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Biomedical subjects

R M Ford

Publications and source records attributed to R M Ford.

At least 19 recordsLinked to original sources
PubMed1992

Diagnosis and treatment of ossification of the posterior longitudinal ligament of the spine: report of eight cases and literature review.

PURPOSE: Ossification of the posterior longitudinal ligament (OPLL) is a common, well-recognized cause of spinal stenosis and myelopathy in Japan. Although also common in whites, especially among the elderly, it has received little scientific attention. We wish to increase awareness of this important cause of myelopathy, and to determine if the clinical characteristics of OPLL are similar in non-Japanese and Japanese patients. PATIENTS AND METHODS: The clinical and radiologic features of eight cases of OPLL are presented. These cases combined with 73 non-Japanese cases gathered from the English literature are contrasted with 2,125 Japanese cases of OPLL. RESULTS: Similarities among non-Japanese and Japanese cases included: (1) male predominance; (2) peak age at onset of symptoms in the sixth decade; (3) clinical presentation, which ranged from asymptomatic to quadriplegia, with progressive or acute onset of neurologic deterioration; (4) greater than 95% localization to the cervical spine, spastic quadriparesis being the most common neurologic presentation; (5) an association with several rheumatic conditions including diffuse idiopathic skeletal hyperostosis (DISH), spondylosis, and ankylosing spondylitis; and (6) neurologic improvement with either conservative or surgical treatment in a significant proportion of patients. Differences between the two groups were minimal and included a higher mean age at onset (although onset in both groups occurred within the sixth decade) and a greater proportion of patients with DISH and with the continuous type of OPLL in the non-Japanese group. CONCLUSION: The clinical characteristics of OPLL are similar in Japanese and non-Japanese patient populations. Increased awareness of this condition, which has potentially devastating neurologic complications, will favorably influence diagnosis, treatment, and outcome.

Adult↗
PubMed1992

A simple expression for quantifying bacterial chemotaxis using capillary assay data: application to the analysis of enhanced chemotactic responses from growth-limited cultures.

An individual cell-based mathematical model of Rivero et al. provides a framework for determining values of the chemotactic sensitivity coefficient chi 0, an intrinsic cell population parameter that characterizes the chemotactic response of bacterial populations. This coefficient can theoretically relate the swimming behavior of individual cells to the resulting migration of a bacterial population. When this model is applied to the commonly used capillary assay, an approximate solution can be obtained for a particular range of chemotactic strengths yielding a very simple analytical expression for estimating the value of chi 0, [formula: see text] from measurements of cell accumulation in the capillary, N, when attractant uptake is negligible. A0 and A infinity are the dimensionless attractant concentrations initially present at the mouth of the capillary and far into the capillary, respectively, which are scaled by Kd, the effective dissociation constant for receptor-attractant binding. D is the attractant diffusivity, and mu is the cell random motility coefficient. NRM is the cell accumulation in the capillary in the absence of an attractant gradient, from which mu can be determined independently as mu = (pi/4t)(NRM/pi r2bc)2, with r the capillary tube radius and bc the bacterial density initially in the chamber. When attractant uptake is significant, a slightly more involved procedure requiring a simple numerical integration becomes necessary. As an example, we apply this approach to quantitatively characterize, in terms of the chemotactic sensitivity coefficient chi 0, data from Terracciano indicating enhanced chemotactic responses of Escherichia coli to galactose when cultured under growth-limiting galactose levels in a chemostat.

Bacterial Physiological Phenomena↗
PubMed1991

Beta 2 agonists.

Explore the source record for details and available documents.

Adrenergic beta-Agonists↗
PubMed1991

Analysis of chemotactic bacterial distributions in population migration assays using a mathematical model applicable to steep or shallow attractant gradients.

The mathematical model developed by Rivero et al. (1989, Chem. Engng Sci. 44, 2881-2897) is applied to literature data measuring chemotactic bacterial population distributions in response to steep as well as shallow attractant gradients. This model is based on a fundamental picture of the sensing and response mechanisms of individual bacterial cells, and thus related individual cell properties such as swimming speed and tumbling frequency to population parameters such as the random motility coefficient and the chemotactic sensitivity coefficient. Numerical solution of the model equations generates predicted bacterial density and attractant concentration profiles for any given experimental assay. We have previously validated the mathematical model from experimental work involving a step change in the attractant gradient (Ford et al., 1991 Biotechnol. Bioengng, 37, 647-660; Ford and Lauffenburger, 1991, Biotechnol. Bioengng, 37, 661-672). Within the context of this experimental assay, effects of attractant diffusion and consumption, random motility, and chemotactic sensitivity on the shape of the profiles are explored to enhance our understanding of this complex phenomenon. We have applied this model to various other types of gradients with successful interpretation of data reported by Dalquist et al. (1972, Nature New Biol. 236, 120-123) for Salmonella typhimurium validating the mathematical model and supporting the involvement of high and low affinity receptors for serine chemotaxis by these cells.

Bacterial Physiological Phenomena↗
PubMed1979

Asthma: some basic methods of prevention.

