Search PubMed⌕ Search

Biomedical subjects

C Kennedy

Publications and source records attributed to C Kennedy.

At least 55 records · Page 3Linked to original sources
PubMed2001

Chest pain following oesophageal stenting for malignant dysphagia.

AIM: The palliative use of self-expanding metallic stents has been widely reported to relieve dysphagia in cases of oesophageal carcinoma. Little has been documented on the severity of chest pain following oesophageal stenting. The aim of this study was to investigate the association of pain with oesophageal stenting for malignant dysphagia. METHODS: Fifty-two patients with inoperable oesophageal carcinoma underwent stent placement between 1995-1999. Daily opioid analgesic requirements (mg of morphine equivalent doses) were monitored for 3 days before and 7 days after stenting. The degree of palliation was expressed as a dysphagia score (0-3). Hospital stay, readmission days, stent complications and patient survival time were also recorded. RESULTS: Twenty-six patients (50%) required opioid analgesia for chest pain (median dose: 80 mg morphine/day) within 48 h of the procedure compared to 11 (21.2%) patients before stenting (P = 0.0041). A significant increase was evident in the analgesic consumption following stent deployment (P < 0.001). The dysphagia score improved by a median value of 1 (CI 0.25)P < 0.001, with a re-intervention rate of 11.5%. The median survival time was 40 days post stenting (range 1-120). CONCLUSION: A significant proportion of patients developed chest pain after oesophageal stenting, requiring high dose opioid analgesia. As the origin of the pain is still unknown, pre-emptive analgesia may a play role in reducing stent-related morbidity and possibly in-hospital stay.

Adult↗
PubMed2001

Comparison of benefit to sugarcane plant growth and 15N2 incorporation following inoculation of sterile plants with Acetobacter diazotrophicus wild-type and Nif- mutants strains.

The ability of the nitrogen-fixing bacterial endophyte Acetobacter diazotrophicus strain PAl5 to enhance the growth of sugarcane SP70-1143 was evaluated in the growth chamber, greenhouse, and field by comparing plants inoculated with wild-type and Nif mutant MAd3A in two independent experiments. The wild-type and Nif mutant strains colonized sugarcane plants equally and persisted in mature plants. In N-deficient conditions, sugarcane plants inoculated with A. diazotrophicus PAl5 generally grew better and had a higher total N content 60 days after planting than did plants inoculated with mutant MAd3A or uninoculated plants. These results indicate that the transfer of fixed N from A. diazotrophicus to sugarcane might be a significant mechanism for plant growth promotion in this association. When N was not limiting, growth enhancement was observed in plants inoculated with either wild-type or Nif- mutants, suggesting the additional effect of a plant growth promoting factor provided by A. diazotrophicus. A 15N2 incorporation experiment demonstrated that A. diazotrophicus wild-type strains actively fixed N2 inside sugarcane plants, whereas the Nif- mutants did not.

Acetobacter↗
PubMed2001

Utilization and practical aspects of tele-ophthalmology between South Africa and the UK.

A tele-ophthalmology service was established between a regional hospital in South Africa and a specialist eye hospital in the UK. The aim of the service was to provide secondary specialist advice in the diagnosis and treatment of difficult ophthalmology cases in South Africa. Over 12 months, the South African medical officers saw 16,458 ophthalmology patients and would have liked a second opinion in 5.7% of these cases. Case discussions conducted by videoconferencing at 384 kbit/s were carried out in 0.5% of cases. No significant connection problems were experienced during the 12-month study period. On 4% of occasions, the case discussions were conducted at a bandwidth of 256 kbit/s, but this did not affect the quality of the still images. The South African medical officers valued the educational benefits gained from the case discussions with the UK specialists.

Diagnostic Techniques, Ophthalmological↗
PubMed2001

Subspecialty adnexal ophthalmological examination using telemedicine.

