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Biomedical subjects

Russell Jones

Publications and source records attributed to Russell Jones.

16 recordsLinked to original sources

Gastroduodenal intussusception due to gastrointestinal stromal tumor (GIST) treated by laparoscopic billroth II distal gastrectomy.

Gastrointestinal stromal tumors are rare tumors of the gastrointestinal tract. They, however, occur most commonly in the stomach where they present with abdominal pain, bleeding, and obstruction. Many are asymptomatic and are discovered incidentally or at postmortem. We present a case-report of a rare complication of gastrointestinal stromal tumors of the stomach causing gastroduodenal intussusception and how patient was successfully managed by laparoscopic Billroth II distal gastrectomy.

Aged, 80 and over↗

Nitric oxide accelerates seed germination in warm-season grasses.

The nitric oxide (NO) donor sodium nitroprusside (SNP) significantly promoted germination of switchgrass (Panicum virgatum L. cv Kanlow) in the light and in the dark at 25 degrees C, across a broad range of concentrations. SNP also promoted seed germination in two other warm-season grasses. A chemical scavenger of NO inhibited germination and blocked SNP stimulation of seed germination. The phenolic (+)-catechin acted synergistically with SNP and nitrite in promoting seed germination. Acidified nitrite, an alternate NO donor also significantly stimulated seed germination. Interestingly, sodium cyanide, potassium ferricyanide and potassium ferrocyanide at 200 microM strongly enhanced seed germination as well, whereas potassium chloride was without effect. Ferrocyanide and cyanide stimulation of seed germination was blocked by an NO scavenger. Incubation of seeds with a fluorescent NO-specific probe provided evidence for NO production in germinating switchgrass seeds. Abscisic acid (ABA) at 10 microM depressed germination, inhibited root elongation and essentially abolished coleoptile emergence. SNP partially overcame ABA effects on radicle emergence but did not overcome the effects of ABA on coleoptile elongation. Light microscopy indicated extension of the radicle and coleoptiles in seeds maintained on water or on SNP after 2 days. In contrast, there was minimal growth of the radicle and coleoptile in ABA-treated seeds even after 3-4 days. These data indicate that seed germination of warm-season grasses is significantly influenced by NO signaling pathways and document that NO could be an endogenous trigger for release from dormancy in these species.

Abscisic Acid↗

Comparison of regulatory method estimated drinking water exposure concentrations with monitoring results from surface drinking water supplies.

Crop-protection compounds are useful tools that enhance the quality of the food we enjoy. However, crop-protection products can enter aquatic systems either by direct or by indirect application. To better understand the possible frequency and magnitude of exposure to water resources, the regulatory community has developed a set of relatively straightforward models for estimating exposure to these water systems. The focus of this research was to compare how well the estimates of exposure to drinking water based on model calculations relate to actual monitoring data. Physical/chemical property data were entered in the EPA's exposure model FIRST and into PRZM/EXAMS. The predictions from FIRST and PRZM/EXAMS were then compared to actual monitoring data from a USGS/EPA cooperative program, which monitored for pesticides in vulnerable surface drinking water supplies during 1999 and 2000. Results from this examination indicate the exposure from the models can overpredict concentrations found in water by several orders of magnitude. An overprediction factor is presented that corrects model predictions to more closely approximate concentrations found in reservoirs (p = 0.05).

Environmental Exposure↗

Characterisation of sulphoxides by atmospheric pressure ionisation mass spectrometry.

An observation that a series of proprietary compounds containing a methyl thiophenyl group all underwent metabolic S-oxidation, and that the product ion spectra of the resulting S-oxides showed methyl radical loss under low-energy atmospheric pressure ionisation tandem mass spectrometry (API-MS/MS) conditions, has led to an investigation of the fragmentation of commercially available sulphoxides. The phenyl methyl sulphoxides studied do lose methyl radicals under MS/MS conditions on triple quadrupole mass spectrometers. In addition, the phenyl sulphoxides, with simple substituents other than a methyl group, also showed a tendency to lose the substituent as a radical. It was concluded that radical loss from these simple sulphoxides was characteristic of S-oxidation of these molecules. Radical losses, such as those reported here, are used in-house to distinguish S-oxidation from N- and C-oxidation in metabolism studies.

