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Biomedical subjects

M Harper

Publications and source records attributed to M Harper.

At least 19 recordsLinked to original sources
PubMed2002

Intratesticular lipoma.

Benign intratesticular lesions are rare. We describe the second reported case of an intratesticular lipoma and discuss the limitations of ultrasonography in differentiating benign from malignant conditions occurring within the testis.

Humans↗
PubMed2002

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.

Drinking↗
PubMed2002

Targeting the kinesin Eg5 to monitor siRNA transfection in mammalian cells.

RNA interference, the inhibition of gene expression by double-stranded RNA, provides a powerful tool for functional studies once the sequence of a gene is known. In most mammalian cells, only short molecules can be used because long ones induce the interferon pathway. With the identification of a proper target sequence, the penetration of the oligonucleotides constitutes the most serious limitation in the application of this technique. Here we show that a small interfering RNA (siRNA) targeting the mRNA of the kinesin Eg5 induces a rapid mitotic arrest and provides a convenient assay for the optimization of siRNA transfection. Thus, dose responses can be established for different transfection techniques, highlighting the great differences in response to transfection techniques of various cell types. We report that the calcium phosphate precipitation technique can be an efficient and cost-effective alternative to Oligofectamine in some adherent cells, while electroporation can be efficient for some cells growing in suspension such as hematopoietic cells and some adherent cells. Significantly, the optimal parameters for the electroporation of siRNA differ from those for plasmids, allowing the use of milder conditions that induce less cell toxicity. In summary, a single siRNA leading to an easily assayed phenotype can be used to monitor the transfection of siRNA into any type of proliferating cells of both human and murine origin.

Calcium Phosphates↗
PubMed2001

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.

Anti-Bacterial Agents↗
PubMed2001

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.

Adult↗
PubMed2000

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.

Adsorption↗
PubMed2000

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.

Air Pollution↗
PubMed2000

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.

Age Factors↗
PubMed2000

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.

Coroners and Medical Examiners↗
PubMed2000

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.

Antineoplastic Agents, Phytogenic↗
PubMed1999

A prospective randomized trial evaluating tissue effects of finasteride therapy in benign prostatic hyperplasia.

Finasteride is widely used for the treatment of benign prostatic hyperplasia (BPH). Its therapeutic efficacy is believed to be mediated through selective inhibition of prostatic 5alpha-reductase (type II). This prospective, controlled, randomized study examines various relationships between changes in tissue 5alpha-reductase isozyme activity, epithelial proliferative index and morphology in men with BPH treated with finasteride for 6 months, and correlates these with clinical response. Thirty-one patients presenting with symptomatic bladder outflow obstruction were prospectively randomized to receive either finasteride or placebo (2:1) for 24 weeks. Of these, 27 men aged 55-80 y (median 69 y) completed the study, including 18 patients on treatment. Symptom score determination, uroflow and prostate volume were assessed at baseline and end of study. Prostatic tissue was obtained by ultrasound-guided needle biopsy at baseline and by transurethral resection (TURP) at end of study for biochemical and morphometric analysis. Epithelial proliferation was examined quantitatively in the resected tissue using MIB-1 antibody to Ki-67 and counting the percentage of positively staining cells. Type II 5alpha-reductase activity was strongly inhibited by finasteride in resected BPH tissue, with over 100-fold decrease in V(max) (P=0.001), whereas the type I isozyme was inhibited 5-fold (P=0.005). Selective inhibition of type II 5alpha-reductase was demonstrated in all treated patients. No significant difference in epithelial proliferation was observed between the finasteride and placebo groups. Epithelial proliferation was, however, greater in prostatic tissue with histological manifestation of inflammation (2.02% vs 0.89%, P=0.001). Positive correlation between the total epithelial volume and the ratio of transition zone volume/total prostate volume was observed in the placebo group (r=0.834), whereas there was no such correlation in men taking finasteride (r=-0.300), consistent with a reduction in epithelial content in the treatment group. Improvement in uroflow and reduction in prostatic volume in patients treated with finasteride did not reach statistical significance. This study shows that finasteride causes inhibition of 5alpha-reductase activity in human BPH tissue with selectivity for the type II isozyme. In spite of this, no significant effects in epithelial proliferation or tissue morphology were demonstrated. The presence of inflammation was, however, associated with significantly greater proliferative activity. The power of this study was limited by the small number of recruited patients, and a larger study would be required for further investigation of morphological changes induced by finasteride in BPH tissue and their biochemical basis.

Journal Article↗