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Biomedical subjects

K Freeman

Publications and source records attributed to K Freeman.

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

The baryon halo of the milky way: A fossil record of its formation

Astronomers believe that the baryon (stellar) halo of the Milky Way retains a fossil imprint of how it was formed. But a vast literature shows that the struggle to interpret the observations within a consistent framework continues. The evidence indicates that the halo has built up through a process of accretion and merging over billions of years, which is still going on at a low level. Future satellite missions to derive three-dimensional space motions and heavy element (metal) abundances for a billion stars will disentangle the existing web and elucidate how galaxies like our own came into existence.

Journal Article↗
PubMed2000

Real-time transmission of full-motion echocardiography over a high-speed data network: impact of data rate and network quality of service.

UNLABELLED: With high-resolution network transmission required for telemedicine, education, and guided-image acquisition, the impact of errors and transmission rates on image quality needs evaluation. METHODS: We transmitted clinical echocardiograms from 2 National Aeronautics and Space Administration (NASA) research centers with the use of Motion Picture Expert Group-2 (MPEG-2) encoding and asynchronous transmission mode (ATM) network protocol over the NASA Research and Education Network. Data rates and network quality (cell losses [CLR], errors [CER], and delay variability [CVD]) were altered and image quality was judged. RESULTS: At speeds of 3 to 5 megabits per second (Mbps), digital images were superior to those on videotape; at 2 Mbps, images were equivalent. Increasing CLR caused occasional, brief pauses. Extreme CER and CDV increases still yielded high-quality images. CONCLUSIONS: Real-time echocardiographic acquisition, guidance, and transmission is feasible with the use of MPEG-2 and ATM with broadcast quality seen above 3 Mbps, even with severe network quality degradation. These techniques can be applied to telemedicine and used for planned echocardiography aboard the International Space Station.

Artifacts↗
PubMed2000

Impact of a design modification in modern firefighting uniforms on burn prevention outcomes in New York City firefighters.

Our aim was to determine the impact of three different firefighting uniforms (traditional, modern, and modified modern) on the incidence and severity of thermal burn injuries, the major occupational injury affecting firefighters. Injury data were collected prospectively for the entire New York City Fire Department (FDNY) firefighting force wearing FDNY's traditional uniform (protective over-coat) from May 1, 1993 to August 31, 1993; FDNY's modern uniform (protective over-coat and over-pant) from May 1, 1995 to August 31, 1995; and FDNY's modified modern uniform (short sleeved shirt and short pants, rather than long-sleeved shirt and long pants, worn under firefighter's protective over-clothes) from May 1, 1998 to August 31, 1998. Outcome measures were burn incidence and severity. Adverse outcomes were heat exhaustion and cardiac events. During this 12-month study, 29,094 structural fires occurred. The incidence rate for upper extremity burns was 2341 per 100,000 fires and for lower extremity burns, 2076 per 100,000 fires. With the change from the traditional to modern uniform, the distribution of burns per fire decreased significantly (P = 0.001) for upper extremity burns (86%) and lower extremity burns (93%). With the change from traditional to modern uniform, days lost to medical leave for upper or lower extremity burns decreased by 89%. The majority of burns occurred at the lower arm and mid-leg, and the change to the modern uniform decreased such burns by 87% and 92%. Burn incidence and severity were not significantly affected by the change to the modified modern uniform. The distribution of heat exhaustion or cardiac events per fire was not significantly affected by the change from the traditional to modern uniform, and heat exhaustion was decreased (P < 0.001) by the change to the modified modern uniform. In conclusion, the modern uniform dramatically reduced burn incidence and severity without adverse impact. The modified modern uniform significantly reduced heat exhaustion without significantly affecting thermal protection.

Adult↗
PubMed2000

Issues in families of children with brain tumors.

