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Biomedical subjects

R Graham

Publications and source records attributed to R Graham.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prospective surveillance for antibiotic-resistant organisms in patients with spinal cord injury admitted to an acute rehabilitation unit.

BACKGROUND: The objective of this study was to evaluate the epidemiology of antibiotic-resistant organisms among patients with spinal cord injury admitted to an acute rehabilitation unit for the first time. METHODS: After informed consent, 63 patients with spinal cord injury admitted to an acute rehabilitation unit between January 1997 and July 1998 had surveillance cultures (nares, urine, wounds or ulcers, and perineum) done on admission and every 2 weeks thereafter until discharge or as long as 6 weeks after admission. RESULTS: Of the 4 surveillance sites, perineal cultures most commonly grew one or more potential pathogens; however, antibiotic-resistant organisms were most often isolated from wounds or ulcers and least often in urine cultures. Staphylococcus aureus (methicillin-sensitive plus methicillin-resistant) and enterococci represented 44% of all organisms isolated in surveillance cultures. Methicillin-resistant S aureus was the most common resistant organism isolated. Less than 30% of the gram-negative bacilli isolated were considered antibiotic-resistant strains. Nosocomial infection as a result of any resistant organism was infrequent. After adjusting for various confounding factors in a logistic regression model, only the presence of a pressure ulcer predicted carriage of any resistant organism on admission to the rehabilitation unit. Acquisition of a resistant organism after admission to the unit at one or more surveillance sites occurred in 8 (22%) of 36 patients not colonized on admission. CONCLUSIONS: Methicillin-resistant S aureus was the most common resistant organism colonizing patients with spinal cord injury at the time of admission to an acute rehabilitation unit and throughout their stay. However, acquisition of any resistant organism after admission was uncommon on this unit, which used Standard Precautions in the routine care of patients. These findings have implications for the type of isolation procedures on acute rehabilitation units. The low rate of acquisition and infection with MRSA after admission argues against attempts at eradication as a method of control.

Cross Infection↗
PubMed2000

Bisphosphonates--mechanisms of action in multiple myeloma.

Bisphosphonates are a class of anti-resorptive drugs, which are effective in the treatment of osteoclast-mediated bone disease, including the osteolytic bone disease. which is a major clinical feature of patients with multiple myeloma. Recently, increases in survival following treatment with pamidronate have been observed in some patients with multiple myeloma, raising the possibility that bisphosphonates may also have an anti-tumour effect. We have demonstrated that bisphosphonates can have an anti-tumour effect in human myeloma cell in vitro, and that these anti-tumour effects induced by potent nitrogen-containing bisphosphonates are a result of inhibition of enzymes of the mevalonate pathway. However, we and others have been unable to demonstrate an anti-tumour effect of the potent bisphosphonate ibandronate in vivo, using murine models of multiple myeloma. It is therefore likely that only by studying patients receiving bisphosphonates will we be able to determine whether these compounds have a clinically important anti-tumour effect.

Animals↗
PubMed2000

Epidemiology of nosocomial infection and resistant organisms in patients admitted for the first time to an acute rehabilitation unit.

The objectives of this study were to define the epidemiology of nosocomial bacterial colonization and infection and to define predictors of nosocomial infection among a cohort (n=423) of admissions to an acute rehabilitation unit. Overall, methicillin-resistant Staphylococcus aureus (MRSA) and enterococci were the most commonly identified colonizing organisms. Escherichia coli and Pseudomonas aeruginosa were the most commonly identified colonizing gram-negative bacilli. During 70 (16.5%) of the 423 hospitalizations in the unit, 94 nosocomial infections occurred. The most common infections were those of the urinary tract (30% of 94 infections) or a surgical site (17%), Clostridium difficile diarrhea (15%), and bloodstream infection (12.8%). Antibiotic-resistant bacteria most commonly caused bloodstream infection (41.7%) and surgical site infection (56.3%). Independent predictors of nosocomial infection at the time of admission were functional status (measured with the functional independence measure), APACHE III score, and spinal cord injury. In conclusion, gram-positive organisms were the predominant strains causing nosocomial colonization and infection. The logistic model, if verified, may be useful in defining patients who should be targeted for measures to prevent nosocomial infection.

APACHE↗
PubMed2000

Fluid resuscitation of patients with multiple injuries and severe closed head injury: experience with an aggressive fluid resuscitation strategy.

