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Biomedical subjects

S E Martin

Publications and source records attributed to S E Martin.

At least 37 records · Page 2Linked to original sources
PubMed1999

Maximum acceptable forces of dynamic pushing: comparison of two techniques.

The purpose of this experiment was to investigate maximum acceptable initial and sustained forces while performing a push of 7.6 m, performed at a frequency of 1 push min-1 on a magnetic particle brake treadmill and a high-inertia push-cart. Eight male industrial workers performed a 40 min treadmill pushing task in the context of a larger experiment and two, 2 h push-cart tasks with a unique water loading system. A psychophysical methodology was employed, whereby the subjects were asked to select a workload they could sustain for 8 h without straining themselves or without becoming unusually tired, weakened, overheated or out of breath. The results revealed that maximum acceptable initial and sustained forces of pushing on the high inertia cart were significantly higher (28 and 23%, respectively) than pushing forces on the magnetic particle brake treadmill. It was concluded that adjustments to the pushing and pulling data bank by Snook and Ciriello (1991) may be appropriate if verification of this experiment yields similar results.

Adult↗
PubMed1999

Use of the laryngeal mask airway in air transport when intubation fails.

BACKGROUND: A prospective, nonrandomized cohort study was conducted to determine the effectiveness of the laryngeal mask airway (LMA) for management of the difficult airway in patients requiring air transport. METHODS: The LMA was inserted in those patients who could not be successfully intubated. Data were collected to evaluate the effectiveness of the LMA and to document any complications attributed to its use. RESULTS: Inclusion criteria were met in 17 of the 25 patients receiving an LMA. The device was inserted successfully in 16 of 17 of the patients (94%). In-flight oxygen saturation ranged from 97 to 100%, and end-tidal carbon dioxide ranged from 24 to 35 mm Hg. At arrival, initial arterial blood gas values indicated adequate oxygenation in all patients and adequate ventilation in 15 of 16 patients (94%). There was no evidence of complications. CONCLUSION: Our patient data show that when conventional methods have failed, the LMA can be safely, rapidly, and effectively used for temporary airway control.

Adolescent↗
PubMed1999

Effects of iron and selenium on the production of catalase, superoxide dismutase, and listeriolysin O in Listeria monocytogenes.

Listeria monocytogenes 19112, Scott A, and 10403S were grown in tryptic soy broth (TSB) and TSB supplemented with 25 to 100 microg/ml of iron (Fe) and 0.5 to 2.5 microg/ml selenium (Se) to examine the effects on catalase (CA), superoxide dismutase (SOD), and listeriolysin O (LLO) activities. Growth in TSB supplemented with Fe resulted in significant increases in CA, SOD, and LLO activities in all three strains when compared to growth in TSB. The addition of 0.5 microg/ml Se to TSB resulted in significantly higher CA and LLO activities in L. monocytogenes 19112 but showed no effect on Scott A or 10403S. These results suggest that Fe plays a role in increasing the activities of CA, SOD, and LLO.

Bacterial Toxins↗
PubMed1998

Psammoma bodies in fine-needle aspirates of the thyroid: predictive value for papillary carcinoma.

BACKGROUND: Although characteristic of thyroid papillary carcinoma, psammoma bodies occasionally arise in benign or nonpapillary lesions. Their predictive value in fine-needle aspirates (FNA), without other features suggestive of papillary carcinoma, is uncertain. METHODS: This retrospective study determined the frequency of psammoma bodies and other calcifications in 313 FNAs and 69 resected thyroids; positive predictive value, sensitivity, and specificity were calculated and compared with a triad of characteristic cytologic features (papillary fronds, nuclear ridges/grooves, and intranuclear inclusions). Psammoma bodies from benign and malignant conditions were assessed for differentiating architectural or staining characteristics. RESULTS: Psammoma bodies were found in only 8 of 313 FNAs. Their positive predictive value for papillary carcinoma was 50%, the rest arising from multinodular goiters. By contrast, the positive predictive value of combined cytologic features was 100%. These features were also much more sensitive, present in 80% of papillary carcinomas compared with 14% with psammoma bodies. The psammoma bodies of papillary carcinoma could not be differentiated from those of other lesions either by staining characteristics or by architecture. Other types of calcifications also were present in diverse conditions, and did not discriminate among them. CONCLUSIONS: Isolated psammoma bodies are an unreliable predictor of papillary carcinoma in the absence of cytologic features. In view of the relatively low aggressiveness of papillary carcinoma in most age groups, repeat fine-needle aspiration and clinical correlation are recommended prior to consideration of surgery.

