium. This constitutes a further proof that the intestinal alpha-d-glucosidase, although on the brush border, is located outside the site of active transport of sugars.
1. alpha-d- and beta-d-Glucopyranosyl, alpha-d- and beta-d-galactopyranosyl, alpha-d-mannopyranosyl and alpha-d-xylopyranosyl fluorides were hydrolysed specifically by the respective glycosidases from several sources. 2. Use of specific inhibitors with a mixture of glycosidases from Helix pomatia intestinal juice showed that each glycosyl fluoride was hydrolysed only by the respective glycosidase. alpha-d-Glucopyranosidase and alpha-d-xylopyranosidase activities were shown to be due to different enzymes. 3. Partially purified enzyme preparations containing only one of the glycosidase activities hydrolysed only the corresponding glycosyl fluoride. 4. The configuration at C-1 of alpha-d-mannopyranosyl fluoride was confirmed since it was hydrolysed by an alpha-d-mannosidase preparation that contained no detectable beta-d-mannosidase activity. 5. An attempt to prepare o-nitrophenyl beta-d-mannopyranoside led only to o-nitrophenyl alpha-d-mannopyranoside.