Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output?

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26-43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from -20 to -191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.

Effects of antiplatelet therapy with indobufen or aspirin-dipyridamole on graft patency one year after coronary artery bypass grafting.

Saphenous vein coronary artery bypass graft patency can be increased by antiplatelet therapy. Aspirin plus dipyridamole are effective but are associated with tolerability problems. Indobufen is a possible alternative antiplatelet agent that may be better tolerated. A prospective, randomized, double-blind, parallel-group study was undertaken to compare the efficacy and safety of indobufen 200 mg twice daily with aspirin 300 mg thrice daily plus dipyridamole 75 mg thrice daily in preventing occlusion of autologous saphenous vein coronary artery bypass grafts. A total of 803 patients were randomized in the study, of whom 552 had a follow-up coronary angiogram approximately 1 year after operation. All anastomoses were patent in 56% of indobufen-treated patients and 59% of aspirin-dipyridamole recipients (p = 0.384). The percentage of all anastomoses patent was 82% in the indobufen group and 83% in the aspirin-dipyridamole group (p = 0.297). Mean postoperative blood loss was significantly less in the indobufen group (p = 0.043). Patients who received indobufen also had significantly fewer adverse events considered to be treatment-related compared with aspirin-dipyridamole recipients (p = 0.02). At the doses tested indobufen was as effective as aspirin plus dipyridamole in preventing occlusion of saphenous vein grafts and was better tolerated. Because indobufen was associated with less postoperative blood loss it may be used before operation in coronary artery bypass grafting.

Early pulmonary vein thrombosis after single lung transplantation.

Pulmonary venous obstruction after single lung transplantation may be mistaken for reperfusion injury or myocardial dysfunction. Complete obstruction of one of the major pulmonary veins will result in hemorrhagic infarction of the affected lobe within 4 to 6 hours, limiting the option of treatment to resection (lobectomy) or retransplantation. Early diagnosis is therefore essential. Transesophageal echocardiography can show the pulmonary venous anastomosis and, combined with color flow and Doppler imaging, offer a quick and reliable method of diagnosis. Prevention of this complication entails harvesting an adequate margin of left atrial tissue around the pulmonary vein orifices, meticulous surgical anastomosis, and the use of anticoagulation in the presence of a thrombogenic tendency in the recipient.

Coronary ostial stenosis: surgical considerations.

To investigate the clinical significance of coronary ostial stenosis, we reviewed eight patients with such lesions, including three with isolated stenosis at the orifice of the coronary artery. There were five male and three female patients, with an average age of 46.25 years (range 32-69 years). Their symptoms consisted mainly of angina (6 patients), with dyspnoea and palpitation being the presenting features in the remaining two patients. All patients underwent preoperative coronary angiography which confirmed stenosis at the level of the orifice with absence of reflux of contrast medium into the sinus of Valsalva as the main features. Delay in the appreciation of stenosis of the orifice of the right coronary artery resulted in the death of two patients, whose diagnosis was confirmed at post mortem examinations. Stenosis of the orifice of the right coronary artery was present in seven patients, with two patients also having stenosis of the orifice of the left coronary artery. The remaining patient had isolated stenosis of the left coronary arterial orifice. Coronary artery bypass grafting was performed in five patients, including two who had patch angioplasty to the right coronary artery. The patient with isolated stenosis of the orifice of the left coronary artery had patch angioplasty only. Follow-up of up to three years in the surviving patients showed good functional results. The ease with which it is possible to miss right coronary ostial stenosis is emphasized and angiographic features are reviewed.

Surgical implications of anomalous aortic origin of the left coronary artery.

We report a patient with exertional chest pain and anomalous aortic origin of the left coronary artery from the right coronary sinus. This patient also had circumflex coronary and right coronary artery stenoses. Following coronary bypass grafting of the circumflex and right coronary arteries in this patient, angina persisted and there was abnormal septal perfusion shown on the exercise thallium imaging despite patent grafts. The angina and perfusion defect were improved by bypass grafting of the unstenosed left anterior descending coronary artery in this patient. Thallium imaging may be useful in the preoperative assessment of patients with this anomaly.

Echocardiographic diagnosis of quadricuspid aortic valve.

Isolated quadricuspid aortic valve is very rare. The identification of this malformation can be made by cross-sectional echocardiography. Two cases of quadricuspid aortic valve diagnosed by cross-sectional echocardiography are described.

Internal mammary artery conduit: an additional surgical procedure in difficult coarctation of the aorta.

Between October 1986 and February 1987 two young men with coarctation of the aorta and a hypoplastic isthmus were treated by a combined resection and isthmusplasty with implantation of the left internal mammary artery to the distal aorta. An appreciable drop in the systolic gradient was seen in both patients after the mammary artery anastomosis and haemodynamic variables across the repair continued to improve postoperatively. Digital transvenous subtraction angiography five months after operation showed a satisfactory mammary artery conduit across the repaired coarctation.

Incidence of thyroid disease in cases of hypertrophic cardiomyopathy.

The investigative findings of patients considered to have possible hypertrophic cardiomyopathy were examined, and 31 of these fulfilling defined criteria for the disease were reviewed in detail, with emphasis on thyroid abnormalities. Four patients had a history of thyroid disease (13%). Explanations considered for the apparent association were the effects of hyperthyroidism on normal, or more probably, incipiently abnormal myocardium.

