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Biomedical subjects

M McCarthy

Publications and source records attributed to M McCarthy.

At least 181 records · Page 10Linked to original sources
PubMed1998

Vascular resistance and the efficacy of red cell substitutes in a rat hemorrhage model.

We have compared polyethylene glycol-modified bovine hemoglobin (PEG-Hb; high O2 affinity, high viscosity, high oncotic pressure) and human hemoglobin cross-linked between the alpha-chains (alpha alpha-Hb; low O2 affinity, low viscosity, low oncotic pressure) with a non-O2-carrying plasma expander (pentastarch, high viscosity and oncotic pressure) after a 50% (by volume) exchange transfusion followed by a severe (60% of blood volume) hemorrhage. Mean arterial pressure and systemic vascular resistance rose significantly in the alpha alpha-Hb but not in the PEG-Hb animals. Two-hour survival was greater in the PEG-Hb animals (93%) than in control (35%), pentastarch (8%), or alpha alpha-Hb (6%) animals. In the PEG-Hb animals, there was no disturbance of acid-base balance, significantly less accumulation of lactic acid, and higher cardiac output than in the other groups. The data suggest that the rise in vascular resistance that follows alpha alpha-Hb exchange transfusion offsets the additional O2 transport provided by the cell-free hemoglobin. When resistance does not rise, as with PEG-Hb, even relatively small amounts of cell-free hemoglobin appear to be a very effective blood replacement.

Animals↗
PubMed1998

Specialist palliative care in nonmalignant disease.

The objective of this study was to investigate how many patients who die from causes other than cancer might benefit from specialist palliative care. This was achieved by secondary analysis of data from the Regional Study of Care for the Dying, a retrospective national population-based interview survey. The investigation involved 20 self-selected English health districts, nationally representative in terms of social deprivation and most aspects of health services provision. A total of 3696 patients were randomly selected from death registrations in the last quarter of 1990; an interview concerning the patient was completed 10 months after the death by bereaved family, friends or officials. The results show that a third (243/720) of cancer patients who were admitted to hospices or had domiciliary palliative care scored at or above the median on three measures of reported symptom experience in the last year of life. That is the number of symptoms (eight or more), the number of distressing symptoms (three or more) and the number of symptoms lasting more than six months (three or more). A total of 269 out of 1605 noncancer patients (16.8%) fulfilled these criteria. On this basis, it is estimated that 71,744 people who die from nonmalignant disease in England and Wales each year may require specialist palliative care. An increase of at least 79% in caseload would, therefore, be expected if specialist palliative care services were made fully available to noncancer patients. This is a conservative estimate, as non-cancer patients were matched to only one-third of cancer patients who had specialist palliative care. It is concluded that clinicians and patient groups caring for patients with advanced nonmalignant disease must work together with specialist palliative care services and with health commissioners to develop, fund and evaluate appropriate, cost-effective services which meet patient and family needs for symptom control and psychosocial support.

Female↗
PubMed1998

HIV-1 strain-associated variability in infection of primary neuroglia.

Qualitative differences among strains of Human Immunodeficiency Virus type 1 (HIV-1) may influence viral infectivity for cells of the central nervous system (CNS) and determine or at least significantly influence the neuropathogenesis of brain infection. In this study, we compared infectivity for these cells in vitro among several different laboratory-adapted HIV-1 strains differing in cellular tropism. These strains included three lymphotropic strains (SF2, NL4-3, and SG3.1), two macrophage-tropic strains (SF128A, SF162), and one brain-derived strain (YU2). In microglia, macrophage-tropic strain SF128A established productive infection while the lymphotropic strain SF2 did not. In infected astrocytes, all HIV-1 strains transiently produced variable and much lower levels of p24 antigen. Viral DNA env or tat gene sequences were amplified from infected astrocytes; the amplified signals varied among HIV-1 strains, but the strongest viral DNA signals were obtained from cells infected by the lymphotropic strains SF2 and SG3.1. Transfection of astrocytes with infectious HIV-1 proviral DNA clones confirmed the observation that HIV-1 strains differ in their ability to replicate in astrocytes. Transfection revealed post-entry blocks to replication by macrophage-tropic proviruses pSF128A and pSF162. However, cytomegalovirus (CMV) superinfection of transfected astrocytes enhanced p24 production by lymphotropic HIV-1 proviruses twofold and stimulated p24 production by the otherwise inactive macrophage-tropic proviruses. This study demonstrates the spectrum of HIV-1 strain-associated variation in infectivity for neuroglia, and suggests, in addition, that herpesviral factors or viral-induced cellular factors may stimulate HIV-1 infection in astrocytes and expand the neural cell tropism of certain HIV-1 strains.

