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Biomedical subjects

R Sage

Publications and source records attributed to R Sage.

At least 19 recordsLinked to original sources

Groundwater abstraction pollution risk assessment.

A generic groundwater pollution risk assessment methodology has been developed to enable the evaluation and ranking of the potential risk of pollution to groundwater abstractions. The ranking can then be used to prioritise risk management or mitigation procedures in a robust and quantifiable framework and thus inform business investment decisions. The risk assessment consider the three components of the pollution transport model: source-pathway-receptor. For groundwater abstractions these correspond to land use (with associated pollutants and shallow subsurface characteristics), aquifer and the abstraction borehole. An hierarchical approach was chosen to allow the risk assessment to be successfully carried out with different quality data for different parts of the model. The 400-day groundwater protection zone defines the catchment boundary that form the spatial limit of the land use audit for each receptor. A risk score is obtained for each land use (potential pollution source) within the catchment. These scores are derived by considering the characteristics (such as load, persistence and toxicity) of all pollutants pertaining to each land use, their on-site management and the potential for the unsaturated subsurface to attenuate their effects in the event of a release. Risk scores are also applied to the aquifer characteristics (as pollutant pathway) and to the abstraction borehole (as pollutant receptor). Each risk score is accompanied by an uncertainty score which provides a guide to the confidence in the data used to compile the risk assessment. The application of the methodology has highlighted a number of problems in this type of work and results of initial case studies are being used to trial alternative scoring methods and a more simplified approach to accelerate the process of pollution risk assessment.

Models, Theoretical↗

Supporting primary and secondary pupils with communication and behaviour problems.

Numerous studies have identified communication skills as being most predictive of long-term school success. A Communication Opportunity Group Scheme (COGS) took place in a primary and secondary school involving 36 students aged 7-15 years. There were 24 subjects in two types of teaching group and 12 controls. One group was taught for an hour a week over ten weeks (weekly) and the other for two hours daily over five days (intensive) by teachers trained in the COGS method. Experimental groups showed significant gains compared with controls. Integrating systematic teaching of communication into the curriculum may significantly increase pupil performance. The project has fostered a learning community of schools, support services, national charities and the university.

Adolescent↗

Off-loading neuropathic wounds associated with diabetes using an ankle-foot orthosis.

Patients with chronic diabetes have a broad spectrum of associated peripheral neurologic deficits that culminate in an increased susceptibility to ulcer formation. The authors focus on the use of the ankle-foot orthosis as both a treatment and a definitive solution for achieving ulcer closure and for minimizing the chance of ulcer recurrence in the ambulatory patient. An analysis of the pathologic forces encountered, and the solution achieved with the ankle-foot orthosis is presented. In addition, the results from a clinical pilot study in subjects with recalcitrant ulcers secondary to Charcot's neuroarthropathy are presented.

Ankle↗

Benchmark analysis on diabetics at high risk for lower extremity amputation.

After the 1990 establishment of a multidisciplinary foot salvage clinic, 1346 diabetic patients, at high risk for the development of foot ulcers and eventual lower limb amputation, were followed for 4 years. Of the 224 high-risk patients admitted to the hospital, 74 amputations (5.5%) of all or part of a lower limb were performed. Patients undergoing amputation were younger, more severely ill, and required more frequent hospitalizations because of greater organ system involvement. They were also more likely to be institutionalized after discharge. Overall, patients with long-standing adult-onset diabetes, identified as at high risk for foot ulcer development, have a substantially increased risk for lower limb amputation, multiple organ system failure, hospitalization, and institutionalization than do diabetic patients as a whole. Clinical benchmarking facilitates the identification and reduction of unnecessary variations in patient care practices. Here, a formal benchmark analysis provides the current outcome expectations for amputation rates and co-morbidities in patients with diabetes who are classified as at high risk for lower extremity amputation. Management of these patients in a structured, multidisciplinary foot salvage clinic, augmentation of baseline services, and preliminary benchmark data may provide a standard for the measurement of therapeutic interventions that improve patient care.

Adult↗

Amputations in the diabetic foot.

Foot amputation in the diabetic population can help maintain a patient's independent ambulation and function. Such surgery requires diligence of the surgeon and a watchful eye for the development of early and long-term complications. Careful adherence to the listed healing parameters can assist the surgeon in achieving healing rates of above 90%.

Amputation, Surgical↗

Methicillin resistant Staphylococcus aureus in three adjacent health districts of south-east England 1986-91.

