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Biomedical subjects

Robert Martindale

Publications and source records attributed to Robert Martindale.

9 recordsLinked to original sources

An anti-tumor role for cGMP-dependent protein kinase.

This study compared Type-1 cGMP-dependent protein kinase (PKG) expression in normal and tumor tissues and examined PKG function in tumor growth. Studies with a cDNA array revealed that PKG expression was reduced in many tumors compared to respective normal tissue. This decrease in PKG expression was confirmed using quantitative RT-PCR and western blotting of matched colon specimens from normal epithelium and tumor tissue, and also in colon derived cell lines where luciferase reporter analysis revealed that the decreased expression occurred at the transcriptional level. Using SW620 colon carcinoma cells engineered for inducible expression of PKG1beta, it was found that exogenous PKG1beta lead to decreased tumor growth and invasiveness in nude mouse xenografts.

Adenocarcinoma↗

Prebiotics and synbiotics in clinical medicine.

Pharmaceutical medicine has thus far been unable to stop the increasing global morbidity and mortality both in acute and chronic diseases. Typically, medical practice has focused on reducing the aggressor with treatments such as antibiotics; little interest has been given to efforts to increase the individual's resistance to disease. The increased morbidity has occurred in parallel to a deviation from a large consumption of fresh fruits, vegetables, and tubers rich in live lactic acid bacteria (LAB), plant fibers, and natural antioxidants to an industry-produced diet rich in fat and refined sugar but containing little fiber, antioxidants, and LAB. Plant fiber/prebiotics, plant-derived antioxidants, and LAB/probiotics are known to have the potential to reinforce the immune system of the body and increase resistance to disease. However, this depends on the type of fiber, antioxidant, and strain or combination of strain used. At this stage, only about 10% of the LAB studied have proven strong immunosupportive effects. Similarly, only a few plants contain what has been called superantioxidants, antioxidants 10 or more times stronger than vitamin C and E. Increasing evidence suggests that combining several probiotic bacteria into multistrain probiotics will achieve stronger effects than single-strain probiotics. And combining probiotics and prebiotics into "synbiotics" will further enhance the immunosupportive effects. There is little evidence that a single-strain-based "superprobiotic"/magic LAB will ever be found. Instead, combining several specific and defined probiotics and several key plant fibers into multistrain/multifiber synbiotics appears to be the most promising alternative. Some edge-cutting effects from using multistrain and multifiber compositions are reported both from animal and controlled clinical studies.

Dietary Fiber↗

Probiotics: a practical review of their role in specific clinical scenarios.

The use of probiotics (live viable microbial organisms) in the treatment of specific diseases has evolved into an extremely valuable option yet to be optimally used in clinical medicine. Probiotics have been shown to have immunomodulating properties and enhance the mucosal barrier. This review will briefly discuss the use of probiotics in inflammatory bowel disease, pancreatitis, liver transplantation, and various uses in diarrhea. When using probiotics, one must be cautious of the sometime overzealous claims that are commonly made when dealing with medical foods. As we begin to appreciate the degree of complexity that our indigenous microbial population has on health, it is only then that we can begin to understand the importance in disease. In the arena of probiotics, numerous fundamental questions remain unanswered.

Diarrhea↗

Bedside placement of small bowel feeding tubes in hospitalized patients: a new role for the dietitian.

OBJECTIVE: The benefits of enteral nutrition when compared with parenteral nutrition are well established. However, provision of enteral nutrition may not occur for several reasons, including lack of optimal feeding access. Gastric feeding is easier to initiate, but many hospitalized patients are intolerant to gastric feeding, although they can tolerate small bowel feeding. Many institutions rely on costly methods for placing small bowel feeding tubes. Our goal was to evaluate the effectiveness of a hospital-developed protocol for bedside-blind placement of postpyloric feeding tubes. METHODS: The Surgical Nutrition Service established a protocol for bedside placement of small bowel feeding tubes. The protocol uses a 10- or 12-French, 110-cm stylet containing the feeding tube; 10 mg of intravenous metoclopramide; gradual tube advancement followed by air injection and auscultation; and an abdominal radiograph for tube position confirmation. In a prospective manner, consults received by the surgical nutrition dietitian for feeding tube placements were followed consecutively for a 10-mo period. The registered dietitian recorded the number of radiograph examinations, the final tube position, and the time it took to achieve tube placement. RESULTS: Because all consults were included, feeding tube placements occurred in surgical and medical patients in the intensive care unit and on the ward. Of the 135 tube placements performed, 129 (95%) were successfully placed postpylorically, with 84% (114 of 135) placed at or beyond D3. Average time for tube placement was 28 min (10 to 90 min). One radiograph was required for 92% of the placements; eight of 135 (6%) required two radiographs. No acute complications were associated with the tube placements. CONCLUSIONS: Hospitalized patients can receive timely enteral feeding with a cost-effective feeding tube placement protocol. The protocol is easy to implement and can be taught to appropriate medical team members through proper training and certification.

