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Biomedical subjects

M J Boyle

Publications and source records attributed to M J Boyle.

At least 37 records · Page 2Linked to original sources
PubMed1995

Expression of cytokine genes in T cell leukemias.

Normal T cells secrete cytokines which have important effects on a wide range of other cells. In the present study, the expression of IL-2, IL-4, IL-5, IL-10 and IFN-gamma was assessed in PBMC from 3 cases of T cell leukemia, using reverse transcription and polymerase chain reaction (RT-PCR). The major difference between the leukemia cases and control PBMC samples was that, without in vitro stimulation, IFN-gamma was much more readily detected in 2 of the leukemia cases. IL-2 and IL-5 mRNA were also detected in 2 of the patients but not in the other samples. IL-4 mRNA was not detected in any unstimulated sample, whereas IL-10 was always present. After polyclonal stimulation in vitro, mRNA for all these cytokines was detected in all samples. Thus cytokine expression, particularly of IFN-gamma, may be more prominent in PBMC from adult T cell leukemia cases than in controls.

Adult↗
PubMed1995

Accuracy of duplex versus angiography in patients undergoing carotid surgery.

The operative findings of 23 carotid arteries were compared with pre-operative duplex scans and angiography. Both duplex and angiography had a high degree of accuracy in detecting haemodynamically significant lesions of 50-99% (88 and 92%, respectively). Their accuracy, however, in correctly predicting the grade of stenosis was significantly lower; 30 and 48%, respectively (P < 0.001). They each exhibited an accuracy of 70% and 78%, respectively, in the detection of ulceration. Overall, both duplex and angiography displayed an accuracy of 87% in indicating the proper management course. The combination of both investigations increased this accuracy to 94.6%. In severely stenotic lesions, duplex to rule out occlusion was not reliable. On statistical analysis, there was no difference between duplex and angiography in predicting haemodynamically significant lesions of 50-99%, estimating the grade of stenosis, the detection of ulceration, or indicating the proper management course. In most situations, duplex alone equalled the accuracy of angiography in the pre-operative assessment of patients for carotid surgery. For stenotic lesions of > 90%, however, we recommend supplemental angiography to rule out occlusion.

Carotid Arteries↗
PubMed1994

Blood serum levels of PCDFs and PCBs in Yu-Cheng children peri-natally exposed to a toxic rice oil.

Children secondarily exposed through their mothers to a toxic rice oil containing PCDFs and PCBs in the Yu-cheng incident have shown developmental delay even a decade after the incident. Forty-five serum samples were collected from these children in February 1991 ad small amounts analyzed for their contaminant content using sample enrichment and isotope dilution mass spectrometry. In about one-half the samples, detectable levels of PCDFs and PCBs could still be determined with average values for 2, 3, 4, 7, 8-PnCDF and 1, 2, 3, 4, 7, 8-HxCDF of 300 and 620 ng/kg serum lipid, respectively. The mean of the total PCBs on a whole weight basis was 7.5 micrograms/kg. These concentrations of PCDFs and PCBs are still 10 to 25 times higher than those from a matched control population. Although the serum levels did not correlate with developmental delays, those for the two PCDFs but not the total PCBs correlated with duration of breast feeding indicative of postnatal exposure. The results of this study suggest that estimation of past prenatal exposure of children to PCDFs is best carried out using current mother and not current child blood concentrations.

Adult↗
PubMed1994

The effect of heated wire circuits on humidification of inspired gases.

We performed this study to determine the effect of heated wire circuits on humidity delivered by several humidifiers commonly used during anesthesia. Humidifier bases from three manufacturers with several humidifying chambers for each base were tested using both heated and unheated circuits. Delivered humidity and circuit temperature were measured at the distal end of the circuit. Each chamber was tested under both continuous flow (CF) and intermittent flow (IF) conditions. IF was provided by a Servo 900 B ventilator. Adjustments of flow and volume were made for pediatric chambers. At 90 L/m CF, humidifier performance was unsatisfactory with both heated and unheated circuits. At 15 and 45 L/m CF, both distal circuit temperature (DCT) and humidity were within acceptable limits; unheated circuits delivered more humidity than heated circuits (P < 0.05). Relative humidity was lower at 45 L/m CF than at 15 L/m (P < 0.05). During IF while all chambers provided satisfactory humidity, humidity was greater when unheated circuits were used. We conclude that when heated circuits are used, humidifying systems may fail to deliver 100% humidity to patients.