Cells, Cultured↗
PubMed1998

Cytomegalovirus and human herpesvirus-6 trans-activate the HIV-1 long terminal repeat via multiple response regions in human fetal astrocytes.

Cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) infection stimulated HIV-1 replication and trans-activated the HIV-1 promoter (the long terminal repeat or LTR) to a similar extent in transfected, nonimmortalized, human fetal astrocytes. CMV infection increased basal LTR expression by approximately sevenfold, while HHV-6 infection increased basal LTR expression by fourfold. This enhancing effect required cell-cell contact between CMV-infected or HHV-6-infected and LTR-containing cells. To determine the target regions on the HIV promoter that respond to CMV and HHV-6 trans-activation, several modified LTR-reporter gene constructs were tested. Loss of functional NFkappaB, Sp1, or upstream modulatory sites on the LTR caused significant reduction ofbasal LTR expression in astrocytes. These elements also mediated the trans-activation events during HHV-6 or CMV infection in astrocytes, though to varying degrees. Electrophoretic mobility shift assays (EMSA) indicated that core, enhancer, and upstream modulatory regions of the LTR interacted specifically with nuclear proteins from both uninfected and CMV- or HHV-6-infected human fetal astrocytes. CMV or HHV-6 infection did not appear to induce unique, LTR-specific nuclear binding proteins, but rather enhanced the relative proportion of some of the existing protein complexes, in particular, the complexes formed with the AP-1 binding sites on the HIV-1 LTR (nt - 354 to - 316). Our data suggest that CMV or HHV-6 trans-activation of HIV LTR activity in human fetal astrocytes proceeds via intracellular molecular interactions involving herpesviral gene products, cellular proteins, and multiple sites on the LTR upstream of the TATA box. The pattern of LTR activity in astrocytes suggests that host cell factors modulating HIV expression may differ from those dominant in T-cells or immortalized astroglia, and this could contribute to differences in the astrocyte's ability to support HIV replication.

Astrocytes↗
PubMed1998

The manufacturing process for recombinant factor IX.

Advances in recombinant DNA manufacturing technology have now made possible the production of a highly purified and active recombinant factor IX (rFIX) product. Recombinant factor IX was developed by (1) stable insertion of the genes for both factor IX and PACE-SOL (a truncated, soluble serine protease needed to enhance the capacity of cells to remove the amino-terminal propeptide from rFIX) into Chinese hamster ovary cells; (2) selection of a cell line that was capable of expressing high amounts of active rFIX while growing in bioreactors containing a completely defined culture medium that does not contain blood or plasma products; and (3) inclusion of four independent chromatography steps, none of which require monoclonal antibodies. Furthermore, rFIX has been extensively tested to demonstrate similarity to plasma-derived factor IX and has been shown to be a consistent, high-purity product. For example, a high-specific-activity product (276+/-23 IU/mg) has been consistently produced throughout 65 consecutive batches from five consecutive manufacturing campaigns. Thus, rFIX offers a consistent and high-purity source of factor IX treatment for patients with hemophilia B.

Animals↗
PubMed1998

Can the experience of caring at home affect carers' retrospective evaluation of community care services?

This paper investigates whether informal carers' experience of caring for their dying cancer patients at home affects their retrospective evaluation of the services received by these patients from community nurses, GPs, and the health and social services in general. Analysis was conducted on a sub-sample of the Regional Study of Care for the Dying (RSCD), a retrospective survey of family members and others who knew most about the last year of life of a random sample of people who died in 20 health districts in the UK in 1990. The sub-sample consisted of 1,858 carers of people who died from cancer (ICD, 140-208). The results showed statistically significant associations between carers' satisfaction with community nurses, GPs, and the health and social services in general and their perceptions that caring at home was a rewarding activity, and that their social activities were severely or fairly restricted. Carers' satisfaction with all providers was also more likely to have been reported by those who reported having had no need for more home help. All this suggests the importance of supporting carers to enable them to fulfil their caretaking role and to cope with caring at home. This in turn could lead to an increase in their level of acceptability of the services provided.

Aged↗
PubMed1997

Auxiliary partial orthotopic liver transplantation for acute liver failure.