Cost-Benefit Analysis↗

The gastrointestinal tract in critical illness: nutritional implications.

PURPOSE OF REVIEW: Recognition that the gastrointestinal tract is a key element of the immune system has led to a greater interest in understanding its role as a central figure in host defenses. Biologic systems that are perturbed by any destabilizing stimulus are known to respond by adaptive strategies in an attempt to maintain or return to global homeostasis. In critically ill patients, the gut has previously been described as a promoter of progression to sepsis and multi-organ failure. However, with better understanding of gastrointestinal tract mucosal immunity, we are now provided with a new arsenal to combat nosocomial infection and significantly impact return to health. RECENT FINDINGS: In this review we focus on five key topics in the rapidly expanding landscape of knowledge on the gastrointestinal tract in the critical care setting. These include a discussion of probiotic therapy, now the new frontier of immuno-nutrition, the concept of ischemia/reperfusion injury and changes in gut permeability, anti-oxidant and micronutrient therapy, blood glucose regulation, and enhancement of gut motility, all in the intensive care setting. SUMMARY: Ongoing research in nutritional support in both normal and pathologic gastrointestinal function and response to injury has opened the door to several new opportunities for enhancing rapid recovery in critical care.

Antioxidants↗

The clear liquid diet: when is it appropriate?

Closer attention to the clear liquid diet and its therapeutic applications has been prompted by critical reviews of nutritional enhancement in the clinical environment. The aim of ongoing research has been to uncover the optimal nutrient complement in various patient groups as well as the most beneficial mode of nutrient delivery. Route of feeding is often the essential determinant in effectiveness of nutritional support. Many studies have sought to demonstrate the superiority of enteral versus parenteral nutrition, whereas comparative studies with clear liquid diets are sparse. Recently, identification of key nutrients in the support of malnourished or immunocompromised patients has been emphasized. Although total parenteral nutrition has undisputed applications in specific patient groups, it has lost favor for general application because of its negative impact on immunocompetence. Efforts have thus been redoubled to explore the potential of the gastrointestinal tract, with the derived benefit in immunosupport for many medical and surgical disease states. Until recently, the clear liquid diet had not received close scrutiny and had retained an unchallenged position in certain applications (eg, bowel preparation). This paper summarizes the published, theorized, and potential benefits as well as the limitations of the clear liquid diet.

Enteral Nutrition↗

Is the use of specialized nutritional formulations a cost-effective strategy? A national database evaluation.

BACKGROUND: We apply currently published clinical outcomes data to length of stay and hospital cost to determine the potential economic benefit associated with the use of specialized nutritional formulations in elective surgical, trauma, and medical patients. Although the use of immune-modulating formulations has repeatedly shown favorable clinical outcomes, including decreased complications (both infectious and noninfectious), length of stay (both ICU and total days), and ventilator days, the cost-effectiveness of nutritional modulation of the immune response in a US-based population has not previously been explored. METHODS: Data for the current study were obtained from a large national database with 126 member hospitals and data from over 1 million patients. Data extracted from the database included patient type (surgical, medical, and trauma) and subservice, whether the hospital stay was "complicated" or "uncomplicated" (as determined by diagnosis-related groups and International Classification of Diseases, Ninth Revision coding), mean length of stay, mean cost, and incremental cost per complication experienced. The clinical outcomes measures from 3 major peer-reviewed studies were then applied to the cost data in order to determine the cost savings associated with the use of specialized nutritional formulations in each of the patient populations. Additionally, cost data were segmented by region of the United States (New England, mid-Atlantic, South, Midwest, Southwest, and West) and by primary focus of the health care facility (academic, indigent care, large community) to enable more meaningful cost comparisons. RESULTS: For the medical patient population, according to the published rate of 51% decrease in risk of infectious complications and a decreased length of hospital stay of 9.7 days, net cost savings (after accounting for the increased costs of administering immune modulating formula) is $2066. The same calculations were done for surgical and trauma patients, with $688 and $308 net cost savings per patient, respectively. These figures assume a base infection rate of 5%. Expected cost savings vary markedly for deviations in base infection rate and slightly for differences in facility type or region of the country. CONCLUSIONS: This study demonstrates that specialized nutritional formulations are a cost-effective way for hospitals to improve clinical outcomes while reducing resource consumption and total cost. These benefits are observable in all patient types, all facility types, and all regions of the United States.

Cost-Benefit Analysis↗