BACKGROUND: Despite increasing experimental and clinical evidence to the contrary, a dichotomy of management strategies of the patient with multiple injuries still exists, based on the presence or absence of traumatic brain injury. Many still advocate fluid restriction or small volume resuscitation if traumatic brain injury is present. PURPOSE: To demonstrate results of aggressive fluid resuscitation in a prospective case series of patients with multiple injuries and with severe head injury. METHODS: Thirty-four patients with Glasgow Coma Scale score < or = 8 and Injury Severity Score > or = 16 were enrolled into the study over a period of 18 months. Fluid resuscitation was guided in part by cerebral perfusion pressures (mean cerebral perfusion pressures > 80) as well as by hemodynamic monitoring and evidence of end organ perfusion. Overall fluid intake, intensive care unit fluid balance, presence or absence of hypoxia, hypotension, or both, were analyzed. Ninety- and 180-day Glasgow Outcome Scale and Disability Rating Scale scores were also obtained. RESULTS: By using an aggressive fluid resuscitation strategy, secondary insults were avoided in 74% of the patients. A good functional outcome was achieved in 74% and mortality was impressively low at 6%. CONCLUSION: Fluid restriction is not necessary to achieve good results in the severely injured patient who also has a severe head injury.

Adolescent↗
PubMed1999

Expression of B7.1 in a MUC1-expressing mouse mammary epithelial tumour cell line inhibits tumorigenicity but does not induce autoimmunity in MUC1 transgenic mice.

The MUC1 epithelial mucin, which is overexpressed and aberrantly glycosylated in breast and other carcinomas, is also expressed on the apical surface of most normal glandular epithelial cells. Since clinical trials evaluating the efficacy of MUC1-based vaccines have been initiated in breast cancer patients, it is important to address the question of whether an effective immune response to the cancer associated mucin can be generated without inducing autoimmunity. Since non-classic cytotoxic T lymphocyte (CTL) responses to MUC1 have been reported, it is also relevant to examine the role of costimulatory molecules in the effective presentation of MUC1 based antigens. We have therefore looked at the effect of expressing B7.1 on the tumorigenicity of a MUC1 expressing mammary epithelial cell line (410.4) in a transgenic mouse expressing MUC1 on its normal glandular epithelial tissues. Coexpression of B7.1 with MUC1 in 410. 4 cells resulted in a dramatic inhibition of tumour growth which depended on the activity of CD4+ and CD8+ T cells. The epithelial tissues in the transgenic mice able to reject the B7.1, MUC1-expressing tumours showed no evidence of degeneration and the mice survived their normal life span. The results demonstrate that an immune response to the MUC1 antigen can be induced in MUC1 transgenic mice and that presentation of the antigen, whether directly or by cross-priming, is markedly enhanced by coexpression of B7.1.

Animals↗
PubMed1999

Use of auditory icons as emergency warnings: evaluation within a vehicle collision avoidance application.

In the context of emergency warnings, auditory icons, which convey information about system events by analogy with everyday events, have the potential to be understood more quickly and easily than abstract sounds. To test this proposal, an experiment was carried out to evaluate the use of auditory icons for an in-vehicle collision avoidance application. Two icons, the sounds of a car horn and of skidding tyres, were compared with two conventional warnings, a simple tone and a voice saying 'ahead'. Participants sat in an experimental vehicle with a road scene projected ahead, and they were required to brake in response to on-screen collision situations and their accompanying warning sounds. The auditory icons produced significantly faster reaction times than the conventional warnings, but suffered from more inappropriate responses, where drivers reacted with a brake press to a non-collision situation. The findings are explained relative to the perceived urgency and inherent meaning of each sound. It is argued that optimal warnings could be achieved by adjusting certain sound attributes of auditory icons, as part of a structured, user-centred design and evaluation procedure.

Accidents, Traffic↗
PubMed1999

Impairment of driving performance caused by sleep deprivation or alcohol: a comparative study.

A study was conducted to assess the relative impact of partial sleep deprivation (restriction to 4 h sleep before testing) and full sleep deprivation (no sleep on the night before testing) on 2 h of simulated driving, compared with an alcohol treatment (mean blood alcohol content = 0.07%). Data were collected from the 64 male participants on the primary driving task, psychophysiology (0.1 Hz heart rate variability), and subjective self-assessment. The results revealed that the full sleep deprivation and alcohol group exhibited a safety-critical decline in lane-keeping performance. The partial sleep deprivation group exhibited only noncritical alterations in primary task performance. Both sleep-deprived groups were characterized by subjective discomfort and an awareness of reduced performance capability. These subjective symptoms were not perceived by the alcohol group. The findings are discussed with reference to the development of systems for the online diagnosis of driver fatigue. Potential applications of this research include the formulation of performance criteria to be encompassed within a driver impairment monitoring system.

