Biomedical subjects
M Harper
Publications and source records attributed to M Harper.
Bladder and renal stones: management and treatment.
The prevalence of renal tract calculi in the population is such that patients may present acutely not only to urologists, but in the setting of any medical specialty. This article aims to enable all practitioners to be able to recognize the condition and instigate early investigation and management before referring to the urologist for definitive treatment.
Financial and clinical impact of false-positive blood culture results.
During a 4-year period, 9465 specimens for blood culture were obtained from 11,911 highly febrile, otherwise healthy young children. Of these specimens, 87 (0.9%) yielded nonpathogens and were considered to be false-positive blood culture results (FPBCRs). Seventy-two of the patients who provided these specimens were treated on an outpatient basis (resulting in $10,821 in treatment charges), and 7 were admitted to the hospital (resulting in $16,200 in charges) as a result of the FPBCRs. Studies performed during follow-up included a second blood culture (21 patients), complete blood cell count (11), urine analysis and culture (5), lumbar puncture (3), and chest radiography (3). Only a small minority of patients were hospitalized or underwent invasive procedures. The charges associated with FPBCRs are very small in comparison to the initial charges of culturing specimens obtained from children considered to be at risk. Concern about the consequences of FPBCRs should not deter clinicians from performing indicated cultures for children who potentially have bacteremia.
Prenatal diagnosis of complete sole trisomy 1q.
The prenatal diagnosis of a complete trisomy of the long arm of chromosome 1 is reported. Major ultrasound findings included: nuchal thickening, bi-temporal narrowing, a single choroid plexus cyst, and mild ventriculomegaly. There was a mass in the chest and abdomen, pleural effusion, ascites and a hyperechoic bowel. Skin edema was present. The fetus died at 26 weeks' gestation. A literature review is presented of 17 de novo and two inherited cases with only trisomy 1q. Of note is the fact that 3/5 prenatally detected 1q trisomies have teratomas. A review of the literature reveals a dismal outcome for trisomy 1q cases if the duplication involves bands 1q25-->q32.
Performance evaluation of on-site colorimetric air sampling techniques.
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Haematuria: a streamlined approach to management.
Haematuria can often herald significant underlying pathology. This article highlights the potential causes of haematuria and suggests a management algorithm.
Sorbent trapping of volatile organic compounds from air.
The use of sorbents in trapping volatile organic compounds in air for subsequent analysis is reviewed. Sorbents are classified in accordance with the mechanism used to recover the trapped compounds, either solvent or thermal desorption. The use of sorbents is contrasted with other sampling procedures, such as collecting whole air samples using canisters. New developments such as solid-phase microextraction are described. In particular, emphasis is placed on a holistic approach to sampling and analysis, and communication is encouraged between those who take samples in the field, and those who perform the analysis.
Nonstress tests versus biophysical profiles.
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Validation of parachlorobenzotrifluoride, benzotrifluoride, and monochlorotoluene on diffusive samplers.
Three solvents (OXSOL 10, monochlorotoluene or mixed isomers of 1- chloro-2-methyl benzene and 1-chloro-4-methyl benzene; OXSOL 100, parachlorobenzotrifluoride or 1-chloro-4-(trifluoromethyl) benzene; and OXSOL 2000, benzotrifluoride or trifluoromethyl benzene) produced by Occidental Chemical Corporation (Niagara Falls, NY) were considered as candidates for SKC, Inc.'s on-going diffusive sampler validation program. The 575-series diffusive sampler contains coconut-shell charcoal (575-001) or Anasorb 747 (575-002). Both samplers were used in this study. Desorption efficiency was tested at loadings equivalent to eight-hour time-weighted average (TWA) exposures to 0.01-2 times the Occidental Chemical Corporation in-house limit values (respectively: 50 ppm, 25 ppm, and 100 ppm,. All results met the National Institute for Occupational Safety and Health (NIOSH) criteria of > 75 percent, and, except for the lower loadings of parachlorobenzotrifluoride, the results were in the range of 90-110 percent. The calculated uptake rates were verified for different periods of exposure, up to eight hours, and found to be within 5 percent of the calculated for all three compounds on both samplers. A detailed comparison of the results from different time periods indicated no significant reverse diffusion effects for any combination of sampler and analyte. Samplers exposed to standard atmospheres of each compound were stored for three weeks at ambient temperatures and reanalyzed with results between 94 and 107 percent of expected. Based on full validation of samplers for the lower homologue (benzene), the bi-level theory of sample validation as endorsed by international validation protocols establishes this as a complete validation of the featured samplers for sampling vapors of these chemicals in air.
Predictors of bacteremia in febrile children 3 to 36 months of age.
