Biomedical subjects

A Tierney

Publications and source records attributed to A Tierney.

At least 19 recordsLinked to original sources

PubMed1995

Timing of repair of congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation support.

Treatment of congenital diaphragmatic hernia (CDH) has undergone a revolutionary change in philosophy, from previous urgent repair to the present practice of stabilization and delayed repair. However, when extracorporeal membrane oxygenation (ECMO) is required, many people believe that the risk of postoperative pulmonary hypertension (PPHN) mandates hernia repair while on ECMO. This report details the experience in two ECMO centers with stabilization, ECMO if required, and CDH repair post-ECMO. All CDH patients symptomatic in the first hour of life with a gestational age of at least 34 weeks during the period were reviewed retrospectively. Standard criteria were used to select patients for ECMO. High-frequency jet or oscillating ventilators and nitric oxide were not routinely available throughout the study period, but were used in some of the more recent patients. A total of 60 patients presented to the two centers; 24 cases were stabilized with conventional management, repair of the CDH was done elective, and survival was 100%. Eight patients were referred after having repair elsewhere; six survived (75%). The two deaths were attributable to associated lethal lesions--complex cyanotic heart disease and alveolar capillary dysplasia. Eight patients who required ECMO were managed with the intention of repairing the defect on ECMO. Four survived (50%). Two patients died before repair. Twenty patients were managed with ECMO, with the intention of repairing the defect after decannulation. Overall survival was 13 (65%), deaths were caused by pre-ECMO hypoxia, pulmonary insufficiency, and associated cardiac disease. No patient had recurrent pulmonary hypertension after late repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Capillaries↗

PubMed1995

Fetal response to carbon dioxide pneumoperitoneum in the pregnant ewe.

OBJECTIVE: To determine the effects of maternal abdominal carbon dioxide (CO2) insufflation on placental blood flow and fetal blood gas measurements in the pregnant ewe. METHOD: Five time-bred ewes at 110 days' gestation were surgically prepared with maternal and fetal catheters placed for subsequent measurement of vascular pressures, blood gas tensions, and placental blood flows. On surgical recovery day 3, the ewe was anesthetized, placed on her right side, intubated, and manually ventilated to maintain a constant maternal carbon dioxide pressure (PCO2) range (37.1 +/- 3.3 mmHg) for the duration of the experiment. The maternal abdomen was inflated with CO2 to maintain an intraabdominal pressure of 20.7 +/- 0.6 mmHg. Maternal and fetal blood flows and blood gases were determined at 30 minutes of ventilation, 60 minutes of insufflation, and 40 minutes of desufflation. Simultaneous maternal and fetal organ blood flows were determined using the radioactive microsphere technique. RESULTS: Maternal perfusion pressure fell 22% (P = .01) in response to insufflation, whereas pressure in the inferior vena cava rose 53% (P = .003). Maternal placental blood flow fell to 61% (P = .002) of control. Seventy-seven percent of this blood-flow change was in response to the decreased perfusion pressure, with 23% resulting from an increased placental vascular resistance of 32% (P = .02). Maternal blood gas values did not change with insufflation or desufflation. Despite the marked decrease in maternal placental blood flow, the fetal placental perfusion pressure and blood flow, pH, and blood gas tensions were unaffected by insufflation or desufflation. CONCLUSION: The sheep fetus has sufficient placental flow reserves or compensatory responses to maintain adequate gas exchange during a 1-hour, 20 mmHg maternal pneumoperitoneum. Laparoscopic surgical procedures may prove to be a safe alternative to laparotomy during pregnancy.

Animals↗

PubMed1993

Purchasing palliative care: availability and cost implications.

This paper reports on a survey of the availability of palliative care in Scotland, in the context of the internal market introduced as part of the NHS reforms. It is based on a survey of both the cost and availability of such service, with a discussion of the implications of this information for purchasers of palliative care.

Data Collection↗

PubMed1992

Neurological melioidosis: seven cases from the Northern Territory of Australia.

Pseudomonas pseudomallei, which causes melioidosis, is most commonly associated with pulmonary infection. We describe seven patients who developed a neurological syndrome as the predominant manifestation of melioidosis: this syndrome was characterized by peripheral motor weakness (mimicking Guillain-Barré syndrome), brain-stem encephalitis, aseptic meningitis, and respiratory failure. Neurological melioidosis occurred in the absence of demonstrable foci of infection in the central nervous system (CNS) in five of six patients whose cerebrospinal fluid was available for culture. Computed tomography and magnetic resonance imaging of the brain and spinal cord of these patients were not suggestive of pyogenic infection, although the latter procedure detected brain-stem encephalitis. Autopsy findings in one case confirmed brain-stem encephalitis without evidence of direct bacterial infection. The clinical presentation of neurological melioidosis includes features of an exotoxin-induced neurological syndrome, with profound neurological disease occurring in the absence of apparent direct infection of the CNS. This syndrome appears to be a newly recognized clinical presentation of melioidosis.

Adult↗

PubMed1991

Circulating interferon-alpha levels and hypertriglyceridemia in the acquired immunodeficiency syndrome.