Biopsy, Needle↗
PubMed1998

Detection of ovarian cancer cells: comparison of a telomerase assay and cytologic examination.

BACKGROUND: Telomerase is an enzyme essential for the normal replication of chromosomes. Telomerase activity is absent in most somatic cells in adults, but it is usually expressed in cancer cells, including ovarian carcinoma cells. Our principal goal was to compare the sensitivity of a telomerase assay, i.e., the telomeric repeat amplification protocol (TRAP) assay, with that of cytologic examination in detecting cancer cells in the peritoneal cavity of patients with ovarian carcinoma. METHODS: TRAP assays and cytologic examinations were performed on peritoneal washings and ascitic fluids from 42 patients with active ovarian carcinoma. Control specimens included washings from 29 patients with benign ovarian diseases and ascitic fluids from 14 patients with liver failure. We also evaluated the stability of telomerase in ascitic fluids left unprocessed at room temperature as well as the ability of the TRAP assay to detect cancer cells in mixtures containing large numbers of normal cells. RESULTS: Specimens from 37 (88%) of the 42 patients with ovarian carcinoma tested positive for telomerase. Cytologic examination detected cancer cells in only 27 of the telomerase-positive specimens (i.e., in specimens from 64% of the 42 patients). This difference of 24% (95% confidence interval = 17%-30%) in sensitivity between the two tests was statistically significant (two-sided P = .002). Specimens from five of the patients with ovarian carcinoma were cytologically negative and telomerase negative. All 43 control specimens were cytologically negative, but the TRAP assay detected telomerase in two of them. Telomerase activity was detected in unprocessed samples left at room temperature for 5 days and in mixtures containing a small number of cancer cells and a 2000- to 10000-fold excess of normal cells. CONCLUSIONS: Assaying for telomerase is more sensitive than cytologic examination in detecting cancer cells in the peritoneal cavity of patients with ovarian carcinoma.

Ascitic Fluid↗
PubMed1998

Cytologic features of mycobacterial pleuritis: logistic regression and statistical analysis of a blinded, case-controlled study.

Tuberculous pleural effusions are characterized by lymphocytosis; the significance of mesothelial cells is uncertain, as are the cytologic features in concurrent human immunodeficiency virus (HIV) infection. This blinded study compared 38 culture-positive pleural fluids (6 HIV+) with 38 controls from benign exudative processes. Logistic regression analysis selected mature lymphocytes as most predictive of positive culture, and mesothelial cells and eosinophils as negative predictors. Mesothelial cells were scant (< 10% of nucleated cells) in 36/38 cases with mycobacteria (sensitivity 95%); if these cell were > 10%, tuberculosis was virtually ruled out in HIV- patients. Specificity was maximized (82%) when mesothelial cells < 10% were combined with lymphocytes > 50%; positive predictive value with this combination was 76%, but was raised to 96% if moderate/marked cellularity was also identified. Among tuberculosis cases, reactive mesothelial cells differentiated HIV+ from HIV- patients; there was no other significant difference.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Fine needle aspiration (FNA) in HIV+ patients: results from a series of 655 aspirates.

There are many selected small series or case reports of FNAs in patients with HIV infection, but large series are rare and epidemic's characteristics have evolved over time. The current study, from a large public hospital in the USA, included women as well as men, hetero- and homosexuals, in-patients and out-patients, and deep radiologically guided aspirates as well as superficial masses. Of 655 FNAs, reactive or benign changes were present in 37% confirmed or suspected malignancy in 13%, specific infection with stainable organisms in 14%, and inflammation in 16%. Twenty percent of cases were inadequate for diagnosis. Most of the identifiable infections were associated with Mycobacterium tuberculosis, with fewer atypical mycobacteria, fungi and other bacteria. Clinically significant diagnoses were correlated with deep aspirate location and lesion size > 2 cm, confirming other studies which also identified tenderness and recent enlargement as important indicators. The liberal use of FNA in our HIV+ population has greatly reduced the necessity for surgical nodal resection, reassured clinicians in continuing observation of reactive lymphadenopathy, and allowed immediate therapy for specific infection, cyst or malignancy.

