scispace - formally typeset
Search or ask a question
Author

John P. Williams

Bio: John P. Williams is an academic researcher from University of Alabama at Birmingham. The author has contributed to research in topics: Calmodulin & Osteoclast. The author has an hindex of 12, co-authored 18 publications receiving 513 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: It is concluded that glucose is the principal energy source required for bone degradation, and characteristics of glucose transport are consistent with the hypothesis that fluctuations in serum glucose concentration are an important component in regulation of osteoclastic bone degradation.

102 citations

Journal ArticleDOI
TL;DR: It might be possible to reduce the "burden of treatment" identified by incorporating a structured approach to patient monitoring and by reviewing the occupational territories of specialist and non-specialist practitioners.
Abstract: Aim. This paper reports a study of patients’ experiences of this relatively new technology, and explores possible strategies for defining, delineating and addressing patients’ concerns, problems and needs. Background. The number of patients in the community relying on percutaneous endoscopic gastrostomy for their nutritional needs is increasing, but percutaneous endoscopic gastrostomy feeding is not problem-free. However, few studies report on its impact from a patient perspective. Methods. Twenty adults with long-term percutaneous endoscopic gastrostomies were interviewed in their own homes, using both semi-structured and structured approaches. Qualitative data were analysed thematically and related to a symptom checklist and an established quality of life measure, the Short Form-12. Findings. Most participants felt that insertion of a percutaneous endoscopic gastrostomy had been life-saving, but found that percutaneous endoscopic gastrostomy feeding came to dominate their lives and was associated with an appreciable ‘burden of treatment’. Some, but not all, of the problems recounted were unavoidable: percutaneous endoscopic gastrostomy feeding inevitably imposed physical restrictions on mobility; 17/20 participants had experienced serious technical problems with their percutaneous endoscopic gastrostomy tubes. On structured questioning, all interviewees had some, potentially treatable, gastrointestinal symptoms, and eight had continuous problems. In some cases, the burden of treatment was exaggerated by being unanticipated and, for 13 patients, difficulties with care provided by non-specialist services. Describing this ‘burden of treatment’ for each patient required both a narrative and a structured approach: without the symptom checklists, some important and treatable problems were missed. Both physical and mental health Short Form-12 scores were low, and mental health scores were congruent with the interview data. Conclusions. It might be possible to reduce the ‘burden of treatment’ identified by incorporating a structured approach to patient monitoring and by reviewing the occupational territories of specialist and non-specialist practitioners. Further research with larger numbers of participants is needed to explore the integration of narrative and quantitative data when determining patients’ clinical needs.

66 citations

Journal ArticleDOI
TL;DR: It is concluded that tyrosine kinase inhibition directly inhibits osteoclast membrane hydrochloric acid transport; differences among inhibitors may reflect chemical reactivity and permeability.

50 citations

Journal ArticleDOI
TL;DR: The data indicate that gp160-enhanced apoptosis is dependent upon cal modulin up-regulation, involves the activation of caspase 3, and requires calmodulin binding to the C-terminal binding domain of gp160.

47 citations

Journal ArticleDOI
TL;DR: In this article, the effects of tamoxifen, 4-hydroxytamoxifier, trifluoperazine and calmidazolium on 3H-labeled bone in vitro and on membrane HCl transport were investigated.