Animals↗

Evaluation of the practical feasibility and acceptability of home monitoring in residential homes.

Three residential homes to the north-west of London, with their associated medical centres, were equipped with telemonitors to measure several variables, including seven-lead electrocardiogram, blood pressure, oxygen saturation, heart rate, temperature and respiration. The monitors could be operated by non-medical personnel. After recording, the data were transmitted via the Internet to a server. A total of 24 patients with a variety of chronic conditions were monitored regularly for a period of one year. Data transmission was found to be unreliable on occasions and was improved by extending the wireless network in the homes. Data access and presentation were considered acceptable, although suggestions for minor changes were made. No discernible impact on disease management, diagnosis or care was observed as a result of the monitoring. However, interviewees saw several potential benefits and patient acceptance was very good. The monitoring was found to be generally acceptable and feasibility was considered to have been largely proven.

Aged↗

A new monitoring service for long term residential care.

eVital, a European funded project, aims to investigate the issues in the provision of vital signs monitoring services in the community. For the UK pilot, services to monitor the vital signs of patients in residential care homes by remote health care workers have been established. In particular, the aim was to allow the resident's own GP to observe the ECG, blood pressure, SpO2, temperature and respiration whilst still in the health centre and be able to advise on the most appropriate action should a crisis occur. As outcomes, this pilot project was designed to determine feasibility, channels of communication between key players and assess the technology. Trials have been under way for four months and preliminary results are promising. Residential home staff have commented on the extra level security they feel in being able to "summon" medical support for residents for whom they may have concern. Patient's relatives have also commented on the reassurance they experience from knowing that the resident is being monitored.

Aged↗

Pathologic evaluation of a spherical polyvinyl alcohol embolic agent in a porcine renal model.

PURPOSE: To evaluate the effects of a spherical embolic agent consisting of polyvinyl alcohol (PVA) and to compare this agent with commercially available embolization agents. MATERIALS AND METHODS: Eleven miniature pigs were included in the study population. The upper poles of both kidneys were selected as the target organs for embolization. PVA spheres (700-900 micro m) were used in nine kidneys, PVA particles (500-710 micro m) were used in six kidneys, gelatin spheres (700-900 micro m) were used in five kidneys, and gold-colored gelatin spheres (700-900 micro m) were used in three kidneys. Two animals were killed immediately after embolization. In the remaining animals, angiography was performed before sacrifice 7 days (in five pigs) or 28 days (in four pigs) after embolization. Pathologic and histologic evaluation of the kidneys was performed. RESULTS: All agents resulted in target vessel occlusion and end-organ infarction. All arteries embolized with spherical agents were recanalized at follow-up angiography. In vessels embolized with PVA particles, the occluding plug consisted of thrombus and PVA. In vessels embolized with spherical agents, the occluding plug consisted mostly of the embolic agent. PVA spheres were associated with the mildest inflammatory responses at 7 and 28 days when compared with PVA particles and gelatin-based microspheres. Arterial wall destruction was seen to a greater extent in kidneys embolized with gelatin-based microspheres than in those embolized with PVA-based agents. CONCLUSIONS: The spherical, PVA-based embolization agent resulted in target organ infarction and temporary arterial occlusion. The inflammatory response to PVA spheres was significantly less aggressive than the response to other agents tested. Further study with clinical and long-term pathologic follow-up is suggested to determine if these findings may have favorable clinical implications for patients undergoing embolization procedures.

Angiography↗

The effect of telemedicine on consultation time.