AIDS-Related Opportunistic Infections↗
PubMed1998

Video based lifting technique coding system.

Despite automation and improved working conditions, many materials in industry are still handled manually. Among the basic activities involved in manual materials handling, lifting is the one most frequently associated with low-back pain (LBP). Biomechanical analysis techniques have been used to better understand the risk factors associated with manual handling, but because these techniques require specialized equipment, highly trained personnel, and interfere with normal business operations, they are limited in their usefulness. A video based lifting technique analysis system (the VidLiTeCTM System) is presented that provides for quantifiable non-invasive biomechanical analysis of the dynamic features of lifting with high inter-coder reliability and low sensitivity to absolute errors. Analysis of results from a laboratory experiment and from field-collected videotape are described that support the reliability, sensitivity, and accuracy claims of the VidLiTeCTM System. The VidLiTeCTM System allows technicians with minimal training and low-tech equipment (a camcorder) to collect large sets of lifting data without interfering with normal business operations. A reasonably accurate estimate of the peak compressive force on the L5/S1 joint can be made from the data collected. Such a system can be used to collect quantified data on lifting techniques that can be related to LBP reporting.

Biomechanical Phenomena↗
PubMed1998

Randomised placebo controlled trial of daytime function after continuous positive airway pressure (CPAP) therapy for the sleep apnoea/hypopnoea syndrome.

BACKGROUND: Patients with the sleep apnoea/hypopnoea syndrome (SAHS) report improved sleepiness, cognitive function, and psychological well being after continuous positive airway pressure (CPAP) therapy, and it is for these daytime features that CPAP is usually given. However, few randomised or controlled studies exist on the effects of CPAP on daytime function. METHODS: A prospective, randomised, single blind, placebo controlled, crossover trial of daytime function after CPAP was conducted in 23 patients with SAHS, all with > or = 15 apnoeas + hypopnoeas/hour and > or = 2 symptoms of SAHS. All patients spent four weeks on CPAP therapy and four weeks on oral placebo treatment, following randomisation to treatment order. With ethics committee approval, patients were told the placebo tablet might improve upper airway function. Average effective CPAP use was monitored using hidden time clocks. Assessments of objective and subjective sleepiness, symptoms, cognitive performance, and psychological well being were performed on the last day of each treatment and compared. RESULTS: Objective sleepiness measured by sleep onset latency on the multiple sleep latency test improved with CPAP (mean difference from placebo +2.4 min, 95% CI 0.8 to 4.0; p < 0.001) as did subjective sleepiness on the Epworth scale (mean difference -6, 95% CI -3 to -9; p = 0.001). Symptom total score also fell with CPAP (mean difference -1.6, 95% CI -2.2 to -1.0; p < 0.001). No determinants of these changes with active treatment were identified, and no significant enhancements to cognitive function or psychosocial well being were found in this small sample. CONCLUSIONS: These findings provide further evidence for clinically significant benefits to daytime function from CPAP.

Adult↗
PubMed1998

Heat stability of virulence-associated enzymes from Listeria monocytogenes SLCC 5764.

The enzyme activities of listeriolysin O (LLO), phosphatidylinositol-specific phospholipase C (PI-PLC), catalase (CA), and superoxide dismutase (SOD) from Listeria monocytogenes SLCC 5764 were examined after heat treatment, growth at elevated temperatures, and anaerobic growth. Growth at elevated temperatures may influence virulence as expressed by virulence enzyme activity. The enzymes were heated for 0 and 10 min at temperatures ranging from 40 to 100 degrees C. The production of LLO was examined when the bacterium was grown at elevated temperatures, and the production of LLO, CA, and SOD were examined after anaerobic growth. LLO was the most heat-labile factor, losing almost all activity when heated above 50 degrees C. CA was more heat stable, showing no decrease in activity until it was heated at 55 degrees C. The PI-PLC enzyme was most heat resistant: the activity decreased between 40 and 50 degrees C and continued to decrease when heated between 65 and 100 degrees C. When L. monocytogenes was grown at elevated temperatures, it produced less LLO than when grown at the optimum growth temperature of 37 degrees C. When the organism was grown under anaerobic conditions, the levels of CA and LLO decreased, while the SOD level remained unchanged.