Crohn's disease of the stomach and duodenum.

Clinical and radiological abnormalities in 12 patients with gastroduodenal involvement were encountered amongst 300 patients followed by one of us between 1944 and 1969. Symptoms of dyspepsia were relatively mild and obstructive symptoms when present were readily relieved by bypass surgery. The patients have been followed for a mean of 9.7 years (range 1-20); two have died of other causes but the remaining 10 are well.

Mitral valve prolapse: an assessment of clinical features, associated conditions and prognosis.

One hundred and eighty-two patients (100 females, 82 males) with mitral valve prolapse (MVP) confirmed by echocardiography are described. Their ages range from 12 to 87 years (mean 48 years). The symptoms of breathlessness, pain in the chest and palpitations were analysed. They were associated with left ventricular failure, co-existing ischaemic heart disease and arrhythmias in some, but in a proportion the symptoms were thought to be due to psychoneurosis. Seventy-two patients (40 per cent) were referred because of complications of MVP. In 67 patients (37 per cent) the condition was discovered by chance and in 43 patients (24 per cent) neurotic symptoms had led to referral to hospital. A systolic click was heard in 117 patients (54 per cent); 41 patients (23 per cent) had a late systolic murmur and 30 patients (16 per cent) had a pansystolic murmur. The incidence of murmurs rose with increasing age, and pansystolic murmurs were more frequent in males. Thirty-two patients (18 per cent) had neither a click nor a murmur. Twenty-four patients (13 per cent) had associated supraventricular tachycardia and 22 (12 per cent) atrial fibrillation. Twelve patients (7 per cent) had severe mitral incompetence and eight (4 per cent) developed bacterial endocarditis. Only three patients had symptoms suggesting cerebral ischaemia. Twelve patients (7 per cent) had associated aortic incompetence. Twenty-two patients had had an inguinal hernia, the incidence in males over 50 being 26 per cent. Twenty-six patients (14 per cent) had non-specific T wave changes in the electrocardiogram. Echocardiography showed that 112 patients (62 per cent) had mid-systolic buckling of the posterior leaflet and 70 patients (38 per cent) had holosystolic prolapse. In view of the high incidence of complications it is felt that the long-term prognosis not as good as has been generally believed.

Angina, coronary risk factors and coronary artery disease in patients with valvular disease. A prospective study.

The relationship between coronary risk factors and coronary artery disease in patients with valvular heart disease was studied prospectively in 387 consecutive patients undergoing routine coronary arteriography prior to valve replacement. Coronary artery disease was as common in patients with mitral valve disease (31.9%) as in those with aortic valve disease (26.8%). Although it occurs more frequently in patients with angina (45.7%) significant coronary artery disease is found in 19.2% (47 of 245) of those without angina (P less than 0.001), suggesting that the presence of angina alone is an unreliable indicator of significant coronary disease. The prevalence and severity of significant coronary artery disease increases progressively as the number of coronary risk factors also increase (P less than 0.001) but the prevalence is low (3%) in patients in whom both angina and coronary risk factors are absent. These findings suggest that preoperative coronary arteriography might be omitted in this latter group of patients.

Smoking and coronary artery disease assessed by routine coronary arteriography.

The association between extent and duration of smoking habit and severity of coronary atheroma was examined in 387 patients undergoing routine coronary ateriography before valve replacement surgery. Total number of cigarettes smoked in life correlated significantly with severity of coronary artery disease (p less than 0.001) and number of coronary arteries with stenoses of 50% or more (p less than 0.001). Severity of coronary artery disease in current smokers was similar to that in former smokers. Multiple regression analysis showed diastolic blood pressure, cigarette consumption, age, ratio of total cholesterol to high density lipoprotein cholesterol, and history of angina to be the important predictors of severity of coronary artery disease. An estimate of the number of cigarettes smoked in life can be useful in identifying patients with coronary artery disease if used in conjunction with data on other important risk factors.

Preoperative prediction of significant coronary artery disease in patients with valvular heart disease.

A prognostic index for predicting significant coronary artery disease was established using multiple logistic regression analysis of clinical data from 643 patients with valvular heart disease who had undergone routine coronary arteriography before valve replacement. The index or equation obtained incorporated the presence of angina, a family history of ischaemic heart disease, age, cigarette smoking habits, mitral valve disease, sex, and electrocardiographic evidence of myocardial infarction. The equation was validated using prospective data from 387 patients with valvular disease and shown to enable almost a third of routine coronary arteriograms to be omitted while maintaining 95% sensitivity for patients with coronary artery disease. Similar analysis of the more detailed prospective data produced a second discriminant function incorporating diastolic blood pressure, total cigarettes smoked in life, the severity of angina, family history of ischaemic heart disease, age, current cigarette smoking habits, and the ratio of total to high density lipoprotein cholesterol. This method improved the discrimination between patients with and without coronary artery disease, allowing omission of 30% of routine coronary arteriograms with 100% sensitivity for patients with coronary disease and omission of 41% with a 96% sensitivity level.