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Biomedical subjects

G Asimakopoulos

Publications and source records attributed to G Asimakopoulos.

36 records · Page 2Linked to original sources
PubMed1999

Lung injury and acute respiratory distress syndrome after cardiopulmonary bypass.

Cardiopulmonary bypass is often followed by pulmonary dysfunction as assessed by measuring the alveolar-arterial oxygenation gradient, intrapulmonary shunt, degree of pulmonary edema, pulmonary compliance, and pulmonary vascular resistance. It is also regarded as a risk factor for development of acute respiratory distress syndrome. On the other hand, cardiopulmonary bypass is associated with a whole body inflammatory response, which involves activation of complement, leukocytes, and endothelial cells with secretion of cytokines, proteases, arachidonic acid metabolites, and oxygen free radicals. Leukocyte adhesion to microvascular endothelium, leukocyte extravasation, and tissue damage are the final steps. Although the inflammatory response to cardiopulmonary bypass often remains at subclinical levels, it can also lead to major organ dysfunction and multiple organ failure. This review article summarizes the recent literature on the molecular and cellular mechanisms involved in the phenomenon of pulmonary dysfunction after cardiopulmonary bypass. It also summarizes reports on the prevalence and mortality of acute respiratory distress syndrome after cardiac surgery.

Cardiopulmonary Bypass↗
PubMed1999

Radical resection of a pulmonary blastoma involving the mediastinum.

Pulmonary blastoma is a rare primary lung tumour associated with poor prognosis. Despite modern diagnostic imaging and biopsy techniques, the diagnosis is usually not considered initially. A case of a 22-year-old man with a large biphasic left-sided pulmonary blastoma, extending to the mediastinum, is reported. It was treated by pneumonectomy and pericardiectomy with radical tumour resection from the anterior mediastinum, under cardiopulmonary bypass. Adjuvant radiotherapy was used. 3 years postoperatively there is no sign of recurring disease.

Adult↗
PubMed1999

Mechanisms of the systemic inflammatory response.

The purpose of inflammation is to combat various agents that may injure the tissues. Conditions such as CPB can often cause systemic inflammation and dysfunction of major organs. Pulmonary, renal, myocardial and intestinal function may suffer various degrees of impairment during and after cardiac surgery. Although changes in major organs usually remain clinically insignificant, severe organ failure is not uncommon. The process of systemic inflammation proceeds through activation of serum proteins, activation of leucocytes and endothelial cells, secretion of cytokines, leucocyte-endothelial cell interaction, leucocyte extravasation and tissue damage. Several anti-inflammatory strategies have already been used, some of which have given promising results pertaining to further reduction in the rate of the inflammation-related complications in cardiac surgical patients.

Cardiopulmonary Bypass↗
PubMed1998

Effects of cardiopulmonary bypass on leukocyte and endothelial adhesion molecules.

During the inflammatory response, triggered by cardiopulmonary bypass, interaction between activated leukocytes, platelets, and endothelial cells is mediated through the expression of three main groups of adhesion molecules: the selectins, the integrins, and the immunoglobulin superfamily. The selectins, which mediate the initial rolling of the leukocyte on the endothelium, are divided in three subgroups: L-selectin is expressed on all three leukocyte types, P-selectin is expressed on platelets and endothelial cells, and E-selectin is only expressed on endothelial cells. Integrins can be found on most cell types, consist of an alpha and a beta subunit and mediate firm adhesion of the leukocyte and migration into the tissues. They are classified into subgroups according to the type of their beta subunit. Immunoglobulins such as ICAM-1 and VCAM-1 are expressed mainly on endothelium and act as ligands for certain integrins. This review article summarizes the existing, and rapidly expanding, literature concerning the effects of cardiopulmonary bypass on the expression of leukocyte and endothelial adhesion molecules. Deeper understanding of the, behavior and the role of adhesion molecules during cardiopulmonary bypass may facilitate effective intervention in the inflammatory response process and suppression of its adverse effects.