PURPOSE/OBJECTIVES: To determine the needs of children with brain tumors and their parents/guardians and siblings during the six stages of illness: diagnosis, hospitalization, posthospitalization, adjuvant treatment, recurrence, and terminal or reported cured. DESIGN: A cross-sectional, qualitative study of families using focus group methodology. SETTING/SAMPLE: Families with a child diagnosed with a brain tumor recruited from the practices and clinics of several major teaching hospitals in the New York metropolitan area. Families traveled as far as 70 miles for the group meeting. Varying ethnic groups and family structures were represented. METHODS: Groups were separated into parents/guardians, siblings, and affected children. The children's groups were divided further into age 10 and older and younger than age 10. During the focus group, moderators followed an outline of topics identified from family interviews, the literature, and content experts that were important to families in similar situations. An assistant moderator took detailed notes, and the entire group meeting was audiotaped. Information was transcribed and analyzed using qualitative analysis techniques. FINDINGS: 11 focus groups met involving 7 affected children, 24 adults, and 19 siblings. Issues identified as important by the group members fell into four categories: Interaction With Healthcare Providers, Medical Information/Education, Healthcare Utilization and Treatment, and Psychosocial Issues. The needs of family members differed at various stages of the illness. CONCLUSIONS: The particular impact of the four major areas of concern differed by family role and stage of illness. IMPLICATIONS FOR NURSING PRACTICE: To provide optimal care, healthcare professionals must be aware of the family's composition and support systems and the impact that the illness has on individual family members at each stage of illness.

Adaptation, Psychological↗
PubMed2000

The Dunn light.

Explore the source record for details and available documents.

Dental Equipment↗
PubMed1999

Isotope selection for patients undergoing prostate brachytherapy.

PURPOSE: Ultrasound-guided transperineal interstitial permanent prostate brachytherapy (TIPPB) is generally performed with either 103Pd or 125I. The use of 125I for low Gleason score tumors and 103Pd for higher Gleason scores has been suggested based on isotope dose rate and cell doubling time observed in in vitro studies. While many centers follow these isotope selection criteria, other centers have elected to use only a single isotope, regardless of Gleason score. No clinical data have been published comparing these isotopes. This study was undertaken to compare outcomes between 125I and 103Pd in a matched pair analysis for patients undergoing prostate brachytherapy. METHODS AND MATERIALS: Six hundred forty-eight consecutively treated patients with clinically confined prostate cancer underwent TIPPB between June 1992 and February 1997. Five hundred thirty-two patients underwent TIPPB alone, whereas 116 received pelvic external beam irradiation and TIPPB. Ninety-three patients received androgen deprivation therapy prior to TIPPB. The prescribed doses for TIPPB were 160 Gy for 125I (pre-TG43) and 120 Gy for 103Pd. Patients treated with combination therapy received 41.4 or 45 Gy (1.8 Gy/fraction) external beam irradiation followed by a 3- to 5-week break and then received either a 120-Gy 125I or a 90-Gy 103Pd implant. Until November 1994, all patients underwent an 125I implant after which the isotope selection was based on either Gleason score (Gleason score 2-5:125I; Gleason 5-8:103Pd) or isotope availability. A matched pair analysis was performed to assess any difference between isotopes. Two hundred twenty-two patients were matched according to Gleason score, prostate-specific antigen (PSA), and stage. PSA relapse-free survival (PSA-RFS) was calculated based on the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Group definition of failure. Kaplan-Meier actuarial survival curves were compared to assess differences in pretreatment PSA and Gleason score. RESULTS: Univariate analysis of the 648 patients identified Gleason score, pretreatment PSA value, and stage as significant factors to predict PSA-RFS, but failed to identify isotope selection as significant. To address the significance of isotope selection further, the matched pair groupings were performed. The minimum follow-up for all 222 matched patients is 24 months with a median follow-up of 42 months (24-82). The actuarial PSA-RFS at 5 years for all 222 patients is 86.5%. One hundred eleven of the 222 matched patients received a 103Pd implant with an 87.1% 5-year PSA-RFS. The remaining 111 patients underwent a 125I implant with an 85.9% 5-year PSA-RFS (p = n.s.). Analysis of Gleason score subgroups 2-4, 5-6, and 7-9 failed to show any significant difference in PSA-RFS comparing isotopes. Pretreatment PSA subgroups of < or = 10 or > 10 ng/ml also failed to show any significant difference in PSA-RFS survival comparing isotopes. Analysis of postimplant dosimetry using dose delivered to 90% of the prostate volume (D90) did not identify any difference between the isotope groups. CONCLUSIONS: This matched pair analysis failed to demonstrate a difference for 125I and 103Pd in PSA-RFS for patients undergoing TIPPB. In addition, there were no observed advantages for either 125I or 103Pd in either the low or high Gleason score groups. This data indicates that the role of isotope selection for patients undergoing TIPPB requires further clarification.