We studied the clinical outcome of examination of a group of patients with adnexal (eyelid and orbit) conditions. Seventeen patients with adnexal problems were assessed by an ophthalmologist at a distance using telemedicine, and then subsequently by an ophthalmologist in a face-to-face consultation. Measurements such as palpebral aperture, levator muscle function and eyelid skin crease position were recorded. The clinical outcomes from both consultations were recorded independently by the consultants and then compared. The study showed that certain adnexal conditions, such as congenital and involutional ptosis, could be accurately assessed using telemedicine, but that other conditions, such as socket problems in patients who had a previous enucleation or those with non-specific ocular pain with less clear-cut features, were better assessed in a face-to-face consultation. Overall, teleconsultations appeared to be suitable for the assessment of uncomplicated ptosis but not for less well defined conditions. Other factors, such as family dynamics and language problems, also limited the usefulness of the technique.

Communication Barriers↗
PubMed2001

Videoconferencing in the Queensland health service.

Videoconferencing was introduced in the Queensland health service in 1995. By the end of 1999, there were more than 150 videoconferencing units in health facilities around the state. Six audits of videoconferencing usage were conducted using similar methodology at six-month intervals from November 1997 to May 2000. Between November 1997 and November 1999, the number of calls more than doubled, from 566 to 1378. Hours of usage almost trebled, from 671 to 1724. The average duration of calls remained similar, at about 1 h 12 min. The proportion of calls involving more than two sites (multipoint videoconferences) increased from 44% to 65%. The majority of the activity was for education (including training). Videoconferencing was also used for administration and clinical care. Mental health staff were the heaviest users, but use by health professionals from other specialty areas increased during the study period. The Queensland health service has realized a number of important benefits from telehealth.

Community Networks↗
PubMed2001

International union of pharmacology. XXIV. Current status of the nomenclature and properties of P2X receptors and their subunits.

ATP acts as a humoral mediator to control cell function extracellularly. The receptors that mediate the actions of ATP belong to two classes, the metabotropic P2Y receptors and the transmitter-gated, ion channel P2X receptors. This review describes the structure, distribution, function, and ligand recognition characteristics of P2X receptors, which comprise seven distinct subunits that can function as both homo- and hetero- polymers. The pharmacology of P2X receptors is complicated by marked differences between species orthologues. The current nomenclature is based largely on recombinant receptor studies and detailed knowledge of endogenous P2X receptors in native tissues is limited because of lack of good selective agonists and antagonists for each receptor type.

Animals↗
PubMed2001

Differences between couples who end their marriage by fault or no-fault legal procedures.

Spouses from 53 couples who ended their marriage by dissolution (DS), a form of no-fault divorce, were compared with spouses from 59 couples who ended their marriage by fault-based divorce (DV). DV husbands were younger than DS husbands. DV couples were less likely to have pooled finances, and they had more sons than did DS couples. For growth curves over the first 4 years of marriage, relative to DS wives, DV wives had lower starting levels for liking of spouse, trust, and marital quality; higher starting levels for dysfunctional beliefs about relationships and psychological distress; weaker declines in extrinsic motives for being married; and stronger declines for love for spouse. Relative to DS husbands, DV husbands showed a stronger increase in dysfunctional beliefs about relationships.

Adult↗
PubMed2001

Daughters and mothers exercising together (DAMET): a 12-week pilot project designed to improve physical self-perception and increase recreational physical activity.

This paper presents the results of a 12-week single-sex, family-based physical activity intervention grounded in Social Cognitive Theory. Mother/daughter pairs and triads (n = 20) attended physical activity and classroom sessions twice weekly. Physiological data (VO2peak, height, and weight), psychological data (physical self-perception profile subscale scores), information about physical activity participation (PAP, d x wk(-1)) and qualitative impressions (QI) of the program were collected pre- and post-intervention. PAP and QI were also collected 6-months after completing the intervention. Although no significant increases in physical activity were reported, significant improvements in perceived sport competence, physical condition, and strength and muscularity were reported over time. The social cognitive theory, as used to plan this physical activity intervention, offered a promising theoretical perspective for facilitating improved physical self-perception in adolescent girls and their mothers.

Adolescent↗
PubMed2000

False positives in universal neonatal screening for permanent childhood hearing impairment.

High rates of false-positive neonatal screens for permanent childhood hearing impairment (PCHI) associated with raised hearing thresholds lead to unnecessary assessments of the baby, which may worry parents. False-positive rates need to be reduced, especially in view of the UK government's announcement that national neonatal screening will be introduced. We report screening criteria that give a six-fold reduction in false-positive rates.

Deafness↗
PubMed2000

The discovery and development of P2 receptor subtypes.