43 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: It is now apparent that there are two distinct subpopulations of people and that "bacterio-typing" individuals for their ability to make equol may hold the clue to the effectiveness of soy protein diets in the treatment or prevention of hormone-dependent conditions.
Abstract: Equol [7-hydroxy-3-(4'-hydroxyphenyl)-chroman] is a nonsteroidal estrogen of the isoflavone class. It is exclusively a product of intestinal bacterial metabolism of dietary isoflavones and it possesses estrogenic activity, having affinity for both estrogen receptors, ERalpha and ERbeta. Equol is superior to all other isoflavones in its antioxidant activity. It is the end product of the biotransformation of the phytoestrogen daidzein, one of the two main isoflavones found in abundance in soybeans and most soy foods. Once formed, it is relatively stable; however, equol is not produced in all healthy adults in response to dietary challenge with soy or daidzein. Several recent dietary intervention studies examining the health effects of soy isoflavones allude to the potential importance of equol by establishing that maximal clinical responses to soy protein diets are observed in people who are good "equol-producers." It is now apparent that there are two distinct subpopulations of people and that "bacterio-typing" individuals for their ability to make equol may hold the clue to the effectiveness of soy protein diets in the treatment or prevention of hormone-dependent conditions. In reviewing the history of equol, its biological properties, factors influencing its formation and clinical data, we propose a new paradigm. The clinical effectiveness of soy protein in cardiovascular, bone and menopausal health may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic isoflavone, equol. The failure to distinguish those subjects who are "equol-producers" from "nonequol producers" in previous clinical studies could plausibly explain the variance in reported data on the health benefits of soy.

1,143 citations

Journal ArticleDOI
TL;DR: The major diseases of bone remodeling are reviewed, emphasizing the current understanding of the underlying pathophysiological mechanisms.
Abstract: The skeleton provides mechanical support for stature and locomotion, protects vital organs, and controls mineral homeostasis. A healthy skeleton must be maintained by constant bone modeling to carry out these crucial functions throughout life. Bone remodeling involves the removal of old or damaged bone by osteoclasts (bone resorption) and the subsequent replacement of new bone formed by osteoblasts (bone formation). Normal bone remodeling requires a tight coupling of bone resorption to bone formation to guarantee no alteration in bone mass or quality after each remodeling cycle. However, this important physiological process can be derailed by a variety of factors, including menopause-associated hormonal changes, age-related factors, changes in physical activity, drugs, and secondary diseases, which lead to the development of various bone disorders in both women and men. We review the major diseases of bone remodeling, emphasizing our current understanding of the underlying pathophysiological mechanisms.

875 citations

Journal ArticleDOI
TL;DR: A range of effective interventions is available to support adequate nutrition and hydration in older persons in order to maintain or improve nutritional status and improve clinical course and quality of life.

700 citations

Journal ArticleDOI
TL;DR: The role of dietary components on bone health throughout different stages of life is reviewed, however the fact that many nutrients are co-dependent and simultaneously interact with genetic and environmental factors should not be neglected.
Abstract: Osteoporosis is a complex, multi-factorial condition characterized by reduced bone mass and impaired micro-architectural structure, leading to an increased susceptibility to fractures. Although most of the bone strength (including bone mass and quality) is genetically determined, many other factors (nutritional, environmental and life-style) also influence bone. Nutrition is important modifiable factor in the development and maintenance of bone mass and the prevention and treatment of osteoporosis. Approximately 80-90% of bone mineral content is comprised of calcium and phosphorus. Other dietary components, such as protein, magnesium, zinc, copper, iron, fluoride, vitamins D, A, C, and K are required for normal bone metabolism, while other ingested compounds not usually categorized as nutrients (e.g. caffeine, alcohol, phytoestrogens) may also impact bone health. Unraveling the interaction between different factors; nutritional, environmental, life style, and heredity help us to understand the complexity of the development of osteoporosis and subsequent fractures. This paper reviews the role of dietary components on bone health throughout different stages of life. Each nutrient is discussed separately, however the fact that many nutrients are co-dependent and simultaneously interact with genetic and environmental factors should not be neglected. The complexity of the interactions is probably the reason why there are controversial or inconsistent findings regarding the contribution of a single or a group of nutrients in bone health.

516 citations

Journal ArticleDOI
TL;DR: Genetic data support a major role for the cytoplasmic tail of gp41 and the matrix domain of Gag in Env glycoprotein incorporation in HIV-1 Env incorporation and the role of specific membrane microdomains in this process is reviewed.

461 citations