PURPOSE: To develop an improved model for the prediction of bacteremia in young febrile children. METHODS: A retrospective review was performed on patients 3 to 36 months of age seen in a children's hospital emergency department between December 1995 and September 1997 who had a complete blood count and blood culture ordered as part of their regular care. Exclusion criteria included current use of antibiotics or any immunodeficient state. Clinical and laboratory parameters reviewed included age, gender, race, weight, temperature, presence of focal bacterial infection, white blood cell count (WBC), polymorphonuclear cell count (PMN), band count, and absolute neutrophil count (ANC). Logistic regression analyses were used to identify factors associated with bacteremia, defined as growth of a pathogen in a blood culture. The model that was developed was then validated on a second dataset consisting of febrile patients 3 to 36 months of age collected from a second children's hospital (validation set). RESULTS: There were 633 patients in the derivation set (46 bacteremic) and 9465 patients in the validation set (149 bacteremic). The mean age of patients in the derivation and validation sets were 15.8 months (95% confidence interval [CI]: 15.2-16.5) and 16.6 months (95% CI: 16.5-16.8), respectively; the mean temperatures were 39.1 degrees C (95% CI: 39. 0-39.2) and 39.8 degrees C (95% CI: 39.7-39.8); 56% were male in the derivation set and 55% male in the validation set. Predictors of bacteremia identified by logistic regression included ANC, WBC, PMN, temperature, and gender. Receiver operator characteristic (ROC) analysis showed similar performance of ANC and WBC as predictors of bacteremia. When placed into a multivariate logistic regression model, band count was not significantly associated with bacteremia. Information regarding focal infection was available for 572 patients in the derivation set. The percentage of patients diagnosed with bacteremia with a focal bacterial infection was not significantly different from the percentage who had bacteremia without a focal bacterial infection (16/200 vs 30/372). Based on this dataset, a logistic regression formula was developed that could be used to develop a unique risk value for each patient based on temperature, gender, and ANC. When the final model was applied to the validation set, the area under the ROC curve (AUC) constructed from these data indicated that the model retained good predictive value (AUC for the derivation vs validation data =.8348 vs 0.8221, respectively). CONCLUSIONS: Use of the formulas derived here allows the clinician to estimate a child's risk for bacteremia based on temperature, ANC, and gender. This approach offers a useful alternative to predictions based on fever and WBC alone.bacteremia, detection, white blood cell.
Rapid, high-yield method for the bulk purification of fibronectin from human plasma.
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The multidisciplinary approach to dealing with families: a model for medical examiners.
Medical examiners function primarily to determine cause and manner of death, and to document illness and injuries. Equally important, however, is the role of providing family members with the initial tools to work through the grief process. By initiating contact with the family, facilitating access to other appropriate services and by making provisions for adequate viewing and meeting facilities, we fulfill these ethical duties and carry out our responsibilities as physicians. We hope to fill some of the void that exists in the forensic medical literature with this presentation and generate awareness for the neglected role of grief intervention.
Irinotecan in the management of patients with pancreatic cancer.
Synergy with no overlapping toxicities has been demonstrated for the combination of irinotecan (Camptosar, CPT-11) and gemcitabine (Gemzar) in vitro. Results of a single-institution phase I study in which patients with previously untreated pancreatic cancer were given irinotecan and gemcitabine were promising, with two of three patients achieving a partial response. Because of the favorable outcome of the phase I study, a multicenter phase II trial was undertaken in previously untreated patients with pancreatic carcinoma. Data from other sites entering patients in this phase II study have been analyzed, and a multicenter phase III trial of single-agent gemcitabine vs the irinotecan combination in first-line treatment of patients with locally advanced or metastatic pancreatic cancer is underway.
Management of penetrating injury to the petrous internal carotid artery: case report.
We report the management of a penetrating foreign body injury to the neck with a length of fencing wire traversing the internal carotid artery within the petrous temporal bone and entering the middle cranial fossa. Discussion points include methods of haemorrhage control, as well as ligation versus repair or bypass as the definitive treatment.
Non-typhi Salmonella bacteremia in children.