The experiences with methicillin-resistant Staphylococcus aureus (MRSA) of two contiguous Health Districts during 1986-91 and of a third mutually adjacent District in south-east England during 1989-91 were compared. Although the three Districts were in many ways similar, the nature of the problems posed by MRSA differed. The Districts had dealt with MRSA independently but had evolved similar strategies for coping with the organism. In two Districts a gradual relaxation of case-finding and of infection control precautions applied to individual patients and outbreaks, was followed by a reduction in the number of new patient-isolates identified from routine bacteriology specimens. Standardization of MRSA isolation rates for patient throughput and for length of hospital stay showed the examination of crude total isolates to provide misleading comparisons of relative risks of acquiring MRSA in different specialties. It was also found that patients discharged from specialties with short inpatient stays were more likely to have MRSA detected after discharge by their physicians working in the local community served by the hospitals but there was no evidence of spread outside hospital. It is suggested that good all-round standards of infection control practice are more important than specific radical policies in dealing with endemic MRSA.

Colony Count, Microbial↗

A treatment algorithm for neuropathic (Charcot) midfoot deformity.

Forty-nine feet in 47 patients with midfoot neuropathic foot deformity were referred for care to a comprehensive foot salvage clinic and followed for an average of 3.6 years. Twenty-three initially presented without open ulcers. Two underwent elective Syme's ankle disarticulation amputation, and the others were kept ambulatory with a combination of periods of nonweightbearing cast immobilization, accommodative extra-depth shoes with custom orthotics, and ankle-foot orthoses. Twenty-six of the feet initially presented for care with open ulcers and/or chronic osteomyelitis. Twenty-two of these patients underwent 32 surgical procedures. Sixteen underwent debridement of the infected bone and surrounding soft tissues. Excision of large, nonaccommodative boney prominence, termed exostectomy, was performed in eight. Partial excision of the deformed midfoot combined with boney stabilization and attempted arthrodesis, termed partial tarsectomy, were performed in seven. All surgical patients were managed postoperatively with long-term custom accommodative bracing. Follow-up at an average of 3.6 years revealed that all but one of the patients remained ambulatory. Six walk with accommodative shoe gear and persistent stable chronic open ulcers. None required below-knee amputation. Five amputations were performed, three at the Syme's ankle disarticulation level, one at the Chopart's hind-foot level, and one at the mid-foot level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Transcutaneous oxygen tension in the dysvascular foot with infection.

Eight adult insulin-requiring diabetics with peripheral vascular disease were admitted with foot infection and signs of systemic sepsis. Transcutaneous oxygen tension was measured at the foot and ankle prior to surgery. None of the values were sufficient to support wound healing. Four of the patients underwent open ray resection and four open midfoot amputation. After resolution of the local infections, transcutaneous oxygen tensions were repeated. Seven of the eight patients exhibited an appreciable increase in the value following decompression of the foot infection, sufficient to support wound healing.

Adult↗

Amputations in the diabetic foot and ankle.

Scientific structured foot salvage clinics will provide surgeons with a large population of peripheral vascular insufficiency patients who may someday become candidates for salvage amputation at the foot or ankle level. This article presents the technology of functional amputation levels.

Amputation, Surgical↗

Transcutaneous oxygen as a predictor of wound healing in amputations of the foot and ankle.

Thirty-eight amputations of the foot and ankle were performed in patients with peripheral vascular insufficiency over a 20-month period. Amputation level selection was based on clinical examination, a minimum ankle-brachial index of 0.5 as a measure of vascular supply, serum albumin of 3.0 gm/dl as a measure of tissue nutrition, and a total lymphocyte count of 1500 as a measure of immunocompetence. Transcutaneous oxygen tension was measured at the midfoot and ankle levels prior to surgery. Thirty-two of 38 patients (84.2%) healed their amputation wounds. When the transcutaneous oxygen tension was greater than 30 mm Hg, 24 of 26 patients (92.3%) healed. When the value was below 30 mm Hg, only eight of 12 patients healed. When the propensity to support wound healing is factored out, with patients having the metabolic capacity to heal an amputation wound in the foot and ankle, it appears that transcutaneous oxygen tension is an accurate measure of vascular inflow to support amputation wound healing.

Adult↗

Syme's two-stage amputation in insulin-requiring diabetics with gangrene of the forefoot.

Thirty-five insulin-requiring adult diabetic patients underwent 38 Syme's Two-Stage amputations for gangrene of the forefoot with nonreconstructible peripheral vascular insufficiency. All had a minimum Doppler ischemic index of 0.5, serum albumin of 3.0 gm/dl, and total lymphocyte count of 1500. Thirty-one (81.6%) eventually healed and were uneventfully fit with a prosthesis. Regional anesthesia was used in all of the patients, with 22 spinal and 16 ankle block anesthetics. Twenty-seven (71%) returned to their preamputation level of ambulatory function. Six (16%) had major, and fifteen (39%) minor complications following the first stage surgery. The results of this study support the use of the Syme's Two-Stage amputation in adult diabetic patients with gangrene of the forefoot requiring amputation.

