PubMed Health⌕ Search

Biomedical subjects

A MacIntyre

Publications and source records attributed to A MacIntyre.

17 recordsLinked to original sources
PubMed2003

Chlamydia pneumoniae infection promotes the transmigration of monocytes through human brain endothelial cells.

We have investigated the effects of Chlamydia pneumoniae on human brain endothelial cells (HBMECs) and human monocytes as a mechanism for breaching the blood-brain barrier (BBB) in Alzheimer's disease (AD). HBMECs and peripheral blood monocytes may be key components in controlling the entry of C. pneumoniae into the human brain. Our results indicate that C. pneumoniae infects blood vessels and monocytes in AD brain tissues compared with normal brain tissue. C. pneumoniae infection stimulates transendothelial entry of monocytes through HBMECs. This entry is facilitated by the up-regulation of VCAM-1 and ICAM-1 on HBMECs and a corresponding increase of LFA-1, VLA-4, and MAC-1 on monocytes. C. pneumoniae infection in HBMECs and THP-1 monocytes up-regulates monocyte transmigration threefold in an in vitro brain endothelial monolayer. In this way, C. pneumoniae infection in these cell types may contribute to increased monocyte migration and promote inflammation within the CNS resulting from infection at the level of the vasculature. Thus, infection at the level of the vasculature may be a key initiating factor in the pathogenesis of neurodegenerative diseases such as sporadic AD.

Alzheimer Disease↗
PubMed1998

Accuracy of the clinical diagnoses of Lewy body disease, Parkinson disease, and dementia with Lewy bodies: a clinicopathologic study.

BACKGROUND: Whether Parkinson disease (PD) and dementia with Lewy bodies (DLB) represent 2 distinct nosologic entities or are diverse phenotypes of Lewy body disease is subject to debate. OBJECTIVES: To determine the accuracy of the diagnoses of Lewy body disease, PD, and DLB by validating the clinical diagnoses of 6 neurologists with the neuropathologic findings and to identify early predictors of the diagnoses. METHODS: Six raters who were unaware of the neuropathologic diagnoses analyzed 105 clinical vignettes corresponding to 29 cases of Lewy body disease (post hoc analysis of 15 patients with PD and 14 with DLB) and 76 patients without PD or DLB whose cases were confirmed through autopsy findings. MAIN OUTCOME MEASURES: Sensitivity and positive predictive value (PPV) were chosen as validity measures and the K statistic as a reliability measure. RESULTS: Interrater reliability for the diagnoses of Lewy body disease and PD was moderate for the first visit and substantial for the last, whereas agreement for diagnosis of DLB was fair for the first visit and slight for the last. Median sensitivity for diagnosis of Lewy body disease was 56.9% for the first visit and 67.2% for the last; median PPV was 60.0% and 77.4%, respectively. Median sensitivity for the diagnosis of PD was 73.3% for the first visit and 80.0% for the last; median PPV was 45.9% and 64.1%, respectively. Median sensitivity for the diagnosis of DLB was 17.8% for the first visit and 28.6% for the last; median PPV was 75.0% for the first visit and 55.8% for the last. The raters' results were similar to those of the primary neurologists. Several features differentiated PD from DLB, predicted each disorder, and could be used as clinical pointers. CONCLUSIONS: The low PPV with relatively high sensitivity for the diagnosis of PD suggests overdiagnosis. Conversely, the extremely low sensitivity for the diagnosis of DLB suggests underdiagnosis. Although the case mix included in the study may not reflect the frequency of these disorders in practice, limiting the clinical applicability of the validity measures, the raters' results were similar to those of the primary neurologists who were not exposed to such limitations. Overall, our study confirms features suggested to predict these disorders, except for the early presence of postural imbalance, which is not indicative of either disorder.

Adult↗
PubMed1996

Perioperative ischaemia in aortic surgery: combined epidural/general anaesthesia and epidural analgesia vs general anaesthesia and i.v. analgesia.

PURPOSE: The goal of this randomized study was to determine whether combined general and epidural anaesthesia with postoperative epidural analgesia, compared with general anaesthesia and postoperative intravenous analgesia, reduced the incidence of perioperative myocardial ischaemia in patients undergoing elective aortic surgery. METHOD: Patients were randomly assigned to one of two groups. One group (EPI, n = 48) received combined general and epidural anaesthesia and postoperative epidural analgesia for 48 hrs. The other group (GA, n = 51) received general anaesthesia followed by postoperative intravenous analgesia. Anaesthetic goals were to maintain haemodynamic stability (+/- 20% of preoperative values), and a stroke volume > 1 ml.kg-1. A Holter monitor was attached to each patient the day before surgery. Leads 11, V2, and V5 were monitored. Myocardial ischaemia was defined as ST segment depression > 1 mm measured at 80 millisec beyond the J point or an elevation of 2 mm 60 millisec beyond the J point which lasted > 60 sec. An event that lasted > 60 sec but returned to the baseline for > 60 sec and then recurred, was counted as two separate events. The Holter tapes were reviewed by a cardiologist blind to the patient's group. RESULTS: There were no demographic differences between the two groups. Myocardial ischaemia was common; it occurred in 55% of patients. In hospital, preoperative ischaemia was uncommon (GA = 3, EPI = 8). Intraoperative ischaemia was common (GA = 18, EPI = 25). Mesenteric traction produced the largest number of ischaemic (GA = 11, EPI = 11) events. Postoperative ischaemia was most common on the day of surgery. Termination of epidural analgesia produced a burst of ischaemia (60 events in 9 patients). CONCLUSION: Combined general and epidural anaesthesia and postoperative epidural analgesia do not reduce the incidence of myocardial ischaemia or morbidity compared with general anaesthesia and postoperative intravenous analgesia.