BACKGROUND: Non-typhi Salmonella (NTS) infections are a frequent cause of self-limited diarrheal illness in healthy children. Bacteremia is a known complication of NTS infection, but the management of children with bacteremia has been based on limited data. OBJECTIVE: To study the outcomes of pediatric patients with NTS bacteremia. METHODS: Retrospective review of patients with NTS bacteremia covering a 16-year period at an urban pediatric hospital. Clinical data from the initial visits and any follow-up visits or hospitalizations were abstracted from the medical record. RESULTS: We studied 144 patients. Median age was 10.5 months. Fifty-four patients were hospitalized at the initial visit including all the patients with immunodeficiency (n = 12). Of the 90 patients initially managed as outpatients, 79 were subsequently admitted; only 1 of these patients developed a focal complication. Persistent bacteremia was found in 51 (41%) patients. Among nonimmunocompromised patients, persistent bacteremia was noted in 34% [95% confidence interval (CI), 20 to 52%] of those initially treated with oral antibiotics, 52% (CI 30 to 74%) of those initially treated with a parenteral dose of antibiotics and in 31% (CI 22 to 43%) of those who were not initially given antibiotics. No laboratory or clinical factors predicted persistent bacteremia. Twelve patients developed focal infections: 3 of 119 previously healthy children (2.5%, CI 0.5 to 7%); and 9 of 25 children with underlying medical conditions (36%, CI 19 to 57%). Focal infections included meningitis (3), osteomyelitis (4), septic arthritis (2), pneumonia (2) and cholangitis (1). CONCLUSIONS: NTS bacteremia occurs in otherwise healthy children, although the risk of focal infections is small. Patients with NTS bacteremia frequently have persistent bacteremia at follow-up regardless of initial antibiotic treatment.
Expression of the mitotic motor protein Eg5 in postmitotic neurons: implications for neuronal development.
It is well established that the microtubules of the mitotic spindle are organized by a variety of motor proteins, and it appears that the same motors or closely related variants organize microtubules in the postmitotic neuron. Specifically, cytoplasmic dynein and the kinesin-related motor known as CHO1/MKLP1 are used within the mitotic spindle, and recent studies suggest that they are also essential for the establishment of the axonal and dendritic microtubule arrays of the neuron. Other motors are required to tightly regulate microtubule behaviors in the mitotic spindle, and it is attractive to speculate that these motors might also help to regulate microtubule behaviors in the neuron. Here we show that a homolog of the mitotic kinesin-related motor known as Eg5 continues to be expressed in rodent neurons well after their terminal mitotic division. In neurons, Eg5 is directly associated with the microtubule array and is enriched within the distal regions of developing processes. This distal enrichment is transient, and typically lost after a process has been clearly defined as an axon or a dendrite. Strong expression can resume later in development, and if so, the protein concentrates within newly forming sprouts at the distal tips of dendrites. We suggest that Eg5 generates forces that help to regulate microtubule behaviors within the distal tips of developing axons and dendrites.
Acceptability to patients of a home hospital.
OBJECTIVE: To examine the acceptability to older patients of receiving care in the home for acute medical conditions that require hospital level care by current standards. DESIGN: Interviews with patients during hospitalization regarding their views of a hypothetical "home hospital." PARTICIPANTS: Patients (n = 87) admitted to a community-based academic medical center with a primary diagnosis of pneumonia, congestive heart failure, or chronic obstructive airway disease, their nurses (n = 111), and resident physicians (67). MEASUREMENTS: A questionnaire was developed to measure several domains of acceptability and expectations for care. RESULTS: A majority of patients agreed that treatment in a home hospital would be more comfortable compared with treatment in a hospital (78.5%), would be less likely to result in an infection (62.5%), and would not be a burden to their family (71.8%). There was less certainty that medical care at home can be as good as in the hospital (56.9%). Nearly three-quarters (72.3%) of patients would choose home hospital if it were available. CONCLUSION: Patients may be ready to accept home hospital as an alternative for acute care. The acceptability of home hospital to acutely ill older patients is a critical factor in the development of this alternative for care and has the potential for improving satisfaction with care, reducing complications, hastening return to function, and, possibly, of lowering costs of care.
Long-term reduction in asthma morbidity following an asthma self-management programme.
The adult "credit card" asthma self-management plan has been shown to be an effective and acceptable system for reducing asthma morbidity when introduced as part of a 6 month community-based asthma programme. The aim of the present study was to assess the effectiveness of the credit card plan 2 yrs after the end of the programme. Markers of asthma morbidity and use of medical services were compared during the 12 months before enrolment, and 2 yrs after completing the 6 month asthma programme. Of the 69 participants who originally enroled in the 6 month asthma programme, 58 were surveyed 2 yrs after completion of the programme. These participants showed a significant improvement in all but one of the asthma morbidity measures. The proportion waking most nights with asthma in the previous 12 months decreased from 29 to 9% (p=0.02), emergency visits to a general practitioner decreased from 43 to 16% (p=0.001), hospital emergency department visits with asthma decreased from 19 to 5% (p=0.02) and hospital admissions decreased from 17 to 5% (p=0.04). Only 24% of patients reported that they usually monitored their peak flow rate daily, but this increased to 73% during a "bad" attack of asthma. A long-term reduction in asthma morbidity and requirement for acute medical services can result following the introduction of the adult credit card asthma self-management plan. Adult patients with asthma are most likely to undertake peak flow monitoring preferentially during periods of unstable asthma, rather than routinely during periods of good control.