Analysis of Variance↗
PubMed1999

Prevalence of peripheral neuropathy in injection drug users.

BACKGROUND: Nucleoside analogue reverse transcriptase inhibitors are a critical component of antiretroviral therapy in HIV-infected persons. Several of these medications cause painful, dose-limiting peripheral neuropathy (PN), which may develop earlier and more intensely in persons with preexisting neuropathy. The prevalence of baseline peripheral neuropathy in injection drug users (IDUs), one of the largest populations of HIV-infected persons, has not been described, yet has important implications for the selection of antiretroviral therapy. METHODS: The authors performed a cross-sectional study of PN in 212 HIV-seronegative and HIV-seropositive IDUs using detailed neurologic histories, physical examinations, quantitative electrophysiologic study, and quantitative sensory testing. Data were used to assign patients to one of four positive categories of PN or one of two negative categories. RESULTS: PN was present in 24.5% of HIV-seronegative IDUs, three to four times the reported frequency for HIV-seronegative persons in the general or male homosexual population. PN was present in 32.1% of HIV-seropositive patients. PN was axonal in nature and associated with increased age and alcohol use. PN was asymptomatic in 81% of HIV-seronegative and 71% of HIV-seropositive patients with PN. CONCLUSIONS: There is a high prevalence of PN in HIV-seronegative IDUs. Although these PNs do not seem to predispose HIV-seropositive IDUs to HIV-related PN, they may increase the likelihood of iatrogenic neuropathy. Intravenous drug users may need more diligent monitoring when administered nucleoside analogues than patients in risk groups with lower endemic rates of PN.

Adult↗
PubMed1999

Risk factors for abomasal displacement in dairy cows.

OBJECTIVE: To determine whether various periparturient events or 305-day milk production during the previous lactation period were associated with abomasal displacement in dairy cows. DESIGN: Retrospective, case-control study. ANIMALS: 75 pairs of case and control cows from 3 university-owned and 3 commercial dairy herds. PROCEDURE: Cows with abomasal displacement were matched with control cows on the basis of herd of origin, breed, age, and calving date. Frequency of specific periparturient events during the period from 2 weeks prior to parturition to diagnosis of abomasal displacement, as well as milk production during the preceding lactation period, were compared between case and control cows. RESULTS: Multivariate analyses indicated that case cows were significantly more likely to have had retained placenta, ketosis, a stillborn calf, metritis, twins, or parturient paresis than were control cows. Dystocia, mastitis, and milk production during the previous lactation period were not associated with abomasal displacement. CLINICAL IMPLICATIONS: Results indicated that a variety of periparturient events were associated with development of abomasal displacement among dairy cows.

Abomasum↗
PubMed1999

Accelerated regression of brain metastases in patients receiving whole brain radiation and the topoisomerase II inhibitor, lucanthone.

PURPOSE: To determine if lucanthone crossed the blood-brain barrier in experimental animals; and to determine accelerated tumor regression of human brain metastases treated jointly with lucanthone and whole brain radiation. METHODS AND MATERIALS: The organ distribution of 3H lucanthone in mice and 125I lucanthone in rats was determined to learn if lucanthone crossed the blood-brain barrier. Size determinations were made of patients' brain metastases from magnetic resonance images or by computed tomography before and after treatment with 30 Gy whole brain radiation alone or with lucanthone. RESULTS: The time course of lucanthone's distribution in brain was identical to that in muscle and heart after intraperitoneal or intravenous administration in experimental animals. Lucanthone, therefore, readily crossed the blood-brain barrier in experimental animals. CONCLUSION: Compared with radiation alone, the tumor regression in patients with brain metastases treated with lucanthone and radiation was accelerated, approaching significance using a permutation test at p = 0.0536.