Animals↗
PubMed1998

Recognition and management of hypercholesterolaemia in patients awaiting elective coronary artery bypass grafting.

The recently published Scandinavian Simvastatin Survival Study showed that long-term treatment with simvastatin, in patients with ischaemic heart disease and serum cholesterol levels between 5.5 and 8.0 mmol/l, improved survival. The present study was conducted in order to evaluate whether patients with ischaemic heart disease awaiting coronary revascularisation are aware of their serum cholesterol levels and whether raised levels are being treated adequately. One hundred consecutive patients admitted from our waiting list for elective coronary artery bypass grafting, with or without valve replacement, were included in the study. The patients were asked whether they had a history of raised serum cholesterol and, if so, how this was being treated. Fasting serum cholesterol levels were subsequently taken in the morning before surgery. Forty-six patients gave a positive history of raised blood cholesterol levels; 25 of these were on cholesterol-lowering medication at the time of admission, 15 were on a lipid-lowering diet and six were not being treated. Thirty-one (67%) of these 46 patients had a serum cholesterol of more than 5.5 mmol/l, compared with 30 (56%) of the 54 patients without a positive history of hypercholesterolaemia, and 61% of the total 100 patients. These data suggest that an inadequate number of patients awaiting coronary artery bypass grafting are aware of their cholesterol status. The management of hypercholesterolaemia among these patients could be improved.

Adult↗
PubMed1998

'One-stop' rectal bleeding clinics without routine flexible sigmoidoscopy are unsafe.

Over 90% of patients referred to surgeons for investigation of rectal bleeding have haemorrhoids, fissure-in-ano or proctitis. Full investigation of these patients to exclude colonic neoplasia or inflammatory bowel disease imposes a considerable load on a hospital's resources as well as exposing the patient to significant inconvenience and morbidity. A 'one-stop' outpatient clinic was established, with selective use of flexible sigmoidoscopy, based on the judgement and clinical findings of a single experienced surgeon. Over a 4 month period, 344 patients were assessed, and 326 were identified as not needing flexible sigmoidoscopy. At 3 and 6 monthly follow-up, 22 presented with persistent rectal bleeding and three previously unidentified cancers were found on performance of flexible sigmoidoscopy. If a 'one-stop' policy is to be used in the management of rectal bleeding, routine flexible sigmoidoscopy is essential for all patients.

Adult↗
PubMed1998

Pre-admission clinic in an orthopaedic department: evaluation over a 6-month period.

A pre-admission clinic for patients undergoing elective orthopaedic surgery has been used at the Royal Surrey County Hospital, Guildford, for the past 3 years. This report audits the activities of the clinic over a period of 6 months. Data regarding the patients who were invited to the pre-admission clinic during the study period were analysed. In all, 232 patients were asked to attend the clinic and a total of 221 (95.2%) attended. Of these patients, 10 had their operations cancelled and three had their operations postponed in the clinic due to various medical and social reasons. Another 28 operations were cancelled or postponed at a later stage. All of the postponed procedures were eventually performed within 3 months. Of the 232 patients, 180 (77.5%) underwent their operation on the arranged day without any complications. The pre-admission clinic in our orthopaedic department helps us to prevent a significant number of operation cancellations on the day of admission. It also facilitates an extensive pre-operative assessment of the patients and reduces the ward-based workload of the junior medical staff. More extensive use of the pre-admission clinic is recommended.

Adolescent↗
PubMed1997

Aortic valve replacement in patients 80 years of age and older: survival and cause of death based on 1100 cases: collective results from the UK Heart Valve Registry.