Adult↗
PubMed1993

Subtypes of Epstein-Barr virus (EBV) in Hodgkin's disease: association between B-type EBV and immunocompromise.

Epstein-Barr virus (EBV) has been associated with Hodgkin's disease (HD) in up to 50% of cases, but the subtype of EBV involved has only recently been studied. In this report, biopsy samples from 30 patients with HD were assessed for EBV sequences using both the polymerase chain reaction (PCR) and in situ hybridization (ISH). EBV sequences were localized to the malignant Reed-Sternberg cells and their mononuclear variants (Hodgkin's cells) in 9 of the 30 cases, with 7 demonstrating A-type and 2 B-type EBV sequences. Both of the patients with B-type EBV-associated HD had features to suggest pre-existing immune compromise: one was infected with human immunodeficiency virus (HIV) and had severe CD4+ T-lymphocyte depletion; the other was a debilitated elderly patient with dementia. A previous study suggested that A-type EBV alone is associated with HD and the finding of predominantly A-type EBV in the present series is in keeping with this report. The presence of B-type EBV in the HD of patients with pre-existing immunodeficiency, taken together with the recent report that B-type EBV occurs in HIV-associated non-Hodgkin's lymphoma, suggests that B-type EBV may be an important human pathogen in immunocompromised patients.

Actins↗
PubMed1993

HIV seroconversion illness.

HIV seroconversion is associated with characteristic clinical findings which reflect the first interaction of HIV with the host immune system. Recognition of the characteristic clinical illness associated with HIV seroconversion helps to establish an early diagnosis and obviates the need for further investigation or empiric therapy. It may also afford a unique opportunity to institute counselling to prevent the further spread of HIV in the community.

Adult↗
PubMed1993

15 AU81, a prostacyclin analog, potentiates immunosuppression and mitigates renal injury due to cyclosporine.

15 AU81, a synthetic prostacyclin analog, inhibits human mixed lymphocyte culture responses in a dose-dependent manner at concentrations within a range [0.1 to 10.0 micrograms/ml] similar to that of cyclosporine, methylprednisolone, antilymphocyte serum, and prostaglandin E1 and E2 analogs. Using the median-effect analysis to dissect immunosuppressive interactions, 15 AU81 and cyclosporine were shown to produce synergistic effects on human peripheral blood lymphocyte activation upon phytohemagglutinin or anti-CD3 monoclonal antibody stimulation. In vivo, 15 AU81 potentiated the effect of cyclosporine to prolong the survival of rabbit renal allografts using concentrations of each agent that were individually ineffective. Furthermore, addition of 15 AU81 mitigated functional damage of rabbit kidneys due to high-dose cyclosporine therapy. These observations suggest that the addition of 15 AU81 may broaden the therapeutic window of cyclosporine by potentiating immunosuppression and mitigating nephrotoxic effects.

Animals↗
PubMed1993

Increased expression of interferon-gamma in hyperplastic lymph nodes from HIV-infected patients.

Polyclonal B cell activation is characteristic of HIV infection and occurs in the presence of severe CD4+ lymphocyte depletion. In contrast, CD4+ lymphocytes are the dominant T cell in the reactive lymphoid tissues of patients not infected with HIV. In this study, lymph node biopsies from eight HIV-infected patients with persistent generalized lymphadenopathy syndrome (PGL) were assessed for IL-1 beta, IL-2, IL-4, IL-6, IL-10, interferon-gamma (IFN-gamma) and tumour necrosis factor-beta (TNF-beta) gene expression using the polymerase chain reaction (PCR). The cytokine gene expression of two cases of reactive adenopathy in patients not infected with HIV was assessed for comparison. IFN-gamma was expressed much more strongly in the PGL samples than in control reactive lymphoid tissues, whereas the other cytokines were expressed to a similar extent in both types of tissues. IFN-gamma may have an important role in maintaining the adenopathy of HIV-infected patients. Expression of cytokines such as IL-2, IL-4 and IL-10 in HIV nodes may be adequate to allow the recruitment of naive B cells to the reactive process.