Animals↗
PubMed1999

The incidence of altered sensation of the mental nerve after mandibular implant placement.

PURPOSE: This study was designed to determine the incidence of altered sensation in patients undergoing mandibular endosseous implant placement. PATIENTS AND METHODS: Ninety-four consecutive patients who underwent the placement of mandibular implants constituted the study group. The only patients that were excluded from this study were those who had preexisting injury to the trigeminal nerve. Patients were followed using standard neurologic testing during the period immediately following implant placement through 6 months. Four hundred five implants were placed in 43 female and 51 male patients. Implant length selection was based on panoramic radiographs using known markers to correct for distortion. In 13 of the patients, the mandibular canal was not adequately visualized, and a computed tomography (CT) scan was used to plan the implant locations. Implants were selected to be located 2 mm above the inferior alveolar canal based on the panoramic images and 1 mm above the canal based on CT images. RESULTS: Eight patients reported altered nerve sensation at their first postimplant visit (8.5%). None of the patients experienced hyperesthesia or dysesthesia. Four of the eight patients with altered sensation had no objective findings or decreased nerve function. One of the patients remained totally anesthetic for 2 months, but reported return to normal function at 4 months. CONCLUSIONS: These findings indicate that a small percentage of patients experience altered sensation after the placement of mandibular endosseous implants. Unlike previous studies, no permanent altered sensation was found. By using proper treatment planning, one can offer endosseous implants with minimal risk of injury to the trigeminal nerve.

Chin↗
PubMed1999

Three oral formulations of methadone. A clinical and pharmacodynamic comparison.

This study was done to determine whether there were any differences in subjective symptoms of opiate withdrawal or methadone pharmacodynamics among patients as they were switched between three different oral formulations of methadone. Patients enrolled in a three-way double-blind crossover trial of three methadone formulations. Subjective symptoms and pharmacodynamic measures were assessed throughout the study period. Eighteen patients were enrolled the study. No statistically significant differences in any of the pharmacodynamic parameters studied were found among the three methadone preparations. There was no significant difference among preparations in the rate and extent of rise and fall in plasma methadone levels during a 24-hour intensive sampling period. Subjective symptoms also did not correlate with methadone formulation. Intolerance to changes in methadone formulation, often observed clinically, do not appear to have a pharmacodynamic basis. Our findings support the notion that such change intolerance reflects factors other than the pharmacologic properties of the different formulations of methadone.

Adult↗
PubMed1999

An evaluation of a family visit education program.

OBJECTIVES: This study was designed to examine the impact of the Family Visit Education Program (FVEP) on family members, nursing staff, and nursing home residents with dementia. DESIGN: The study employed a 2 x 3 single-blind, randomized control group design with two study conditions, FVEP or usual care (UC), and three times of measurement, baseline, 3-months, and 6-months. SETTING: The study was conducted in five skilled-care nursing homes that ranged in size from 120 to 300 beds. PARTICIPANTS: Sixty-six residents with dementia and their primary visitor were randomly assigned to FVEP (n = 32) or UC (n = 34). MEASUREMENTS: Residents were assessed for (1) psychosocial functioning, (2) depression, (3) agitated behavior, and (4) degree of positive social interaction. Nursing staff were assessed for changes in the time and methods used to manage problem behaviors. Visitors were assessed for (1) dementia management skills, (2) extent of perceived caregiving hassles, and (3) visit satisfaction. RESULTS: FVEP was effective for reducing residents' problem behaviors and for decreasing their symptoms of depression and irritability. It was also effective for improving the way family members and other visitors communicated with residents, but, with the exception of reducing the use of mechanical restraints, it was not effective in changing nurses' management of residents' behavior problems. CONCLUSIONS: It is possible to educate family members to communicate and interact more effectively with nursing home residents with dementia. This has beneficial effects on residents but not on nursing staff's management of problem behaviors.