Adult↗
PubMed1999

Entry of US medical school graduates into family practice residencies: 1998-1999 and 3-year summary.

This is the 18th report prepared by the American Academy of Family Physicians (AAFP) on the percentage of each US medical school's graduates entering family practice residency programs. Approximately 15.4% of the 16,114 graduates of US medical schools between July 1997 and June 1998 were first-year family practice-residents in October 1998, compared with 16.6% in 1997 and 15.9% in 1996. Medical school graduates from publicly funded medical schools were almost twice as likely to be first-year family practice residents in October 1998 than were residents from privately funded schools, 18.8% compared with 10.7%. The Mountain region reported the highest percentage of medical school graduates who were first-year residents in family practice programs in October 1998 at 22.0%; the Middle Atlantic and New England regions reported the lowest percentages at 9.9% and 8.7%, respectively. Half of the medical school graduates (50.0%) entering a family practice residency program as first-year residents in October 1998 entered a program in the same state where they graduated from medical school. The percentages for each medical school have varied substantially from year to year since the AAFP began reporting this information. This article reports the average percentage for each medical school for the last 3 years. Also reported are the number and percentage of graduates from colleges of osteopathic medicine who entered Accreditation Council for Graduate Medical Education-accredited family practice residency programs, based on estimates provided by the American Association of Colleges of Osteopathic Medicine.

Family Practice↗
PubMed1999

Results of the 1999 National Resident Matching Program: family practice.

The 1999 National Resident Matching Program (NRMP) results reflect continued volatility in the perceptions and career choices of physicians entering graduate medical education in the United States. A total of 117 fewer positions (155 fewer US seniors) were filled in family practice residency programs in 1999, as well as 23 fewer (29 fewer US seniors) in primary care internal medicine and 38 fewer (27 fewer US seniors) in internal medicine-pediatric programs. In contrast, nine more positions (19 more US seniors) were filled in anesthesiology and one more (10 more US seniors) in diagnostic radiology, two "marker" disciplines that have recently been market sensitive. Seventy-three more positions (but 67 fewer US seniors) were also filled in categorical internal medicine, while 30 more positions (40 more US seniors) were filled in categorical pediatrics programs, where trainees are "pluripotential" with perceived options for practicing as generalists or entering subspecialty fellowships, depending on the market. While the demands of managed care and the needs of rural and underserved populations continue to offer a market for family physicians, family practice experienced a second year of "primary care backlash" through the 1999 NRMP. In addition, current forces appear to be influencing some students to choose subspecialty rather than primary care careers.

Career Choice↗
PubMed1999

Retroperitoneoscopic surgery is not associated with increased carbon dioxide absorption.

PURPOSE: Previous studies have suggested that retroperitoneal laparoscopy is associated with greater carbon dioxide absorption and related postoperative morbidity, such as subcutaneous emphysema and pneumothorax. We prospectively compared the effects of carbon dioxide absorption during transperitoneal and retroperitoneal laparoscopic renal and adrenal surgery at our institution. MATERIALS AND METHODS: Data were collected prospectively on 51 patients who underwent laparoscopic renal (26) or adrenal (25) surgery via the transperitoneal (18) or retroperitoneal (33) approach from September 1997 to February 1998. RESULTS: There was no significant difference in carbon dioxide elimination in patients who underwent transperitoneal laparoscopy compared to retroperitoneoscopy at any interval. Subcutaneous emphysema occurred in 12.5% of the transperitoneal and 45% of the retroperitoneal group (p = 0.09). Patients with subcutaneous emphysema had greater carbon dioxide elimination during the first 2.5 hours of insufflation compared to those without subcutaneous emphysema and, thereafter, carbon dioxide elimination decreased to baseline. CONCLUSIONS: In contrast to previous reports our prospective nonrandomized study suggests that retroperitoneoscopy is not associated with greater carbon dioxide absorption compared to transperitoneal laparoscopy. Patients with subcutaneous emphysema exhibited only transient increases in carbon dioxide absorption above control levels.

Absorption↗
PubMed1999

An investigation of hypomagnesemia among ambulatory urban African Americans.