BACKGROUND: Aging of the population and advances in preoperative and postoperative care are reflected in an increasing number of patients > or = 80 years of age undergoing aortic valve replacement (AVR) in the United Kingdom. The present study presents data on postoperative 30-day mortality, actuarial survival, and cause of death based on a large collective patient population. METHODS AND RESULTS: Data were extracted from the UK Heart Valve Registry. From January 1986 to December 1995, 1100 patients > or = 80 years of age underwent AVR and were reported to the registry. Six hundred eleven patients (55.5%) were women. The mean follow-up time was 38.9 months. The 30-day mortality was 6.6%. Of the 73 early deaths, 42 were due to cardiac reasons. The actuarial survival was 89%, 79.3%, 68.7%, and 45.8% at 1, 3, 5, and 8 years, respectively. After the first 30 postoperative days, 144 of the 205 deaths were due to noncardiac reasons. Malignancy, stroke, and pneumonia were the most common causes of late death. Bioprosthetic valves were implanted in 969 patients (88%) and mechanical valves in 131 (12%) patients. There was no difference in early mortality and actuarial survival between the two groups (P>.05). CONCLUSIONS: The above results suggest that under the selection criteria for AVR currently applied in the United Kingdom, patients > or = 80 years of age show a satisfactory early postoperative outcome and moderate medium-term survival benefit.

Aged↗
PubMed1997

Survival and cause of death after mitral valve replacement in patients aged 80 years and over: collective results from the UK heart valve registry.

OBJECTIVE: Over the last decade there has been an increasing number of patients aged 80 years and over undergoing heart valve replacement. However, literature on the outcome of mitral valve replacement (MVR) in this age group is still limited. METHODS: We conducted the present study by analysing data extracted from the UK Heart Valve Registry. From January 1986 to December 1994, 86 patients underwent isolated MVR and 10 underwent combined MVR with aortic valve replacement (AVR) and were reported to the Registry. RESULTS: The 30 day mortality was 10.4% (9/86) in the MVR group and 10% (1/10) in the MVR and AVR group. The actuarial survival was 79.8, 64.1 and 40.7% at 1, 3 and 5 years, respectively, in the MVR group. Of the 10 early (30 day) deaths, 8 were due to cardiac reasons and 19 of the 28 late deaths were due to non-cardiac reasons. A total of 55 (57.2%) patients received a bioprosthetic valve implant and 41 (42.8%) patients received a mechanical valve implant. There was no difference in survival between the two groups. CONCLUSIONS: The above results suggest that MVR in octogenarians produces a satisfactory early postoperative outcome and moderate medium-term benefit. There is no difference in survival between patients receiving bioprosthetic and patients receiving mechanical valve implants.

Actuarial Analysis↗
PubMed1995

A regional study of thyroidectomy: surgical pathology suggests scope to improve quality and reduce cost.

This study of thyroid histopathological data from hospitals in the South West Thames region was undertaken to assess current practice and the scope for improvement. Over a 6 month period, 186 thyroid operations were performed on 179 patients at eight hospitals serving almost 1.7 million people. The frequency of thyroidectomy in different hospitals varied from 13 to 35 per 100,000 per year and 6.4% of the operations were second thyroidectomies. Benign multinodular goitre was the most common histological finding (34%). A benign solitary nodule was found in 36% and malignancy in 8.4% of the specimens. Correlation of histological analysis and type of operation suggested that a variety of operations were performed for the same pathological condition and that some operations were diagnostic procedures only. Overall, 63 of the 186 operations (34%) might have been avoided by a firm preoperative diagnosis. Only 67 thyroid fine needle aspiration biopsies (FNAC) were performed at the eight hospitals during the study period. Only 15 (8%) of the patients who underwent thyroid operation had been investigated by FNAC. Reduction in thyroid surgery through more widespread use of FNAC could result in savings of 100,000 pounds per million population per year. Regional activity data show that more than 50 surgeons currently undertake a workload of less than 500 thyroidectomies each year. Increased subspecialisation may be required to reduce costs and raise standards.

Biopsy, Needle↗
PubMed1994

Adjuvant chemotherapy with dacarbazine, vindesine, and cisplatin in pathological stage II malignant melanoma.