Adult↗
PubMed1999

Southern extension of the range of human babesiosis in the eastern United States.

We sought evidence of babesiosis in three residents of New Jersey who were suspected of local acquisition of Babesia microti infection. We tested serial blood samples from these residents for B. microti antibodies and amplifiable DNA by using immunofluorescent antibody and PCR techniques. All three residents experienced symptoms suggestive of acute babesiosis. The sera of each of the patients reacted against babesial antigen at a titer fourfold or higher in sequentially collected blood samples. PCR-amplifiable DNA, characteristic of B. microti, was detected in their blood. These data suggest that human B. microti infections were acquired recently in New Jersey, extending the range of this piroplasmosis in the northeastern United States.

Adult↗
PubMed1999

Prediction accuracy of soft tissue profile in orthognathic surgery.

The purpose of this study was to compare soft tissue prediction accuracy of model surgery combined with computer software prediction with that of computer software prediction alone and to assess surgical accuracy by comparing the immediate postsurgical cephalogram with the planned movement of skeletal hard tissue. The predicted and actual soft tissue changes and the corresponding skeletal changes of 16 patients were compared using the Quick Ceph Image cephalometric treatment simulation software. A custom analysis was created to measure the hard tissue and soft tissue changes that occurred as a result of the surgical procedure. On average, the predictions were not significantly different from the actual postsurgical profile changes. Surgical changes of hard tissues from presurgery to postsurgery were accurate as planned except for the position of N-ANS. All lower soft tissue points moved significantly during treatment. Quick Ceph Image offers a rapid and reliable method of profile prediction that does not require artistic skill. If predictions are interpreted with caution and transferred accurately to the model surgery, they can provide an excellent visual aid during presurgical treatment planning and patient presentation.

Adolescent↗
PubMed1998

Class restriction of cephalosporin use to control total cephalosporin resistance in nosocomial Klebsiella.

CONTEXT: Resistance to most or all cephalosporin antibiotics in Klebsiella species has developed in many European and North American hospitals during the past 2 decades. OBJECTIVE: To determine if restriction of use of the cephalosporin class of antibiotics would reduce the incidence of patient infection or colonization by cephalosporin-resistant Klebsiella. DESIGN: A before-after comparative 2-year trial. SETTING: A 500-bed, university-affiliated community hospital in Queens, NY. PATIENTS: All adult medical and surgical hospital inpatients. INTERVENTION: A new antibiotic guideline excluded the use of cephalosporins except for pediatric infection, single-dose surgical prophylaxis, acute bacterial meningitis, spontaneous bacterial peritonitis, and outpatient gonococcal infection. All other cephalosporin use required prior approval by the infectious disease section. MAIN OUTCOME MEASURE: Incidence of patient infection or colonization by ceftazidime-resistant Klebsiella during 1995 (control period) compared with 1996 (intervention period). RESULTS: An 80.1% reduction in hospital-wide cephalosporin use occurred in 1996 compared with 1995. This was accompanied by a 44.0% reduction in the incidence of ceftazidime-resistant Klebsiella infection and colonization throughout the medical center (P<.01), a 70.9% reduction within all intensive care units (P<.001), and an 87.5% reduction within the surgical intensive care unit (P<.001). A concomitant 68.7% increase in the incidence of imipenem-resistant Pseudomonas aeruginosa occurred throughout the medical center (P<.01). All such isolates except one were susceptible to other antibiotics. CONCLUSION: Extensive cephalosporin class restriction significantly reduced nosocomial, plasmid-mediated, cephalosporin-resistant Klebsiella infection and colonization. This occurred at the price of increased imipenem resistance in P aeruginosa, which remained susceptible to other agents. Thus, an overall reduction in multiply-resistant pathogens was achieved within 1 year.

Adult↗