What evidence is there for the existence of individual genes with antagonistic pleiotropic effects?

Classical evolutionary theory predicts the existence of genes with antagonistic effects on longevity and various components of early-life fitness. Quantitative genetic studies have provided convincing evidence that such genes exist. However, antagonistic pleiotropic effects have rarely been attributed to individual loci. We examine several classes of longevity-assurance genes: those involved in regulation of the gonad; the insulin-like growth factor pathway; free-radical scavenging; heat shock proteins and apoptosis. We find initial evidence that antagonistic pleiotropic effects are pervasive in each of these classes of genes and in various model systems--although most studies lack explicit studies of fitness components. This is particularly true of human studies. Very little is known about the early-life fitness effects of longevity loci. Given the possible medical importance of such effects we urge their future study.     

Is it safe to use a thermocautery device for circumcision? Examination of the histopathological changes emerging after thermocautery-assisted circumcisions

Multiple number of techniques and devices have been described concerning circumcision method so far. One of them is thermocautery device, and it has been widely used. Although there is controversy that the penis may be damaged due to the heat generated during the use of the device, not enough histopathological studies have been conducted. We aimed to determine the histopathological changes in human foreskin caused by heat after circumcision with thermocautery and to demonstrate the safety of the use of a thermocautery-assisted circumcision. Forty-one patients were divided into two groups according to the thermal energy used during cutting with thermocautery as follows: high temperature (Group 1, n = 22) and low temperature (Group 2, n = 19). The effect of the heat intensity and depth of the coagulation necrosis produced with thermocautery-assisted circumcisions performed at low and high temperatures were evaluated. The difference between the groups was not statistically significant. Tissue damage is extremely limited in thermocautery-assisted circumcisions, even when it is used at high temperatures. The thermocautery device can be used for effective and safe circumcisions.     

Visualization of retinal vasculitis in Eales' disease

Between 1970 and 1991 the authors examined 466 patients with Eales' disease. The mean age at diagnosis was 30, ranging between 14 and 55 years. The mean follow-up period was 43.5 months. At the initial examination, 356 cases were bilateral and 110 cases were unilateral (822 eyes). Vitreous hemorrhage was present in 257 of the 822 eyes. In the remaining 565 eyes, the major retinal lesions were retinal neovascularization (40.7%), vascular sheathing (20.7%), vascular sheathing and retinal hemorrhages (10.6%), retinitis proliferans (9.4%), disc neovascularization (9.0%), branch vein occlusion (3.2%), tractional retinal detachment (2.4%), central vein occlusion (1.8%), central vascular sheathing (1.1%), obliterated vessels (1.1%). Forty-nine out of the 110 initially unilateral cases eventually developed bilateral involvement after a mean period of 42 months. The percentage of eyes with a vision of 0.1 and better rose from 68.1% in the initial examination to 77.9% in the final examination. Fluorescein angiograms of the affected eyes show dye leakage with retinal staining, microaneurysms, capillary non-perfusion and neovascularization. Fundus changes are characteristic of Eales' disease. Unilateral cases should be closely followed because of the risk of involvement of the other eye. Fluorescein angiography is a requirement for early identification of vascular changes and for proper follow-up in Eales' disease.     

Photocoagulation in Eales' disease

Between 1970 and 1991 the authors examined 466 cases with Eales' disease. 359 eyes of 295 of these 466 cases received photocoagulation treatment. The mean age was 30.4, ranging between 14 and 55 years. Ten eyes with persistent vitreous hemorrhage underwent pars plana vitrectomy before photocoagulation. 210 eyes were treated with xenon arc, 135 with argon laser, 12 with krypton laser and two with yellow dye laser. Hypoxic areas and retinal neovascularizations were closed completely in 298 eyes. In 21 eyes with elevated neovascularizations intruding into the vitreous cavity feeder vessel photocoagulation was used. 24 eyes with disc neovascularization were treated with panretinal photocoagulation. 12 eyes with branch vein occlusion and four eyes with central vein occlusion received photocoagulation treatment to areas of non-perfusion and retinal neovascularization. At a mean follow-up of 43 months, seven new retinal neovascularizations and three new disc neovascularizations developed in eyes which previously had received photocoagulation for retinal neovascularization and hypoxia. Nine out of 21 eyes with elevated neovascularizations developed vitreous hemorrhage. Disc neovascularization resolved completely in 13 out of 24 eyes, it partially regressed in eight eyes and did not respond to treatment in three eyes. The visual acuities were improved in 12.3%, maintained in 77.4% and deteriorated in 10.3% of the eyes after treatment. Periodic follow-up and early photocoagulation treatment is useful in stabilizing the retinal lesions and in maintaining functional levels of vision in Eales' disease.     