PURPOSE: The metabolic disturbances seen during infection are thought to be due to cytokines, modulators of the immune response. The acquired immunodeficiency syndrome (AIDS) is characterized by a high prevalence of hypertriglyceridemia and at times depletion of body cell mass (wasting). Elevated circulating levels of cytokines have also been reported in AIDS. Therefore, we determined the relationship between circulating cytokine levels and lipid levels and between circulating cytokine levels and wasting in AIDS and human immunodeficiency virus (HIV) infection. PATIENTS AND METHODS: Serum samples from 45 patients with AIDS, 13 subjects with evidence of HIV infection by presence of antibody but without AIDS (HIV positive), and 17 seronegative control subjects who had previously undergone body composition analysis were analyzed for triglyceride, cholesterol, interferon, tumor necrosis factor (TNF), and interleukin-1 levels. Eleven subjects with AIDS or HIV infection had sequential measurements. Interferon was analyzed by bioassay with identification using specific antibodies. TNF and interleukin-1 were assayed by enzyme-linked immunosorbent assay. Lean body mass was assessed by total body potassium. RESULTS: Serum interferon-alpha levels were significantly elevated in patients with AIDS (p less than 0.001 compared to controls), with detectable levels in 84% of AIDS patients. Interferon-alpha was not detectable in serum from controls, while three of 13 HIV-positive subjects had detectable interferon-alpha levels. There was a significant correlation between interferon-alpha levels and serum triglyceride levels in AIDS and HIV-positive patients (R = 0.446, p less than 0.002). There was no relationship between interferon-alpha and serum cholesterol levels (R = -0.039, NS). In contrast only 11% of AIDS patients had detectable circulating TNF levels; the mean value for and the prevalence of detectable serum TNF levels were not significantly different from those of control subjects. Interleukin-1 was not detected in the circulation. There was no correlation between the presence of circulating TNF and serum triglycerides. There was no relationship between circulating interferon-alpha or TNF levels and the presence of wasting as measured by total body potassium. CONCLUSION: These studies suggest that interferon-alpha, which has previously been shown to modulate lipid metabolism in vivo and in vitro, may be responsible for the hypertriglyceridemia found in AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Remediation of cognitive deficits in schizophrenia.

Studies have suggested that schizophrenia is characterized by an impairment in the dorsolateral prefrontal cortex that prevents learning of some elementary information processing tasks. To test this hypothesis, the authors administered the Wisconsin Card Sorting Test to 16 schizophrenic inpatients with standard instructions and either contingent or noncontingent reinforcement. Performance was markedly impaired under each condition. A second cohort (N = 12) was tested after receiving instructions plus rehearsal and feedback. These subjects' performance was comparable to nonpatient norms and was maintained on a subsequent day. The results indicate that deficits in performance on the Wisconsin Card Sorting Test are remediable, whether or not they are due to neurological impairment.

Adult↗

PubMed1989

Hypertriglyceridemia in the acquired immunodeficiency syndrome.

PURPOSE: A relationship between the induction of hypertriglyceridemia by cytokines and the cachexia seen in chronic infection has been proposed by other investigators. Since patients with the acquired immunodeficiency syndrome (AIDS) often experience progressive tissue wasting, we decided to examine serum lipid levels and body cell mass in patients with AIDS. PATIENTS AND METHODS: Serum lipid levels and body cell mass were measured in 32 patients with the acquired immunodeficiency syndrome (AIDS), eight asymptomatic subjects who were anti-human immunodeficiency virus (HIV) antibody positive, and 17 heterosexual and homosexual control subjects who did not have antibodies to HIV. RESULTS: Mean triglyceride concentrations and the prevalence of hypertriglyceridemia (50 percent) were significantly increased in patients with AIDS compared with control subjects (p less than 0.002 and p less than 0.005, respectively), whereas the mean triglyceride levels of HIV-positive subjects were intermediate. There were no differences in cholesterol levels among the three groups. Using total body potassium adjusted for height and age (KHT) as a measure of body cell mass, 16 of 32 patients with AIDS but none of the HIV-positive or control subjects had significant depletion of body cell mass. There was no direct relationship between triglyceride levels and KHT among AIDS or HIV-positive subjects. In patients with AIDS, mean triglyceride levels and the prevalence of hypertriglyceridemia were similar in the presence and absence of wasting. CONCLUSION: Hypertriglyceridemia is a common finding in AIDS and is independent of the degree of wasting.

Acquired Immunodeficiency Syndrome↗

PubMed1989

Detection of HIV-1 RNA in the lamina propria of patients with AIDS and gastrointestinal disease.

Thirty formaldehyde-fixed, paraffin-embedded endoscopic biopsy specimens from the colon and rectum of 25 patients with acquired immunodeficiency syndrome were examined using a [35S]HIV-RNA in situ hybridization procedure. Nine of the specimens contained cells that bound significant amounts of probe. Cells were considered positive if more than 50 grains of silver (over background) per 200 micron 2 were seen over cells that did not stain with eosin. Most of the positive cells resembled macrophages, although cells with condensed nuclei resembling lymphocytes were found. No epithelial cells expressing viral RNA were detected. Formaldehyde-fixed eosinophils gave spurious signals that could be reduced with sulfhydryl modifying agents. HIV-1 may be disseminated in the lamina propria of the gut at low concentrations in some patients but may not be detectable in others. The lower gut lining may be both a portal of initial infection with HIV and a target of disseminated HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMed1983