AIDS-Related Complex↗
PubMed1993

The role of Epstein-Barr virus subtypes in human immunodeficiency virus-associated lymphoma.

High grade B cell non-Hodgkin's lymphoma (NHL) is an increasingly important problem in individuals infected with the human immunodeficiency virus (HIV). Fifty percent of these tumours harbour the Epstein-Barr virus (EBV) and there is an equal frequency of EBV A and B-subtypes in the tumours. This contrasts with the recent report that only A-type EBV is associated with Hodgkin's disease. Such studies are challenging the traditional models of EBV-associated lymphomagenesis and showing the way for further studies in this field. This article reviews the studies of EBV subtypes in HIV-associated NHL and uses this new knowledge to discuss the role of EBV in lymphomagenesis.

Antigens, Viral↗
PubMed1993

HIV and malignancy.

Although a number of tumors in patients infected with the human immunodeficiency virus have been reported, Kaposi's sarcoma and non-Hodgkin's lymphoma remain the two principal malignancies. This article provides an Australian perspective of the recent advances in research into malignancy in HIV-infected persons.

Australia↗
PubMed1992

Epstein-Barr virus and HIV play no direct role in persistent generalized lymphadenopathy syndrome.

Persistent generalized lymphadenopathy (PGL) and polyclonal B cell activation are features of infection with HIV. Epstein-Barr virus (EBV) and HIV are known to activate B cells in vitro, but whether they are important B cell activators in patients infected with HIV is less clear. In this study, lymph node tissue was obtained from 10 patients with PGL and assessed for evidence of EBV and HIV gene sequences. DNA was extracted and specific viral gene sequences identified using the polymerase chain reaction (PCR). EBV sequences were difficult to detect in the PGL tissue, with a signal intensity similar to that of other benign and malignant lymphoid conditions not associated with EBV. HIV sequences were also rare in the PGL tissue, consistent with HIV infection of the small number of peripheral blood cells and nodal T cells likely to be present in such a sample. These findings suggest that the polyclonal B cell activation typical of HIV is not driven by direct EBV or HIV infection of B cells.

AIDS-Related Complex↗
PubMed1992

Presence of single-stranded DNA in PCR products of slow electrophoretic mobility.

PCR products were characterized by electrophoresis, blotting and hybridization. In addition to the bands of expected size, bands of slower electrophoretic mobility were often detected. The slower bands completely disappeared when the PCR products were subjected to slow cooling, treated with S1 nuclease or run on an alkaline gel, whereas the bands of expected size were unaffected. The slower bands are therefore likely to contain single-stranded DNA.

Base Sequence↗
PubMed1991

Subtypes of Epstein-Barr virus in human immunodeficiency virus-associated non-Hodgkin lymphoma.

Biopsy samples obtained from 20 patients with human immunodeficiency virus (HIV)-associated non-Hodgkin lymphoma (NHL) were assessed for evidence of Epstein-Barr virus (EBV) and HIV sequences. DNA was extracted from formalin-fixed, paraffin-embedded NHL tissue and specific viral gene sequences were sought using the polymerase chain reaction (PCR). EBV sequences were found in 10 NHL samples (50%), with five tumors showing A-type and five B-type sequences. By serologic testing, 18 of 19 patients had antibodies to EBV, with 14 patients having antibodies to A-type EBV and 11 to B-type EBV. Serology confirmed the high prevalence of type B EBV in HIV-infected patients, but was not a reliable indicator of the EBV subtype present in the lymphomas. HIV sequences were present in biopsy tissue but at a level consistent with an origin from bystander HIV-infected cells. All 20 patients were negative by enzyme-linked immunosorbent assay for antibodies to human T-cell leukemia virus-type I. The high prevalence of type B EBV in these tumors is similar to the findings in endemic Burkitt's lymphoma, where 40% of the tumors have type B viral sequences. In normal populations, type B EBV is rarely found outside the nasopharynx. These studies support the hypothesis that EBV is an important cofactor in NHL in HIV-infected persons. The finding that B-type EBV is present in 25% of HIV-associated NHL suggests that this EBV subtype may be an important human pathogen with a wider geographic distribution than originally thought.