Early and late visual prognosis in solar retinopathy

Background: Solar retinopathy was observed in a total of 86 eyes of 58 patients following the solar eclipse over Turkey in April 1976. The visual prognosis and the presence of late complications were evaluated at the early and late periods. Methods: Of the 58 patients, 34 (51 eyes) presented during the first week and came for follow-up examination in the succeeding week, also after 1, 3, 12 and 18 months. After that they were examined at yearly intervals (mean 4.2 years). Twenty-four patients (35 eyes) presented during the period between 1 and 11 years post-eclipse and were followed up for a mean period of 3.4 years. After a period of 15 years, all of the patients were invited for re-examination and nine patients (14 eyes) attended. Results: The improvement in visual acuity was observed to have taken place mostly during the first 2 weeks to 1 month after the eclipse. Further improvement in visual acuity was not observed in any of the eyes after the 18-month examination. The improvement in visual acuity was more prominent and earlier in the eyes that had visual acuity of 0.2 or better initially. Only the eyes with initial visual acuity equal to or better than 0.4 had a chance to improve their acuity to 10/10. Having observed the 51 eyes for mean period of 4.2 years and the 35 eyes for 3.4 years, no change in visual acuity was observed. Among the total of 86 eyes, 9 were found to have pseudolamellar macular holes. Conclusion: Correlation was found between initial visual acuity and the funduscopic appearance after the 2nd week. Fluorescein angiography was not found to be a conclusive test in solar retinopathy. No late complications were observed.     

Left atrioventricular valve repair technique in partial atrioventricular septal defects

BACKGROUND: The aim of our study was to evaluate the effect of chordal transfer around the cleft on left atrioventricular valve competence in the late postoperative period. METHODS: Forty-four adult patients underwent surgical correction of partial atrioventricular septal defect between 1983 and 1997. Fenestration was found in 8 patients (18.2%) and cleft, in 35 (79.5%). There was no chordal support of the free edges of the left superior and left inferior leaflets around the cleft in 18 patients. Two chordae were mobilized from the left lateral leaflet and reimplanted into the tip of the left superior and left inferior leaflets around the cleft. RESULTS: At 5 years postoperatively, left atrioventricular valve insufficiency was severe in 5 patients and moderate in 11 patients who had had cleft closure alone. In contrast, severe valvular insufficiency was present in only 1 patient in the group with chordal transfer (p < 0.05). Reoperation was done in 5 patients with isolated cleft closure. Left AV valve replacement was performed in 1 patient. CONCLUSIONS: Chordal transfer plus cleft closure with interrupted sutures significantly reduces early and late left atrioventricular valve incompetence and also decreases the rate of reoperation.     

The effects of dexamethasone and levobupivacaine on postoperative pain in Modified Radiofrequency Assisted Uvulopalatoplasty (MRAUP) surgery

The objective of this prospective, randomized study was to evaluate the effect of pre-emptive local infiltration of lidocaine, lidocaine plus dexamethasone, levobupivacaine and levobupivacaine plus dexamethasone on postoperative pain in Modified Radiofrequency Assisted Uvulopalatoplasty (MRAUP) cases. Sixty adult patients (44 males and 16 females) aged 32–51 years with simple snoring were divided into four groups. The anesthesia of the patients in the first group was achieved with lidocaine HCl, in the second group, with lidocaine HCl and dexamethasone sodium phosphate, in the third group, with levobupivacaine, and in the fourth group, levobupivacaine and dexamethasone sodium phosphate. All the patients were applied Modified Radiofrequency Assisted Uvulopalatoplasty technique. The pain experienced by the patients during swallowing and at rest on the 1st, 3rd, 5th, 7th, and 10th day and analgesic consumption were evaluated using standard 10 cm visual analog scales. The mean duration of operation in the group that received lidocaine HCl was 22 ± 3 min, while in the group that received levobupivacaine HCl was 27 ± 4 min. There were statistically significant differences between the groups for analgesic effects on the 1st, 3rd, 5th, and 7th day and for the amount of analgesics used, on the 1st, 3rd, and 5th day. The best results were obtained in the group that received levobupivacaine HCl and steroid (p < 0.001). Steroid and local anesthetic combinations are superior to controls in the management of postoperative pain in MRAUP surgery.