Extracellular purine and pyrimidine nucleotides modulate cellular activity by acting at P2 receptors. The first receptor to be identified was the P(2)-purinoceptor, which was characterised and named in 1978. In the 1980s this site was subdivided into P(2X) and P(2Y) purinoceptors on the basis of pharmacological criteria in functional studies on native receptors. Subsequently, a similar approach led to the characterisation of the P(2T), P(2Z), P(2U) and P(2D) purinoceptors. In the 1990s a molecular biological approach has led to the cloning and functional expression of at least 12 mammalian P2 receptor subtypes. The challenge now is to relate these recombinant receptors to native receptors present within a wide range of tissues.

Animals↗
PubMed2000

P2Y receptor-mediated inhibition of tumor necrosis factor alpha -stimulated stress-activated protein kinase activity in EAhy926 endothelial cells.

In the EAhy926 endothelial cell line, UTP, ATP, and forskolin, but not UDP and epidermal growth factor, inhibited tumor necrosis factor alpha (TNFalpha)- and sorbitol stimulation of the stress-activated protein kinases, JNK, and p38 mitogen-activated protein (MAP) kinase, and MAPKAP kinase-2, the downstream target of p38 MAP kinase. In NCT2544 keratinocytes, UTP and a proteinase-activated receptor-2 agonist caused similar inhibition, but in 13121N1 cells, transfected with the human P2Y(2) or P2Y(4) receptor, UTP stimulated JNK and p38 MAP kinase activities. This suggests that the effects mediated by P2Y receptors are cell-specific. The inhibitory effects of UTP were not due to induction of MAP kinase phosphatase-1, but were manifest upstream in the pathway at the level of MEK-4. The inhibitory effect of UTP was insensitive to the MEK-1 inhibitor PD 098059, changes in intracellular Ca(2+) levels, or pertussis toxin. Acute phorbol 12-myristate 13-acetate pretreatment also inhibited TNFalpha-stimulated SAP kinase activity, while chronic pretreatment reversed the effects of UTP. Furthermore, the protein kinase C inhibitors Ro318220 and Go6983 reversed the inhibitory action of UTP, but GF109203X was ineffective. These results indicate a novel mechanism of cross-talk regulation between P2Y receptors and TNFalpha-stimulated SAP kinase pathways in endothelial cells, mediated by Ca(2+)-independent isoforms of protein kinase C.

Cell Line↗
PubMed2000

HIV as a chronic disease: implications for long-term care at an AIDS-dedicated skilled nursing facility.

OBJECTIVE: To describe the characteristics and outcomes of the first 3 years of admissions to a dedicated skilled nursing facility for people with acquired immunodeficiency syndrome (AIDS). METHODS: Systematic chart review of consecutive admissions to a 30-bed, AIDS-designated long-term care facility in New Haven, Connecticut, from October 1995 through December 1998. RESULTS: The facility has remained filled to 90% or more of its bed capacity since opening. Of 180 patients (representing 222 admissions), 69% were male; mean age was 41 years; 57% were injection drug users; 71% were admitted directly from a hospital. Leading reasons for admission were (1) the need for 24-hour nursing/medical supervision, (2) completion of acute medical treatment, and (3) terminal care. On admission, the median Karnofsky score was 40, and median CD4+ cell count was 24/mm3; 48% were diagnosed with serious neurologic disease, 44% with psychiatric illness; patients were receiving a median of 11 medications on admission. Of 202 completed admissions, 44% of patients died, 48% were discharged to the community, 8% were discharged to a hospital. Median length of stay was 59 days (range 1 to 1,353). Early (< or = 6 months) mortality was predicted by lower admission CD4+ count, impairments in activities of daily living, and the absence of a psychiatric history; long-term stay (> 6 months) was predicted by total number of admission medications, neurologic disease, and dementia. Comparison of admissions from 1995 to 1996 to those in 1997 to 1998 indicated significantly decreased mortality rates and increased prevalence of psychiatric illness between the two periods (P < .01). CONCLUSIONS: A dedicated skilled nursing facility for people with AIDS can fill an important service need for patients with advanced disease, acute convalescence, long-term care, and terminal care. The need for long-term care may continue to grow for patients who do not respond fully to current antiretroviral therapies and/or have significant neuropsychiatric comorbidities. This level of care may be increasingly important not only in reducing lengths of stay in the hospital, but also as a bridge to community-based residential options in the emerging chronic disease phase of the AIDS epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Mental health service use by Americans with severe mental illnesses.