Following curative lymph node dissection, 28 patients with pathological Stage II malignant melanoma (metastatic to regional lymph nodes) received adjuvant chemotherapy with dacarbazine, vindesine, and cisplatin (DVP); 32 more patients with similar characteristics refused adjuvant treatment. In the treated group, 15 patients (53%) developed dissemination of disease after 4 to 29 months; 20 (62%) of the patients who refused adjuvant treatment recurred after 4 to 25 months and received palliative treatment with DVP. No significant differences in survival or disease-free survival according to different patient characteristics could be detected between these two groups with the available patient population. Large and well-designed prospective randomized trials are required to determine if the adjuvant use of this treatment schedule, which includes the three most active drugs improves survival in patients with nondisseminated melanoma.

Adult↗
PubMed1987

The diagnostic value of gastrocnemius muscle biopsy in sarcoidosis presenting with erythema nodosum and hilar adenopathy.

Five cases of sarcoidosis were identified among twenty cases of erythema nodosum, admitted to the Department of Medicine, during a two-year period. The clinical picture was dominated by hilar adenopathy and erythema nodosum in all cases. All five patients had gastrocnemius muscle biopsy performed, which revealed noncaseating epithelioid granuloma in four. Diagnosis in the fifth patient was made by transbronchial lung biopsy. The present study suggests, that gastrocnemius muscle biopsy might be considered as the initial diagnostic procedure of choice in this, more commonly seen in Caucasians, syndrome of sarcoidosis, presenting with hilar adenopathy and erythema nodosum, based on its safety, ease of performance and relatively high sensitivity and specificity.

Adolescent↗
PubMed1986

Brucella arthritis.

Nine cases of peripheral arthritis were identified among 40 patients with brucellosis, in the endemic area of Southwestern Greece, during a 4-year prospective study. In 5 patients the joint was aspirated and the examination of the synovial fluid revealed white cell counts ranging from 4,460/mm3 to 8,800/mm3, with lymphocytic predominance. Synovial fluid cultures were positive for Brucella in 3 out of the 5 patients. These findings suggest that brucella arthritis is mainly a true septic arthritis, with characteristic joint fluid features, which distinguish it from other septic arthritides, a fact that is extremely helpful in its early diagnosis and management in an endemic area.

Adult↗
PubMedDate not supplied

Pharmacokinetic interaction in beagle dogs of antiplatelet drugs: acetylsalicylic acid, dipyridamole and calcium dobesilate.

In clinical practice, the co-administration of antiplatelet drugs, such as acetylsalicylic acid (ASA) and dipyridamole (DP) and calcium dobesilate, is often recommended in order to obtain secondary prophylaxis against certain ischaemic diseases. Therefore the possible pharmacokinetic interactions between these three drugs were studied after a single-dose in beagle dogs. The plasma concentrations of ASA, DP and CaDb were measured by HPLC. It was found that the DP and CaDb kinetics were unaffected by concurrent intake of ASA, DP or CaDb. However, concurrent DP or CaDb improved the bioavailability of ASA, particularly the increased Cmax and (AUC).

Administration, Oral↗
PubMedDate not supplied

[Pregnancy and inflammatory bowel disease].

Inflammatory bowel disease (IBD)--Crohn's disease, ulcerative colitis--affects frequently the women in their childbearing years with concerns about both on pregnancy and evolution of the IBD. Important issues concerning a pregnant woman with IBD include the effect of pregnancy on the disease, and, conversely, the effect of IBD on pregnancy and inheritance of IBD in the offspring. Adverse fetal outcomes are not increased when IBD is inactive; however, women with active disease incur a greater risk of premature birth. Most of women with active IBD at the time of contraception have continued or worsening disease activity during pregnancy. Most medications for IBD are safe during pregnancy, with notable exceptions. A key principle of management is that active disease, not therapy, poses the greatest risk to pregnancy.

Colitis, Ulcerative↗