Adult↗

Prospective study of amikacin versus netilmicin in the treatment of severe infection in hospitalized patients.

PURPOSE: Four previous studies comparing netilmicin and amikacin have yielded inconclusive results concerning efficacy and rates of nephrotoxicity and ototoxicity. For this reason, we conducted a prospective, randomized, controlled trial of the two drugs in the treatment of hospitalized patients with severe infection. PATIENTS AND METHODS: A total of 202 patients were enrolled in the study; 100 received netilmicin and 102 received amikacin. Concomitant antimicrobials were restricted to metronidazole and benzylpenicillin. Peak and trough aminoglycoside levels were assayed within the first 36 hours and at least every 72 hours thereafter. A full blood cell count, serum electrolytes, creatinine, bilirubin, and liver enzymes were measured before therapy, weekly thereafter, and within 48 hours after the discontinuation of therapy. Nephrotoxicity and ototoxicity were assessed in patients. A standard agar dilution procedure was used to determine minimal inhibitory concentrations. RESULTS: No significant pretreatment differences were found between the two groups. Patients in the amikacin group responded significantly better to treatment than did patients in the netilmicin group (90% versus 79%; p less than 0.05). A notable finding was the markedly inferior response rate of Pseudomonas aeruginosa infections to netilmicin as compared with amikacin (13 of 24 with a favorable response compared with 25 of 26). No significant difference in ototoxicity was found, whereas nephrotoxicity appeared to be significantly less with amikacin (4% versus 12%, p less than 0.05). Although amikacin seemed less nephrotoxic than netilmicin, this may have been related to the significantly greater number of patients with initial renal dysfunction who received netilmicin. CONCLUSIONS: Amikacin appears to be significantly more efficacious than netilmicin for the treatment of P. aeruginosa infections, especially those in non-urinary tract sites. There is no apparent difference between the two drugs in terms of ototoxicity.

Acute Disease↗

Complications following midfoot amputation in neuropathic and dysvascular feet.

A review of 64 midfoot amputations performed between 1980 and 1985 revealed that complications occurred in 42% of the series. These included early wound dehiscence and late re-ulceration after the patient began walking again. By providing aggressive management and appropriate local revisions, 84% of the original group's limbs were salvaged at a functionally significant level. These findings underscore the fact that midfoot amputation requires diligent immediate and long-term follow-up if an acceptable success rate is to be achieved.

Amputation, Surgical↗

A randomized trial of empirical antibiotic therapy with one of four beta-lactam antibiotics in combination with netilmicin in febrile neutropenic patients.

Over a two year period 174 evaluable episodes of fever in neutropenic patients were treated in a randomized study comparing four beta-lactam antibiotics, each given in combination with netilmicin. Exclusions included episodes due to viral or fungal infection, and trial violations. Most patients were receiving treatment for leukaemia, including 18% undergoing bone marrow transplantation. The overall response rate (EORTC criteria) was 66%, ranging from 56% for cefoperazone to 76% for mezlocillin. Microbial documentation was obtained in 31% of episodes; Gram-positive isolates were most frequent but Pseudomonas aeruginosa was found in 18 patients. In patients with microbiologically documented infection 70% improved, overall--from 40% with cefoperazone to 80% with piperacillin (P less than 0.05). Nephrotoxicity was seen in 6.7% and was associated with severe documented sepsis. Hypokalaemia was seen in 29% and was most marked in patients receiving ticarcillin. Rashes occurred in 6.6% overall, with no difference between the groups. Ototoxicity, shown by serial audiograms, was seen in 4.7% of patients. No evidence of vestibular dysfunction was seen in 62 patients studied. Of thirteen deaths due to the primary infection, seven were caused by Ps. aeruginosa and five by fungi.

Agranulocytosis↗

Novel method for purification of staphylococcal enterotoxin A.

A novel single-step procedure for the purification of staphylococcal enterotoxin A (SEA), namely, dye ligand affinity chromatography with the triazine dye Red A, was developed. SEA purified by this method produced a single band when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The yield from 5 liters of culture supernatant was 0.113 g, corresponding to an overall yield of 55%. In some instances, purification of SEA from culture supernatants by dye ligand affinity chromatography produced two enterotoxin peaks that could be eluted from the column with 300 and 500 mM phosphate buffer (pH 6.8). Enterotoxin from these peaks produced a single band when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but multiple bands were observed on isoelectric focusing gels. This method of purification represents a significant improvement in time, yields, and purity of enterotoxin over previously published purification methods.

Chromatography, Affinity↗