We have implemented an 'evidence-based referral' for primary care patients in dermatology, cardiology and peripheral vascular disease. Telemedicine clinics bring together a district nurse, patient and vascular surgeon to discuss diagnosis, management and care. During a 30-month study, a total of 30 patients participated in telemedicine clinics. The mean consultation time fell from 23 to 10 min. In parallel, the type of consultation changed from dermatology to vascular surgery. Nineteen patients participated in vascular telemedicine clinics over the last 16 months of the study. The average consultation time was 10 min (SD 1), which included discussion of the case and negotiation of its management. The average consultation time in the equivalent outpatient clinic in the same hospital for the same consultant was 15 min. The acquisition of the relevant information in primary care could lead to a reduction of 75% in outpatient clinic appointments.

Ambulatory Care Facilities↗

Percutaneous left atrial appendage occlusion (PLAATO) for preventing cardioembolism: first experience in canine model.

BACKGROUND: Atrial fibrillation is associated with a high risk for cardioembolic stroke. The left atrial appendage (LAA) is the source of the vast majority of these thromboemboli. A novel implanted device for percutaneous LAA transcatheter occlusion (PLAATO) has been designed to seal the LAA. The purpose of this study was to test the feasibility and safety of transcatheter LAA occlusion in dogs. METHODS AND RESULTS: A PLAATO implant was delivered to the LAA through a 12F transseptal catheter in 25 dogs. The PLAATO device was repositioned until occlusion was seen, or it was recaptured and replaced with a different size. LAA sealing was confirmed by intracardiac echocardiography and contrast fluoroscopy. Follow-up was performed 2 days to 6 months after implantation. After imaging assessment, dogs were euthanized and LAA was examined for device healing, migration, perforation, and any thrombosis, both grossly and histologically. The LAA was occluded in all cases. No mobile thrombi associated with the implantation were seen. Healing on the atrial-facing surface was 90% at 1 month and was complete by 3 months, which was confirmed by gross and histological examination. Light microscopic examination of brain, kidney, and spleen showed no evidence of emboli or infarct. CONCLUSIONS: Transcatheter LAA occlusion is simple and feasible. At the follow-up study, the device remained in the LAA, with benign healing and no evidence of new thrombus or damage to surrounding structures. This new strategy may provide an alternative treatment for patients with nonvalvular atrial fibrillation who are less than optimal candidates for warfarin.

Animals↗

Recent contact with health and social services by drug misusers in Glasgow who died of a fatal overdose in 1999.

AIM: To explore the recent contact with health and social services by drug misusers who died of a fatal overdose and identify opportunities for preventive intervention. DESIGN: Retrospective case analysis. SUBJECTS: Eighty-seven residents of the Greater Glasgow area who died of a drug misuse-related overdose in 1999. METHODS: Analysis of matched data from several sources: Strathclyde Police; University of Glasgow Department of Forensic Medicine and Science; the Scottish Prison Service; general practitioners' medical notes, including records of accident and emergency attendances and psychiatric assessments; and five specialist agencies for drug misusers or the homeless. FINDINGS: Most of those who died of an overdose were males, long-standing heroin injectors and resident in a deprived area. Heroin caused most deaths, either alone or with other drugs. Twenty-three per cent died within 2 weeks of release from prison. For the 77 whose medical records were available, 90% had seen their general practitioner (32% in the month before death), 48% had attended accident and emergency services and 22% had received a psychiatric assessment in the year before death. Over 40% of the 87 used a drug agency in the year before death and 20% had used more than one agency. CONCLUSIONS: Previous suicidal ideation, attempted suicide and depression were common among those who died of an overdose, as was recent release from prison. Almost all had been in contact with and several were receiving specific treatment from health or specialist addiction services in their last weeks or months. The findings highlight both the numerous opportunities for intervention and the challenge of using them to prevent death.

Adult↗

Clinical ICT systems: augmenting case management.