Bacterial Toxins↗
PubMed1997

Detection of hyperdiploid malignant cells in body cavity effusions by fluoresence in situ hybridization on ThinPrep slides.

BACKGROUND: Benign body cavity effusions sometimes cannot be distinguished from malignant ones by conventional cytology. The authors performed fluorescence in situ hybridization (FISH) on ThinPrep slides using chromosome specific probes to see if hyperdiploid malignant cells could be detected in 20 body cavity effusions. The results were then compared with those of conventional cytology. METHODS: A total of 20 body cavity effusions from 19 patients were studied using conventional cytology and FISH. Probes specific for chromosomes 3, 8, 10, and 12 were used to detect hyperdiploidy on ThinPrep slides (Cytyc Corporation, Boxborough, MA). RESULTS: A total of 13 patients had malignant conditions (either prior history of malignancy or the presence of malignancy anywhere in the body). Conventional cytology and FISH were both positive in 5 of these patients (6 samples) and negative in 2 patients. The results for one sample were inconclusive by both methods. There were 5 discrepant cytology-FISH results in patients with malignant conditions. One sample was positive by FISH and negative by cytology, one was positive by FISH and "atypical" by cytology, and three were inconclusive by FISH and negative by cytology. FISH results were either negative (in 4 samples) or inconclusive (in 2 samples) in the 6 patients with benign conditions. CONCLUSIONS: FISH can detect hyperdiploid malignant cells in body cavity effusions and is especially useful when the major cell population consists of malignant cells that cannot be differentiated from mesothelial or "atypical" cells. It is less useful in detecting a small population of malignant cells hidden in an inflammatory or reactive cell background. More studies are needed to establish diagnostic criteria further and to assess the clinical usefulness of this procedure.

Adult↗
PubMed1997

Core needle biopsy. A useful adjunct to fine-needle aspiration in select patients with palpable breast lesions.

BACKGROUND: Fine-needle aspiration (FNA) biopsy is an established, highly accurate method for diagnosing palpable breast lesions. However, in some cases a definitive diagnosis cannot be made by FNA alone, either due to the inherent limitations of cytology itself or the ability to obtain adequate material for diagnosis. This study evaluated the usefulness of a supplemental core needle biopsy performed by a cytopathologist in conjunction with an FNA biopsy in select patients. METHODS: Twelve patients with palpable breast lesions underwent the combined FNA/core needle biopsy procedure during the study period from March 1995 through March 1996. All 12 patients first had an FNA aspiration that was preliminarily evaluated by the FNA cytopathologist while the patient was at the clinic. If the cytopathologist was unable to render a definitive diagnosis of the lesion type or if a repeat FNA was requested by the clinician because of a previous non-definitive FNA result, a core needle biopsy was then performed. RESULTS: When the FNA and the core needle biopsies were reviewed together, a correct definitive diagnosis was made in 10 of the 12 cases. In contrast, review of the FNA material alone yielded a correct definitive diagnosis in only five cases. CONCLUSIONS: The supplemental core needle biopsy was found to be especially useful in: 1) providing a definitive diagnosis of infiltrating carcinoma in those cases in which the FNA diagnosis was reported as "suspicious;" 2) providing ample tissue for ancillary studies; and 3) differentiating a phyllodes tumor from a fibroadenoma. It is the authors' opinion that the FNA cytopathologist is the physician best qualified to perform the combined FNA/core needle biopsy procedure should he/she deem it necessary.

Biopsy, Needle↗
PubMed1997

Local anesthesia for fine-needle aspiration biopsy of palpable breast masses: the effectiveness of a jet injection system.