BACKGROUND: The aim of this study was to determine the patterns and determinants of service use in severely mentally ill persons drawn from the National Institute of Mental Health Epidemiological Catchment Area (ECA) program, a community-based epidemiologic survey. This information provides a baseline against which to track ongoing changes in the US mental health service system. METHODS: Severe mental illness (SMI) was defined according to US Senate Appropriations Committee guidelines. Comparisons were made with persons who had a mental disorder that did not meet these criteria (non-SMI). Sociodemographic factors, and 1-year volume and intensity of mental or addictive services use were determined. Differences between those who used services and those who did not were examined using logistic regression. RESULTS: Persons with SMI differed from persons with non-SMI in most sociodemographic characteristics. A higher proportion of persons with SMI used ambulatory services, but the mean number of visits per person did not differ from the non-SMI population. Persons with SMI comprised the bulk of hospital inpatients admitted during a 1-year period. Several significant sociodemographic determinants of service use were found, with different patterns for general medical and specialty service use, pointing out potential barriers to care. CONCLUSIONS: As health care reform measures continue to be debated, attention to the service needs of the severely mentally ill is of crucial importance. Pre-managed care (pre-1993) baseline service use benchmarks will be essential to assess the impact of managed care on access to care, particularly for the severely mentally ill. Periodic collection of epidemiologic data on prevalence and service use would thus greatly facilitate service planning and addressing barriers to receiving mental health services in this population.

Adolescent↗
PubMed2000

HLA and other host factors in transfusion-acquired HIV-1 infection.

The host and viral factors that underlie infection with HIV-1 vary considerably with some individuals progressing to AIDS within 3 to 5 years after infection, whereas others remain clinically asymptomatic for over 10 years. Host factors that may contribute to disease progression include HLA and allelic variants of the chemokine receptors CCR5 and CCR2, which have been shown to influence both long-term survival and rapid progression. In this study, we have examined the contribution of HLA and polymorphisms in CCR5 and CCR2 to long-term survival in transfusion-acquired HIV-1-infected individuals. We have found a higher number of HLA-A32 and -A25 alleles but a lower number of the HLA-B8 allele in the study group compared with the frequencies seen in the HIV-1-negative Australian caucasian population. However, there was no apparent contribution by allelic variants of CCR5 and CCR2 to long-term survival and the combined influence of HLA and CCR polymorphisms could not be evaluated in this relatively small (n = 20) group of study subjects. The results of this work support a role for HLA in long-term nonprogression though the presence in the Sydney Blood bank Cohort of nef-defective HIV-1 may confound associations between certain HLA alleles and long-term survival in the face of infection with HIV-1.

Adult↗
PubMed2000

The effect of P2 receptor antagonists and ATPase inhibition on sympathetic purinergic neurotransmission in the guinea-pig isolated vas deferens.

1. Intracellular microelectrodes were used to record the transmembrane potential and excitatory junction potentials (e.j.p.s) produced by sympathetic nerve stimulation (1 Hz) in smooth muscle cells of the guinea-pig isolated vas deferens. 2. The symmetrical 3'-urea of 8-(benzamido)naphthalene-1,3,5-trisulphonic acid (NF023) produced a concentration-dependent inhibition of e.j.p. magnitude (IC(50)=4. 8x10(-6) M), but had no effect on the resting membrane potential of the smooth muscle cells. 3. Pyridoxal-5-phosphate (P-5-P) also depressed e.j.p. magnitude in a concentration-dependent manner, but was less potent than NF023 (IC(50)=2.2x10(-5) M). At 10(-4) M and above P-5-P significantly depolarized the smooth muscle cells. 4. The nucleoside triphosphatase inhibitor 6-N,N-diethyl-D-beta, gamma-dibromomethyleneATP (ARL 67156) (5x10(-5) M) significantly increased e.j.p. amplitude. ARL 67156 (10(-4) M) further increased e. j.p. amplitude such that they often reached threshold for initiation of action potentials, causing muscle contraction and expulsion of the recording electrode. 5. After reduction of e.j.p.s by NF023 or P-5-P (both 10(-5) M), subsequent co-addition of ARL 67156 (10(-4) M) significantly increased their magnitude. 6. The overflow of endogenous ATP evoked by field stimulation of sympathetic nerves (8 Hz, 1 min) was measured by HPLC and flurometric detection. ARL 67156 (10(-4) M) enhanced ATP overflow by almost 700% compared to control. 7. We conclude that for electrophysiological studies NF023 is preferable to other P2X receptor antagonists such as pyridoxalphosphate -6-azophenyl-2',4'-disulphonic acid (PPADS), suramin or P-5-P. Furthermore, breakdown of endogenous ATP by nucleoside triphosphatases is an important modulator of purinergic neurotransmission in the guinea-pig vas deferens.