In order to improve the diagnosis and subsequent care given to patients, health-care workers involved in the management of their care, as well as the treatment itself, are increasingly looking at the role that information and communication technologies (ICTs) can play in supporting the complex interactions between patient, doctor or nurse, consultant and medical equipment. Effective communication both amongst health-care workers and between health-care workers and their patients in both primary and secondary care is vital; ICTs can play an important role in this. In this paper possible interpretations given to the term "telemedicine" are discussed, and then attention is turned to the challenges involved in human interaction and the role of ICTs. An example of a clinical ICT system (AIDMAN) is used to illustrate how face-to-face interaction has usefully been supported by way of a "virtual" consultation, which facilitates remote medical diagnosis and can provide improved case management.

Case Management↗

An integrated nursing and telemedicine approach to vascular care.

We have developed a telemedicine approach to vascular care for patients being managed in primary care. District nurses visit patients in their homes. Clinical information and digital photographs can be sent by email to the vascular surgeon for assessment. Where appropriate a preliminary teleconsultation between the patient and a vascular surgeon, with the nurse in attendance, is held at the primary care centre and the management of the patient is agreed. This may include referral to surgery. Over eight months six patients with diabetes and peripheral ulcers participated in the vascular telemedicine clinic. The average consultation time was 12 min (SD 4), which included discussion of the case and negotiation of its management. Important outcomes of the new system were the ability to schedule patients for rapid referral and to have completed the management of the case during the teleconsultation.

Diabetic Foot↗

Active oxygen and cell death in cereal aleurone cells.

The cereal aleurone layer is a secretory tissue whose function is regulated by gibberellic acid (GA) and abscisic acid (ABA). Aleurone cells lack functional chloroplasts, thus excluding photosynthesis as a source of active oxygen species (AOS) in cell death. Incubation of barley aleurone layers or protoplasts in GA initiated the cell death programme, but incubation in ABA delays programmed cell death (PCD). Light, especially blue and UV-A light, and H(2)O(2) accelerate PCD of GA-treated aleurone cells, but ABA-treated aleurone cells are refractory to light and H(2)O(2) and are not killed. It was shown that light elevated intracellular H(2)O(2), and that the rise in H(2)O(2) was greater in GA-treated cells compared to cells in ABA. Experiments with antioxidants show that PCD in aleurone is probably regulated by AOS. The sensitivity of GA-treated aleurone to light and H(2)O(2) is a result of lowered amounts of enzymes that metabolize AOS. mRNAs encoding catalase, ascorbate peroxidase and superoxide dismutase are all reduced during 6-18 h of incubation in GA, but these mRNAs were present in higher amounts in cells incubated in ABA. The amounts of protein and enzyme activities encoded by these mRNAs were also dramatically reduced in GA-treated cells. Aleurone cells store and metabolize neutral lipids via the glyoxylate cycle in response to GA, and glyoxysomes are one potential source of AOS in the GA-treated cells. Mitochondria are another potential source of AOS in GA-treated cells. AOS generated by these organelles bring about membrane rupture and cell death.

Abscisic Acid↗

Evolution of an open-access quantitative bioanalytical mass spectrometry service in a drug discovery environment.

Increased demand for assays for compounds at the early stages of drug discovery within the pharmaceutical industry has led to the need for open-access mass spectrometry systems for performing quantitative analysis in a variety of biological matrices. The open-access mass spectrometers described here are LC/MS/MS systems operated in 'multiple reaction monitoring' (MRM) mode to obtain the sensitivity and specificity required to quantitate low levels of pharmaceutical compounds in an excess of biological matrix. Instigation of these open-access systems has resulted in mass spectrometers becoming the detectors of choice for non-expert users, drastically reducing analytical method development time and allowing drug discovery scientists to concentrate on their core expertise of pharmacokinetics and drug metabolism. Setting up an open-access facility that effectively allows a user with minimal mass spectral knowledge to exploit the MS/MS capability of triple quadrupole mass spectrometers presents a significantly different challenge from setting up qualitative single stage mass spectrometry systems. Evolution of quantitative open access mass spectrometry within a pharmaceutical drug metabolism and pharmacokinetics group, from its beginnings as a single generic system to a series of specialist fully integrated walk-up facilities, is described.

Automation↗