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Biomedical subjects

J R Fox

Publications and source records attributed to J R Fox.

17 recordsLinked to original sources
PubMed2001

Biomechanical response to acupuncture needling in humans.

During acupuncture treatments, acupuncture needles are manipulated to elicit the characteristic "de qi" reaction widely viewed as essential to acupuncture's therapeutic effect. De qi has a biomechanical component, "needle grasp," which we have quantified by measuring the force necessary to pull an acupuncture needle out of the skin (pullout force) in 60 human subjects. We hypothesized that pullout force is greater with both bidirectional needle rotation (BI) and unidirectional rotation (UNI) than no rotation (NO). Acupuncture needles were inserted, manipulated, and pulled out by using a computer-controlled acupuncture needling instrument at eight acupuncture points and eight control points. We found 167 and 52% increases in mean pullout force with UNI and BI, respectively, compared with NO (repeated-measures ANOVA, P < 0.001). Pullout force was on average 18% greater at acupuncture points than at control points (P < 0.001). Needle grasp is therefore a measurable biomechanical phenomenon associated with acupuncture needle manipulation.

Acupuncture↗
PubMed2000

Today's approach to esophageal cancer. What is the role of the primary care physician?

Esophageal cancer is a devastating disease. Patients are most likely to first present to a primary care physician, who should immediately undertake an initial diagnostic and staging evaluation. The approach then should become multidisciplinary, involving surgical and medical oncologists, radiation oncologists, and gastroenterologists. Optimal therapy of esophageal cancer continues to evolve. While multimodality therapy remains controversial, studies are ongoing to determine the best approaches to improve survival. Further studies to define the role of surveillance endoscopy in certain high-risk patients are warranted.

Adenocarcinoma↗
PubMed1988

Precision and sensitivity of a test for vegetable fat adulteration of milk fat.

A test for routine screening of Mozzarella cheese and butter for vegetable fat adulteration is described. Fat is extracted and saponified. The potassium salts of the fatty acids are measured through direct gas chromatographic analysis. A ratio, calculated from the concentrations of butyric and oleic acids, is used to evaluate the purity of a sample. The test offers good precision and can detect less than 10% partially hydrogenated vegetable fat.

Butter↗
PubMed1988

Modification of the vermont test for monitoring fat adulteration of dairy products.

The Vermont test was developed for the routine screening of dairy products for vegetable fat adulteration. A slight modification of the test procedure made it more rapid and reduced costs. Gas-liquid chromatographic analysis of saponified fatty acids in the first and second Mojonnier extractions were proportional; thus, only the first extraction was needed to determine the purity of a milk lipid sample. This modification saves about 8 min/series of four samples and conserves 48% of the volume of organic solvents necessary to perform the classical Mojonnier extraction.

Butter↗
PubMed1980

Fogarty catheter removal of nasal foreign bodies.

The removal, without incident, of 14 nasal foreign bodies is described. None of the bodies was amenable to anterior instrumental extraction, and all were removed using a small-diameter Fogarty catheter.

Catheterization↗
PubMed1976

Ground substance mucopolysaccharides and plasma proteins: their role in capillary water balance.

The osmotic interaction of mucopolysaccharides and plasma proteins, normally present in the interstitium, has been investigated. It has been found that hyaluronate-plasma protein mixtures may be treated as a two-phase system and that the two phases are in osmotic equilibrium. The osmotic pressures exerted by these mixtures are higher than the algebraic sum of the two components. At concentrations normally present in the interstitium of skin and muscle (0.6% mucopolysaccharides and 2% protein), the osmotic pressure exerted by the mixture is on the order of 10 mmHg, which is in agreement with predictions from earlier computer-simulation studies. The partition of fluid between the gel-like mucopolysaccharide compartment and the free-fluid containing the protein is approximately 50% in the "gel" phase at concentrations found in the interstitium. The volume exclusion effects of the interstitial mucopolysaccharides are significant, both in terms of selection of tracer molecules for interstitial volume measurements and also as an osmotic buffering mechanism which aids in maintaining the partition of fluid between the circulation and the interstitial space.

Blood Proteins↗
PubMed1971

The dynamic response of brain temperature to localized heating.

Several mathematical descriptions of heat transport in perfused tissues have been proposed but have not been thoroughly tested under conditions of time-varying temperatures. Data was obtained by measuring the response of brain temperature to step changes in temperature of chronically implanted thermodes in conscious baboons. These responses were compared to numerical solutions of an equation expressing heat transport in terms of conduction in the tissue and convection due to capillary blood flow. Good agreement between experimental and theoretical curves was obtained for values of k (thermal diffusivity) of 0.0017-0.0021 cm(2)/sec and ø (blood flow per unit volume of tissue) of 0.3-0.7 cm(3)/cm(3)-min. The predicted temperature response at a given tissue location was not greatly affected either by changes in k and ø over the physiological range, or by small errors in describing experimental geometry. However, inaccuracies in describing boundary locations or failing to account for the relatively avascular scar tissue around the thermode changed the value of ø needed to fit the data by as much as 50%. Thus, we conclude that the model described in this paper can be used for a description of thermal gradients surrounding a thermode but extreme caution should be exercised if such a model is used to quantitatively evaluate blood flow.

Animals↗