Antigens, Viral↗
PubMed1991

Sulphadiazine desensitization in patients with AIDS and cerebral toxoplasmosis.

The objectives of this study were to evaluate the efficacy of a sulphadiazine desensitization protocol to treat patients with AIDS and cerebral toxoplasmosis (CT) and known sulphonamide allergy, to ensure that an adequate dose of sulphadiazine (2-4 g/day) was achieved rapidly (within 4-5 days), and to assess the effect of concurrent corticosteroid (CS) administration on the success rate of the regimen. Sixteen patients with CT and a past history or current manifestations of sulphonamide allergy were desensitized to sulphadiazine from October 1988 to December 1989. The protocol employed the oral administration of gradually increasing increments of sulphadiazine 3-hourly over 5 days. Success was defined as tolerance of 2-4 g oral sulphadiazine per day for at least 7 days until death or the present time without any allergic reactions. Our success rated overall was 10 out of 16 patients (62%). Seven patients achieved a final dose of 4 g/day and three a dose of 2 g/day. Concurrent CS administration did not appear to affect the outcome in the small number of patients studied. Our sulphadiazine regimen rapidly, successfully and safely desensitized patients with CT and sulphonamide allergy, allowing the optimal first-line treatment to continue. The aetiology of allergy in HIV-infected patients and the mechanisms by which desensitization works are unknown.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Modular indirect calorimeter suitable for long-term measurements in multipatient intensive care units.

OBJECTIVE: The construction of an indirect calorimeter capable of long-term automated sequential monitoring of multiple patients in adult and pediatric ICUs. DESIGN: A prototype system utilizing modular engineering principles, including central respiratory mass spectrometer; validation by organic solvent combustion and nitrogen dilution methods, and Tissot spirometer. SETTING: Surgical and pediatric ICUs in a tertiary care university hospital. RESULTS: When expired minute volume was measured over a range of 4 to 28 L in six intubated patients, expired minute volume measured by the prototype system demonstrated a correlation coefficient of .998 compared with simultaneous expired minute volume measured by a Tissot spirometer. Organic solvent combustion demonstrated a maximum error of 3.8% for oxygen consumption (VO2) and an average error of 1.73 +/- 1.25% (SEM). The maximum error for the respiratory quotient was 3.0%, with an average error of 1.75 +/- 1.07%. VO2 (predicted) vs. VO2 (measured) demonstrated a correlation coefficient of .997. Validation with the nitrogen dilution method over a range of FIO2 from 0.21 to 0.60 demonstrated a maximum error of 7.9%, with an average error of -1.72 +/- 1.1% (n = 51). CONCLUSIONS: Indirect calorimetry by means of a shared system for measurements in multiple patients in ICUs is feasible and cost effective utilizing modular principles and a centralized respiratory gas analyzer.

Adult↗
PubMed1991

Role of drugs and alcohol in patients with head injury.

In an effort to define the role that substance abuse has to play in head injuries, a prospective study of 204 patients presenting to the Accident and Emergency (A&E) Department over a 10-week period was carried out. Urine samples were collected and assayed for the presence of common drugs of abuse and alcohol. One or other substance (drugs or alcohol) was detected in 43% of patients. The association between alcohol and head injuries has been confirmed and the importance of drugs in this area has been addressed and found to be of some significance. More rapid and accurate methods of assaying these substances may improve our management of head injury patients.

Alcohol Drinking↗