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Biomedical subjects

J Worth

Publications and source records attributed to J Worth.

At least 19 recordsLinked to original sources
PubMed2000

Gas-phase production and photoelectron spectroscopy of the smallest fullerene, C20

Fullerenes are graphitic cage structures incorporating exactly twelve pentagons. The smallest possible fullerene is thus C20, which consists solely of pentagons. But the extreme curvature and reactivity of this structure have led to doubts about its existence and stability. Although theoretical calculations have identified, besides this cage, a bowl and a monocyclic ring isomer as low-energy members of the C20 cluster family, only ring isomers of C20 have been observed so far. Here we show that the cage-structured fullerene C20 can be produced from its perhydrogenated form (dodecahedrane C20H20) by replacing the hydrogen atoms with relatively weakly bound bromine atoms, followed by gas-phase debromination. For comparison we have also produced the bowl isomer of C20 using the same procedure. We characterize the generated C20 clusters using mass-selective anion photoelectron spectroscopy; the observed electron affinities and vibrational structures of these two C20 isomers differ significantly from each other, as well as from those of the known monocyclic isomer. We expect that these unique C20 species will serve as a benchmark test for further theoretical studies.

Journal Article↗
PubMed2000

Neonatal sensitization to latex.

Babies born in delivery rooms of hospitals are exposed to latex through skin and mucous membrane contact with prepowdered latex gloves worn by midwives and doctors, and through the inhalation of latex-bound starch powder in the air of the delivery room. This paper examines the hypothesis that they are at risk for latex sensitization, and that part of the sharp increase of childhood asthma, eczema and anaphylaxis in the past 30-40 years may be linked. These possibilities seem hitherto unsuspected. In over 700 papers on latex allergy no mention of neonatal exposure to latex has been found. Even obstetric papers discussing the risks for an atopic mother (atopy - a tendency to develop allergies) do not seem to anticipate any risk for the baby, who might also be atopic. Latex allergy is primarily regarded as an occupational hazard. This paper suggests that it is a hazard for every baby handled by latex gloves at birth.

Cross Reactions↗
PubMed2000

Fears and concerns expressed by families in the donation discussion.

Previous research has identified specific fears and concerns among the general public about organ and tissue donation. However, little to none of that research has dealt with fears and concerns at the time of the donation discussion. In this study, 180 experienced coordinators ranked the fears and concerns most commonly heard during the donation discussion. They further classified the fears and concerns according to the ease with which they can be addressed. Subsequently, the fears and concerns were classified in 4 groups: often heard and easy to deal with, often heard and hard to deal with, seldom heard and easy to deal with, seldom heard and hard to deal with. The results can be used to stimulate further research on family fears and concerns, to train and retrain coordinators to address those concerns in the donation discussion, and to improve existing strategies for increasing organ and tissue donation.

Attitude to Health↗
PubMed2000

Overcoming families' fears and concerns in the donation discussion.

Research into the fears and concerns families have about donation and other issues at the time of the donation discussion substantiates that many fears and concerns act as impediments to consent. Twenty fears and concerns voiced by families at the time of the donation discussion have been identified. Specific strategies have been developed to deal with 19 of those concerns. Using gentle probing questions and targeted strategies, trained requestors may successfully address many fears and concerns, thus increasing the likelihood of the family consenting to donation.

Family↗
PubMed1999

Dealing with the fear of mutilation in the donation discussion.

Fear of mutilation is a significant barrier to organ and tissue donation. It constitutes an example of Mystical Thinking and may be seen as an exemplar of animal learning or, more specifically, as a representation of the "blood phobia." As such the fear is not amenable to conventional public education efforts. Cognitive and behavioral techniques used in treating other types of phobias should be studied as a way to remove this barrier to donation.

Animals↗
PubMed1999

Neonatal sensitisation to latex: a hypothesis.

The exposure of babies to latex gloves at birth may be behind the dramatic increase in childhood allergies in the past 40 years. Jennifer Worth explores this theory and calls for a ban on the use of pre-powdered latex gloves in maternity units.

Cross Reactions↗
PubMed1998

Adequate consent: its content in the donation discussion.

Although recent research has established a relationship between donation rates and the consent process for organ and tissue donation, little attention has been given to the content of the donation discussion. Recent studies suggest that families want more information to aid them in making the decision to consent. To address the family's needs, the interviewer should introduce the subject appropriately, respond fully to the family's questions, and provide the following information: the options of donating particular organs or tissues, the potential benefits of donation, the right not to donate, the effects on the funeral, the lack of cost of donation to the family, a description of the procurement procedures, and what will happen if the donated organs cannot be used for transplant.

California↗
PubMed1997

Biases among hospital personnel concerning donation of specific organs and tissues: implications for the donation discussion and education.