Adenosine Triphosphatases↗
PubMed2000

Characterization of the ATPase released during sympathetic nerve stimulation of the guinea-pig isolated vas deferens.

The release of ATPase activity evoked by electrical field stimulation (EFS) (8 Hz, 25 s) was investigated in several tissues in which adenosine 5'-triphosphate (ATP) acts as a neurotransmitter. Superfusate collected during EFS of sympathetic nerves of the guinea-pig, rat and mouse isolated vas deferens and parasympathetic nerves of the guinea-pig isolated urinary bladder contained ATPase activity. ATP breakdown was fastest in superfusate collected from the guinea-pig isolated vas deferens. However, EFS of the enteric nerves of the guinea-pig isolated taenia coli did not release any detectable ATPase. The ATPase released from the guinea-pig isolated vas deferens metabolized ATP at similar rates at incubation temperatures of 37 degrees C and 20 degrees C. Lineweaver-Burke analysis of the initial rates of ATP hydrolysis gave a K(M) of 39 microM and a V(max) of 1039 pmol ATP metabolized min(-1) ml(-1) superfusate. 6-N,N-diethyl-D-beta,gamma-dibromomethyleneATP (ARL 67156), pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) and pyridoxal-5'-phosphate (P-5-P) all inhibited the ATPase activity in a concentration-dependent manner with a potency order of ARL 67156 = PPADS>P-5-P. In conclusion, EFS of several tissues in which ATP is a neurotransmitter causes the release of an ATPase and activity is greatest in the guinea-pig vas deferens. The enzyme has pharmacological and kinetic characteristics that are similar to ectonucleoside triphosphate diphosphohydrolases.

Adenosine Triphosphatases↗
PubMed2000

Release of a soluble ATPase from the rabbit isolated vas deferens during nerve stimulation.

The properties of the ATPase released during electrical field stimulation (EFS) (8 Hz, 25 s) of the sympathetic nerves of the superfused rabbit isolated vas deferens were investigated. Superfusate collected during EFS rapidly metabolised exogenous ATP (100 microM) and 50% was broken down in 5.67+/-0.65 min. The main metabolite was ADP, virtually no AMP was produced and adenosine was absent. No enzyme activity was seen in samples collected in the absence of EFS. Lineweaver-Burke analysis of the initial rates of ATP hydrolysis gave a K(M) of 40 microM and V(max) of 20.3 nmol ATP metabolized min(-1) ml(-1) superfusate. ATPase activity was unaffected by storage at room temperature for 24 h, but was abolished at pH4 or by heating at 80 degrees C for 10 min. ARL 67156 inhibited ATP breakdown in a concentration-dependent manner (IC(50)=25 microM (95% confidence limits=22-27 microM), Hill slope=-1.06+/-0.04). When EFS was applied three times at 30 min intervals, ATP metabolism was 20-30% less in superfusate collected during the second and third stimulation periods compared with the first. ATPase activity was released in a frequency-dependent manner, with significantly greater activity seen after stimulation at 4 and 8 Hz than at 2 Hz. In conclusion, EFS of the sympathetic nerves in the rabbit vas deferens causes release of substantial ATPase, but little ADPase activity into the extracellular space. This contrasts with the guinea-pig vas deferens, which releases enzymes that degrade ATP to adenosine. Thus, the complement of enzymes released by nerve stimulation is species-dependent.

Adenosine Triphosphatases↗