Present traditional measures employed in the prevention of asthma are reviewed. It is recommended that in view of the extensive and possibly increasing prevalence of the disease together with continuing high death rates more attention in our treatment programs should be devoted to basic prevention in possibly susceptible people. High risk groups such as among small children, in certain industries and in developing counties make this approach especially desirable. An outline of suggested measures is presented.

Adolescent↗
PubMed1979

How do you recognize allergy?

A suggested basic approach to the diagnosis of allergic diseases, which involves the characteristics of allergic diseases themselves, is presented. Using these characteristics as basic guidelines in investigation, not only should the condition be diagnosed but main cause or causes and triggering factors should be demonstrated in individual patients. Investigational procedures ranging from history, and including simple skin tests and more sophisticated immunological investigations, are briefly analyzed and it is stressed that if a really adequate allergic investigation of all patients with suspect allergic disease is carried out in an effort to demonstrate and subsequently control all causes and triggering factors, then development of chronic disease, sometimes intractible to our standard methods of therapy, could well be prevented in many cases.

Humans↗
PubMed1978

Standardization of early drug trials in allergic diseases (with reference to a trial of doxantrazole).

Attention is drawn to the long wait in certain countries before new drugs and other therapies for the treatment of allergic diseases are approved by the local authorities, even when good trials with them have been carried out elsewhere. The main reasons for requiring repeat trials are poor original case selection and inadequate parameters of assessment, particularly environmental variations. The results of re-assessing patients who in the previous year had undergone a trial of a new chromoglycate-like drug (Doxantrazole) are used to illustrate the need to introduce standard basic requirements when new drugs and other agents are being tested in allergic diseases. A suggested format of such requirements is presented.

Bronchodilator Agents↗
PubMed1978

Primary lung cancer and asthma.

6,021 40-year-old and older chronic asthma suffers, seen during the past 20 years, were analyzed with regard to the development of primary lung cancer and their smoking habits. Over this period only two developed lung cancer, 0.032% as compared with 0.314% in the general population. Only 16.9% of chronic asthmatics had smoked over any significant period during the five years prior to assessment as compared with approximately 40% of the general population. Of those who did smoke, the tendency was to a lesser extent. This survey adds further evidence that cancer develops less frequently in patients suffering from an allergic disease such as asthma, perhaps because of (1) some enhanced immunological activity preventing the advent of new growth or (2) reduced smoking habits of chronic asthmatics.

Adult↗
PubMed1976

The prevention of asthma--some basic needs.

The present attitude in Australia towards the treatment of asthma is reviewed and attention is drawn to the need for employment of more basic methods of prevention. The disease is not just a chest condition but a manifestation, in many if not in most cases, of a generalized weakness of sensitivity- the bronchi are simply shock organs where much of the action takes place. A plea is also made for a reappraisal of teaching about asthma and related diseases at both undergraduate and postgraduate levels.

Adrenal Cortex Hormones↗
PubMed1976

Parallel variation of ventricular CSF tryptophan and free serum tryptophan in man.

Tryptophan was measured in the ventricular CSE and serum and the neutral amino acids leucine, isoleucine, valine, phenylalanine, and tyrosine were measured in the serum of two cases with ventricular drains. Samples were taken every two hours for 24 hours in one case and for 16 hours in the other. The CSF tryptophan was correlated significantly with the free--that is, non-albumin-bound--serum tryptophan but not with the total serum tryptophan. CSF tryptophan was not correlated significantly with the ratio of free serum tryptophan to the sum of the neutral amino acids. These data suggest that, in man, brain tryptophan concentrations are influenced by the free and not the total serum tryptophan and that physiological variations of the neutral amino acids do not appreciably influence the concentration of brain trytophan.

Adult↗
PubMed1976

Studies on cyclic AMP in different compartments of cerebrospinal fluid.

Adenosine 3', 5'-monophosphate (cAMP) was measured in the CSF of 42 patients undergoing radiological investigation, neurosurgical procedures, or investigation of hepatic coma. The concentration of cAMP was significantly higher in ventricular CSF than in lumbar CSF. Premedication with pentobarbitone plus promethazine increased cAMP in lumbar CSF. There was no difference in cAMP concentration in lumbar CSF obtained before or after injection of air or after the administration of diazepam during lumbar pneumoencephalography. Lumbar CSF cAMP concentration was significantly increased in patients in hepatic coma. The concentration of cAMP in the lateral ventricle was not affected by general anaesthesia or by the presence of a complete block of the aqueduct of Sylvius. There was no decrease in lumbar CSF cAMP in patients with a complete stenosis of the aqueduct of Sylvius, partial blocks of CSF flow at the cervical level, or a complete block at the lower thoracic level. The concentration of cisternal CSF cAMP was similar to that of lumbar CSF. These results suggest that (1) there is a ventriculolumbar gradient in the concentration of cAMP but of insufficient magnitude to be detected by mixing of lumbar and ventricular CSF during pneumoencephalography, (2) lumbar CSF cAMP concentration is not dependent on brain as a source of this nucleotide; the source of this nucleotide may be largely derived from the spinal cord, (3) premedication may affect the concentration of cAMP in lumbar CSF cAMP, (4) the formation of cAMP is unimpaired in hepatic coma.

Adult↗