BACKGROUND/AIMS: Auxiliary partial orthotopic liver transplantation holds potential advantages over conventional orthotopic liver transplantation, but experience with the technique in acute liver failure is limited. METHODS: We describe our initial experience in seven patients (4 men, 3 women; mean age 28, range 14-35 years) with acute liver failure (paracetamol 3, non A-E 2, autoimmune 1, Ecstasy 1) who fulfilled criteria for emergency transplantation. Preoperatively, the median international normalised ratio was seven (range 3.4-15), with a creatinine of 123 microM (51-389 microM) and bilirubin 320 microM (61-572 microM). The reasons for performing an auxiliary transplant were the patients' young age and stable preoperative condition (n = 5), or a significant psychiatric history precluding conventional transplantation (n = 2). RESULTS: All patients received blood group-matched left (n = 2) or right (n = 5) auxiliary grafts. Median duration of surgery was 8.5 h (7.3-10 h), with blood loss of 8.3 litres (4.6-14.6 litres). Post-transplant, the international normalised ratio and aspartate aminotransferase fell progressively in all patients, with median values at day 7 of 1.4 (1.0-2.4) and 108 IU/1 (78-910 IU/1). Three patients died from sepsis within the first postoperative month. At 2 weeks, four of six patients had partial regeneration of the native liver, which became complete in two of the survivors by 1 year. CONCLUSIONS: Although patient selection remains poorly defined, auxiliary partial orthotopic liver transplantation in acute liver failure is technically feasible and, in some patients, allows native liver regeneration and eventual immunosuppression withdrawal.

Acute Disease↗
PubMed1997

The clinical diversity and role of chemotherapy in lymphoproliferative disorder in liver transplant recipients.

BACKGROUND/AIMS: Post-transplant lymphoproliferative disorder is a well-documented complication with an incidence ranging from 2 to 10%, depending on the organ transplanted. Yet despite our increased understanding of the pathophysiology of this disease and the various treatments available, the mortality remains high at 60-80%. We present the clinical and histological features of ten adult liver transplant recipients with post-transplant lymphoproliferative disorder presenting over a 15-year period and review the therapeutic options. METHODS: CD20/CD45RO immunostaining was used for T/B-cell markers; polymerase chain reaction and in-situ hybridisation for Epstein-Barr virus genome detection; kappa/lambda immunostaining and gene rearrangement analysis for clonality. RESULTS: There were six females and four males (age range 24-56) with onset of post-transplant lymphoproliferative disorder-symptoms ranging from 3 to 72 months post transplant. Sites of post-transplant lymphoproliferative disorder included liver (n=4), lymph nodes (n=5), bone marrow (n=2), lungs (n=2), kidneys (n=2), brain, ovaries,: and pancreas (n=1). All lesions were classified as high-grade lymphoma, of B-cell lineage (9 tested); Epstein-Barr virus genome was detected in 7/10 cases. Three tumours were monoclonal; four were polyclonal and three undetermined. Treatment included immunosuppression reduction, antiviral therapy with acyclovir and/or chemotherapy (CHOP or VAPEC-B). Survival times for those patients not treated with chemotherapy were from 9 days to 30 months, whereas those receiving chemotherapy had remission times of 4 to 48 months. CONCLUSIONS: Longer-term remissions can be achieved in patients treated with systemic chemotherapy, although not without morbidity. Clonality assessment is important but treatment decisions should be based primarily on clinical features of progression, as polyclonal tumours can behave as aggressively as monoclonal tumours.

Adult↗
PubMed1997

Awareness of dying: prevalence, causes and consequences.

Analysis of a subset of data from a survey of 3696 relatives, friends and others who knew a sample of people dying in 1990 who lived in 20 areas of the United Kingdom (the Regional Study of Care for the Dying) is reported. Using the typology of awareness contexts developed by Glaser and Strauss [(1965) Awareness of Dying, Aldine, Chicago], the prevalence of different awareness contexts is described and compared with an earlier survey done in 1969. Open awareness of dying, where both the dying person and the respondent knew that the person was dying, is the most prevalent awareness context. This is particularly so in cancer and represents a change since 1969 when closed awareness (where the respondent knows, but the dying person does not) was more common. The characteristics of those dying in open and closed awareness contexts are then compared, suggesting that having cancer, not being mentally confused, having a respondent who knew for some time that the person was dying, and being of higher social class are independently predictive of full open awareness, a condition marked both by knowledge of dying, and a value commitment towards openness. Compared with people in closed awareness, people dying in full awareness are more able to plan their dying careers, so that they and their respondents are more satisfied with the degree of choice over the place of death, they are less likely to die alone, and are more likely to die in their own homes. Additionally, these individuals are more likely to have spoken of their wishes for euthanasia, another indicator of their desire to control the manner and timing of death. If dying from cancer, people in full open awareness are more likely to have received hospice care. It is suggested that underlying these patterns, and in contrast with some other cultures where awareness of dying is seen as less desirable, people dying in Anglophone countries are particularly concerned to maintain control over projects of self-identity. Their approach to death is a reflection of this individualism.

Adult↗