Previous research has established that healthcare professionals who are being trained to talk with families about donation have strong personal preferences for and aversions to the donation of specific organs and tissues. This article examines the possible reasons for such preferences and/or aversions. Among the population studied, strong personal preferences for donation of specific anatomical gifts predominantly were associated with pragmatic and moral or ethical justifications. Strong aversions were associated with pragmatic reasoning and mystical thinking, represented as ancient fears. The findings suggest the need for changes in the way the donation option is offered to families and the way hospital personnel are educated.

Attitude of Health Personnel↗
PubMed1997

Reservations and preferences among procurement professionals concerning the donation of specific organs and tissues.

Previous research has established that organ procurement professionals who talk with families about donation have strong personal preferences concerning the donation of specific organs and tissues. This study examines possible reasons for such preferences and compares them with those of hospital personnel who talk with families about donation. The findings suggest that preferences among procurement personnel closely resemble those of hospital personnel, but procurement professionals' reasons reflect a slightly higher rate of self-interest. Aversions among procurement personnel differ from those of hospital personnel. Procurement personnel have fewer aversions to donating eyes and skin and more aversions to bone, and their aversions are more likely to reflect professional experience with particular donations. The findings suggest the need for changes both in the way donation options are offered to families and the way hospital and procurement personnel are educated.

Attitude of Health Personnel↗
PubMed1996

High levels of anti-HIV-1 envelope antibodies in cerebrospinal fluid as compared to serum from patients with AIDS dementia complex.

The antibody response to the HIV-1 envelope protein has not been well characterized in patients with AIDS dementia complex (ADC). We evaluated the frequency of antibodies against the HIV-1 envelope in cerebrospinal fluid (CSF) and serum from 21 persons with ADC and 10 symptom-free HIV-1-positive subjects using Western immunoblot with reducing and nonreducing buffer and radioimmunoprecipitation (RIP) analysis. RIP analysis revealed anti-envelope antibodies in all sera tested. Higher anti-envelope levels were observed in CSF than in serum of 12 of 21 ADC patients and only 1 of 10 symptom-free subjects (two-sided Fisher exact test, p < 0.05). All persons with moderate to severe ADC had higher anti-envelope levels in CSF than in sera (p < 0.005). CSF anti-gp120 antibodies were not as readily detected by Western blot analysis even under nonreduced conditions, suggesting that they are directed to conformational epitopes. Higher CSF anti-envelope antibodies appear to be more common in patients with ADC than in symptom-free HIV-1-positive subjects. This antibody pattern may serve as a marker for ADC and its progression.

AIDS Dementia Complex↗
PubMed1996

The case against more public education to promote organ donation.

The organ procurement community has always considered public education a primary challenge. According to conventional wisdom, greater awareness generated by public education will lead to more donated organs. This notion may be based on faulty assumptions about public education and about the relationship between awareness and behavior. Public education, as the primary focus for the organ procurement community, should be abandoned. Increased efforts in professional education and basic research are more appropriate endeavors for organ procurement organizations.

Attitude of Health Personnel↗
PubMed1995

EEG abnormalities in patients with atypical panic attacks.

BACKGROUND: Panic attacks and certain partial seizures have phenomenologic similarities which suggest that they may somehow be related. No evidence of such a relationship, however, was found when the routine EEGs of patients with panic attacks were examined. METHOD: Fifteen subjects with atypical panic attacks who met DSM-III-R criteria for panic disorder agreed to have routine followed by prolonged ambulatory EEG monitoring with sphenoidal electrodes. Fourteen subjects actually underwent monitoring; 1 had a panic attack during premonitoring routine EEG. RESULTS: Focal paroxysmal EEG changes consistent with partial seizure activity occurred during panic attacks in 33% (N = 5) of the 15 subjects; 2 (40%) of the 5 subjects with panic-related EEG changes had normal routine EEGs. Multiple attacks were recorded before panic-related EEG changes were demonstrated in several subjects. CONCLUSION: It may be necessary to monitor the EEG during multiple panic attacks to reveal an association between atypical panic attacks and epileptiform EEG changes.

Adult↗
PubMed1993

Human immunodeficiency virus type 1-specific cytotoxic T lymphocytes release gamma interferon, tumor necrosis factor alpha (TNF-alpha), and TNF-beta when they encounter their target antigens.