BACKGROUND: Magnesium represents the fourth most abundant cation in the body and plays an integral role in intracellular metabolism. Although magnesium deficiency states have been associated with a variety of medical conditions, the prevalence of hypomagnesemia has not been well studied, particularly in ambulatory settings. METHODS: We performed a period prevalence study using 120 patients seen for routine medical care at an urban family medicine center. Chart reviews were completed for these subjects. We used univariate and multivariate analyses to correlate magnesium levels with demographic and clinical factors. RESULTS: There was a 20% overall prevalence of hypomagnesemia among this predominantly female, African American population. The prevalence of hypomagnesemia was greatest among patients with a history of alcoholism (odds ratio [OR] = 6.00; 95% confidence interval [CI], 1.41-26.1) and among those having 1 or more of the following medical conditions: diabetes, hyperlipidemia, hypertension, renal disease, and asthma (OR = 4.69; 95% CI, 1.37-17.65). CONCLUSIONS: The prevalence of hypomagnesemia among patients from this urban minority community exceeds that reported in previous studies of the general population. This may be reflective of greater comorbidity, diminished nutritional status, or poorer overall health among patients from this community. The association between hyperlipidemia and magnesium deficiency warrants further investigation.

Adult↗
PubMed1999

Increased efficiency and cost-effectiveness in the evaluation of the blunt abdominal trauma patient with the use of ultrasound.

The efficacy and effectiveness of ultrasound (US) in evaluating patients suspected of having blunt abdominal trauma are near that of computed tomography (CT) and diagnostic peritoneal lavage (DPL). Because no cost-effectiveness study has been reported, the purpose of this study was to demonstrate that US is more efficient and cost-effective than CT/DPL in evaluating blunt abdominal trauma. Over a 9-month period, 331 patients suspected of sustaining blunt abdominal trauma were evaluated at a Level I trauma center by US, CT, and/or DPL. Cost data and time to disposition were determined for analysis. The sensitivity, specificity, and accuracy of US were similar to those reported in previous studies. There was a significant difference in time to disposition with the US group being significantly lower (P = 0.001). The total procedural cost was 2.8 times greater for the CT/DPL group than for the US group. US is not only effective in diagnosing blunt abdominal trauma, but it is also more efficient and cost-effective than is CT/DPL.

Abdominal Injuries↗
PubMed1998

Factors determining outcome for breast-conserving irradiation with margin-directed dose escalation to the tumor bed.

PURPOSE: A prospectively applied treatment policy for breast-conserving therapy used margin assessment as the exclusive guide to the intensity of therapy directed at the tumor-bearing quadrant. METHODS AND MATERIALS: From 1982-1994, there were 509 treated Stage I and II breast carcinomas with a median follow-up of 72 months. For operational purposes, tumor excision margins were prospectively defined as: > 5 mm, 2.1-5 mm, > 0 < or = 2 mm, and positive. If a margin was assessed as < or = 2 mm or indeterminate, and it was deemed cosmetically feasible, a reexcision of the tumor bed would be performed. All patients received whole breast irradiation to 50-50.4 Gy. The following scheme for tumor bed boost irradiation as a function of final margin status (FMS) was observed: (a) Minimal risk = no tumor found on reexcision, no boost performed; (b) low risk = FMS > 5 mm, boost of 10 Gy; intermediate risk = FMS 2.1-5 mm, boost to 14 Gy; high risk = FMS < or = 2 mm or positive, boost to 20 Gy. Cases were analyzed for local failure (LF) with respect to histology (invasive ductal (IDC), IDC with associated DCIS (IDC/DCIS), invasive lobular (ILC)), age, tumor size, total excision volume, reexcision, total dose, tamoxifen therapy, and chemotherapy. RESULTS: There were 19 breast recurrences for a Kaplan-Meier local failure rate for all cases at 5 and 10 years of 2.7% and 7.1%, respectively. Local failure in the first 4 years of follow-up was rare, with a mean annual incidence rate of 0.25% that rose to a mean of 1.1% in subsequent years. Univariate results of Cox proportional hazards regression survival models found positive FMS (p = 0.02), IDC/DCIS (p = 0.04) and age (0.0006) as significantly associated with local failure. In a multivariable model of FMS and IDC/DCIS, FMS retained significance (p = 0.01) but IDC/DCIS was borderline (p = 0.06). When FMS and age were included in a multivariable model, there was a significant interaction (p = 0.01) between the two variables. There was a significant increase in the relative risk of LF for age < or = 45 years (range 11.1-17.4), irrespective of FMS category. Although excellent overall control rates were achieved for patients > 45 years, for younger patients LF rates appeared to remain proportional to the relative closeness of the FMS, despite rigorous dose escalation. CONCLUSIONS: Graded tumor-bed dose escalation in response to FMS results in an exceptionally low risk of "early" local recurrence within the first 5 years of follow-up. However, this strategy is unable to completely overcome the longer term adverse influence of young age and positive FMS.

Adult↗