Aged↗
PubMed1993

Effects of surgery on the generation of lymphokine-activated killer cells in patients with breast cancer.

Natural killer (NK) cell activity and the capacity to generate lymphokine-activated killer (LAK) cell activity were studied in 43 patients with operable breast cancer before and after surgery. Results were compared with those from ten healthy subjects. Patients with breast cancer had normal LAK and NK cell activity before surgery. A subgroup of patients with stage III disease had depressed LAK cell activity (P < 0.013). NK cell activity decreased by over 50 per cent on the first day after surgery and did not return to preoperative levels by day 7 (P < 0.0005). Generation of LAK cell activity was unaffected by surgery. The addition of 10 per cent autologous plasma to the culture medium during the induction of LAK cell activity in vitro did not suppress LAK cell activity in patients with breast cancer. These results suggest that perioperative adjuvant immunotherapy based on interleukin 2 and LAK cells is not ruled out by systemic suppressive effects from either cancer or surgery.

Adult↗
PubMed1991

Abdominal aortic aneurysm repair in a patient with a cardiac transplant.

We describe successful elective abdominal aneurysm repair in a patient with a cardiac transplant. In light of the unique physiology and pharmacology of the denervated heart, this presented an unusual combination of complex problems. Whereas the normally innervated heart increases cardiac output via neural stimuli, the denervated heart relies primarily on the Frank Starling mechanism which is dependent on preload and myocardial contractility. Thus, rapidly changing haemodynamic variables associated with aortic cross-clamping require scrupulous attention to the maintenance of adequate preload as well as myocardial function which can only be manipulated by direct-acting agents. We conclude that the denervated heart will readily compensate for the haemodynamic changes brought about by infrarenal aortic crossclamping if a high-normal preload is maintained and if the transplanted donor heart is free of pathology with good inherent myocardial contractility.

Aorta, Abdominal↗
PubMed1990

A steroid/thyroid hormone receptor superfamily member in Drosophila melanogaster that shares extensive sequence similarity with a mammalian homologue.

A gene in Drosophila melanogaster that maps cytologically to 2C1-3 on the distal portion of the X-chromosome encodes a member of the steroid/thyroid hormone receptor superfamily. The gene was isolated from an embryonic cDNA library using an oligonucleotide probe that specifies the consensus amino acid sequence in the DNA-binding domain of several human receptors. The conceptual amino acid sequence of 2C reveals at least four regions of homology that are shared with all identified vertebrate receptors. Region I includes the two cysteine-cysteine zinc fingers that comprise a DNA-binding domain which typifies all members of the superfamily. In addition, three regions (Regions II-IV) in the carboxy-terminal portion of the protein that encode the putative hormone-binding domain of the 2C gene product resemble similar sequences in vertebrate steroid/thyroid hormone receptors. The similarity suggests that this Drosophila receptor possesses many of the regulatory functions attributed to these regions in vertebrate counterparts. A portion of Region II also resembles part of the human c-jun oncoprotein's leucine zipper, which in turn, has been demonstrated to be the heterodimerization site between the jun and fos oncoproteins. The 2C receptor-like protein most resembles the mouse H2RII binding protein, a member of the superfamily which has been implicated in the regulation of major histocompatibility complex (MHC) class I gene expression. These two gene products are 83% identical in the DNA-binding domain and 50% identical in the putative hormone-binding domain, although no ligand has been identified for either protein. The high degree of similarity in the hormone-binding domain between the 2C protein and the H2RII binding protein outside regions II-IV suggests specific functional roles which are not shared by other members of the superfamily.

Amino Acid Sequence↗
PubMed1986

Salicylate and acetaminophen in donated blood.

Blood donors in Canada are asked to volunteer their history of drug ingestion within the previous 24 hours. The authors analysed 400 serum samples from blood donors for acetylsalicylic acid (ASA) and acetaminophen, two commonly used nonprescription drugs. Although 16 of the samples contained ASA and 10 acetaminophen (2 contained both drugs), none of the donors had volunteered that they had ingested those medications before donating blood. The possible role of these drugs in some of the unexplained reactions to transfusions is considered.

Acetaminophen↗