Human immunodeficiency virus type 1 (HIV-1) infection is associated with elevated levels of inflammatory cytokines in the serum and cerebrospinal fluid of infected persons, but the sources of these proteins as well as the specific stimuli which trigger their production and release have not been fully defined. In this study, we evaluated the ability of HIV-1-specific cytotoxic T-lymphocyte (CTL) clones derived from seropositive persons to release gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and TNF-beta upon contact with target cells presenting viral antigen. Peripheral blood- and cerebrospinal fluid-derived HIV-1-specific CD3+ CD4- CD8+ CTL clones as well as freshly isolated peripheral blood mononuclear cells from infected persons were tested in parallel for HIV-1-specific cytotoxicity and cytokine release. Target cells consisted of autologous and allogeneic B-lymphoblastoid cell lines sensitized with synthetic HIV-1 peptides containing the epitopes recognized by these CTL. Cytokine production was measured by specific enzyme-linked immunosorbent assay of culture supernatant fluid. HIV-1-specific CTL clones directed at envelope, Gag, reverse transcriptase, and Nef epitopes specifically released IFN-gamma, TNF-alpha, and TNF-beta upon contact with their relevant target epitopes but not following contact with irrelevant epitopes. These cytokines were released in an HLA class I-restricted fashion, and release was detectable as early as 4 to 6 h of incubation and remained elevated at 48 h. Fresh peripheral blood mononuclear cells from a seropositive person likewise released IFN-gamma in an antigen-specific and HLA class I-restricted manner when incubated with target cells presenting a peptide containing a CTL epitope, paralleling the HIV-specific cytolytic activity of these cells. These studies indicate that in addition to mediating direct cytotoxicity, HIV-1-specific CTL may affect other immune responses by releasing IFN-gamma, TNF-alpha, and TNF-beta. Elevated levels of these cytokines which have been detected in serum and cerebrospinal fluid of infected persons may be due at least in part to the persistent HIV-1-specific CTL response.

Amino Acid Sequence↗
PubMed1993

Focal paroxysmal EEG changes during atypical panic attacks.

Atypical panic attacks include features such as focal paresthesias or sensory distortions, but attempts to demonstrate a relationship to partial seizures have been unsuccessful. Two patients with atypical panic attacks had attacks during EEG monitoring: one during a routine EEG in the EEG laboratory, the other at home during ambulatory monitoring. Focal paroxysms of sharp wave activity appeared on both patients' EEGs coincident with the spontaneous onset of panic attack symptoms. Both patients remained conscious. The correlation of focal paroxysmal EEG changes with panic attack symptoms suggests that these attacks were produced by partial seizure activity. Further study of the relationship between panic attacks and seizures is indicated.

Adult↗
PubMed1992

Detection of a vigorous HIV-1-specific cytotoxic T lymphocyte response in cerebrospinal fluid from infected persons with AIDS dementia complex.

AIDS dementia complex is a common neurologic disorder in later stages of HIV-1 infection. Because virus-specific CTL have been shown to contribute to neurologic disease in certain viral illnesses, we examined the cerebrospinal fluid of HIV-1-infected persons with various stages of AIDS dementia complex for the presence of HIV-1-specific CTL. In five of six subjects studied, HIV-1-specific CTL were identified in the cerebrospinal fluid. These CTL were directed at epitopes within the gag, reverse transcriptase, envelope, and nef proteins and restricted by HLA class I Ag. In four of these subjects, virus-specific CTL were detected in higher numbers in the cerebrospinal fluid compared to the peripheral blood, suggesting a specific recruitment to or local induction within the nervous system. These studies demonstrate the presence of a vigorous and broadly directed CTL response to HIV-1 in the central nervous system of infected persons with AIDS dementia complex, and provide immunologic evidence of localized intrathecal infection. Although HIV-1-specific CTL may serve to inhibit viral replication in the central nervous system, the presence of a persistent CTL response in the central nervous system may also contribute to the neurologic disorders characteristic of HIV-1 infection.

AIDS Dementia Complex↗
PubMed1992

A comparison of brain perfusion SPECT in cocaine abuse and AIDS dementia complex.

Intravenous drug use is a major risk factor for HIV-1 infection. Since both AIDS dementia complex (ADC) and cocaine have been associated with abnormal brain perfusion imaging, we compared the scintigraphic patterns of ADC patients and cocaine polydrug users with normal control subjects using 99mTc-HMPAO SPECT. We found a high incidence of cortical defects in both ADC (100%) and cocaine-dependent (90%) subjects. In the cocaine and ADC patients, cortical defects were most frequent in the frontal, temporal and parietal lobes and occurred with similar frequency in the two populations. In both groups, the number of cortical defects per subject was higher than normal subjects (10.0 +/- 5.0 for ADC, 10.1 +/- 5.2 for cocaine and 0.7 +/- 1.5 for normal), background activity was high (a 65% and 60% incidence for ADC and cocaine, respectively), and basal ganglia involvement was frequent (40% and 65% for ADC and cocaine). We conclude that the brain perfusion pattern, while a sensitive indicator of ADC, cannot be distinguished from chronic cocaine polydrug use and caution should therefore be applied before entertaining a specific diagnosis.

AIDS Dementia Complex↗