To determine the effectiveness of the Biojector 2000 needle-free lidocaine injection system in achieving satisfactory local anesthesia for fine-needle aspiration (FNA) of palpable breast lesions, we studied 29 female patients. Each patient served as her own control and had two FNA biopsies performed on the lesion. The first FNA biopsy was preceded by either no anesthesia, ethyl chloride cold spray, or traditional needle lidocaine injection. The second FNA was preceded by the Biojector 2000. Twenty-four patients (83%) reported that they preferred the Biojector 2000 over either no anesthesia, ethyl chloride spray, or needle and syringe lidocaine injection. The Biojector 2000 needle-free injection system is an effective and useful method of local anesthesia for FNA of palpable breast masses.

Adult↗
PubMed1997

The relationship of alcohol to injury in assault cases.

Little is known about the precise role of alcohol in the escalation of interactions from threats into physical violence or its contribution to the risk of injury. Experimental studies indicate that intoxicated subjects (allegedly) give markedly higher electric shocks than sober subjects and are less sensitive to their cries of pain. However, few studies in a naturalistic setting have examined whether aggressive acts become more serious and result in higher injury rates when the assailants have been drinking than when they are sober. This chapter reviews the two bodies of research on the effects of alcohol on interpersonal aggression and violence; presents new data on the escalation of threatening interactions to assaults and the likelihood of victim injury given an assault, using data from the National Crime Victimization Survey for the years 1992 and 1993; and suggests future directions for research based on our findings that alcohol's impact on both escalation and injury differed according to the victim-assailant relationship.

Adolescent↗
PubMed1997

Complex chromosome 4, 9, and 22 rearrangement in a patient presenting with AML-FAB M2.

Fluorescence in situ hybridization (FISH) and the reverse transcription-polymerase chain reaction (RT-PCR) were used to examine a patient presenting with acute myelogenous leukemia (AML) FAB M2, and a complex t(4;9;22)(p14;q34;q11.2). The patient's clinical course was characterized by an aggressive leukemia, resistant to intensive therapy including allogeneic bone marrow transplantation. FISH analysis, using two chromosome painting probes and a BCR/ABL specific probe, confirmed the cytogenetic observation of a 22q11.2-->4p14 and a 4p14-->9q34 exchange, and revealed the presence of a 9q34-->22q11.2, respectively. In addition, RT-PCR demonstrated the presence of a BCR/ABL transcript derived from the major breakpoint cluster region (M-bcr) of the BCR gene. This transcript has been shown to generate an active 210 kDa tyrosine kinase protein more commonly observed in chronic myelogenous leukemia. Because the presentation of AML with this ABL-->BCR fusion product is a rare event, it would seem likely that the additional complex chromosomal rearrangement involving chromosomes 4, 9, and 22 played a role in the aggressive presentation and clinical behavior of this patient's leukemia.

Adult↗
PubMed1997

Fine-needle aspiration of peripheral lymph nodes in patients with tuberculosis and HIV.

Previous studies of fine-needle aspiration (FNA) specimens from lymph nodes of patients with tuberculosis (TB) and infection with the human immunodeficiency virus (HIV) have often involved small numbers of specimens and have produced conflicting results. We reviewed 93 FNA specimens from peripheral lymph nodes in a consecutive series of 79 patients with TB to compare results for patients with and without HIV infection. The 45 patients with HIV infection in the series were more frequently male, more likely to have negative results on a purified protein derivative tuberculin skin test, and they had more disseminated disease. Granulomatous inflammation, a positive result on a culture, acid-fast bacilli, or necrosis was found in 71% of the studies. Identification of granulomatous inflammation occurred at a similar rate in FNA specimens from patients with HIV infection (16%) and without HIV infection (21%; P = .56). Necrosis was the sole reported finding in a significant subset of cases (16%), occurring in patients with and patients without HIV infection. FNA of peripheral lymph nodes of patients with TB was an effective diagnostic test. Granulomatous inflammation and other FNA findings in peripheral lymph nodes of patients with TB were similar in those with and those without HIV infection.

Adult↗