Heritability of interests: a twin study

The authors administered inventories of vocational and recreational interests and talents to 924 pairs of twins who had been reared together and to 92 pairs separated in infancy and reared apart. Factor analysis of all 291 items yielded 39 identifiable factors and 11 superfactors. The data indicated that about 50% of interests variance (about two thirds of the stable variance) was associated with genetic variation. The authors show that heritability can be conservatively estimated from the within-pair correlations of adult monozygotic twins reared together. Evidence for nonadditive genetic effects on interests may explain why heritability estimates based on family studies are so much lower. The authors propose a model in which precursor traits of aptitude and personality, in part genetically determined, guide the development of interests through the mechanisms of gene-environment correlation and interaction.     

Coronary angioplasty volume-outcome relationships for hospitals and cardiologists

OBJECTIVE: To assess the relationship between each of 2 provider volume measures (annual hospital volume and annual cardiologist volume) for percutaneous transluminal coronary angioplasty (PTCA) and 2 outcomes of PTCA (in-hospital mortality and same-stay coronary artery bypass graft [CABG] surgery). DESIGN: Cohort study, using data from January 1, 1991, through December 31, 1994, from the Coronary Angioplasty Reporting System of the New York State Department of Health. SETTING: Thirty-one hospitals in New York State in which PTCA was performed during 1991-1994. PATIENTS: All 62670 patients discharged after undergoing PTCA in these hospitals during 1991-1994. MAIN OUTCOME MEASURES: Rates of in-hospital mortality and CABG surgery during the same stay as the PTCA. RESULTS: The overall in-hospital mortality rate for patients undergoing PTCA in New York during 1991-1994 was 0.90%, and the same-stay CABG surgery rate was 3.43%. Patients undergoing PTCA in hospitals with annual PTCA volumes less than 600 experienced a significantly higher risk-adjusted in-hospital mortality rate of 0.96% (95% confidence interval [CI], 0.91%-1.01%) and risk-adjusted same-stay CABG surgery rate of 3.92% (95% CI, 3.76%-4.08%). Patients undergoing PTCA by cardiologists with annual PTCA volumes less than 75 had mortality rates of 1.03% (95% CI, 0.91%-1.17%) and same-stay CABG surgery rates of 3.93% (95% CI, 3.65%-4.24%); both of these rates were also significantly higher than the rates for all patients. Also, same-stay CABG surgery rates for patients undergoing PTCA in hospitals with annual volumes of 600 to 999 performed by cardiologists with annual volumes of 75 to 174 (2.99%; 95% CI, 2.69%-3.31 %) and 175 or more (2.84%; 95% CI, 2.57%-3.14%) were significantly lower than the overall statewide rate (3.43%). CONCLUSIONS: In New York State, both hospital PTCA volume and cardiologist PTCA volume are significantly inversely related to in-hospital mortality rate and same-stay CABG surgery rate for patients undergoing PTCA.     

Use of of the high frequency capsulotomy instrument in cataract surgery--effect of coagulation on corneal endothelium

Intumescent or hypermature cataracts make a safe capsulorhexis impossible. High frequency capsulotomy represents a satisfying solution for this problem. Primary goal of the present study was to investigate a possible damage to the corneal endothelium by this method. MATERIALS AND METHODS: 55 patients with an uncomplicated senile cataract were enclosed into a prospective randomized study undergoing cataract surgery with capsulorhexis or with high frequency capsulotomy. Corneal endothelium was examined preoperatively as well as postoperatively at several intervals. RESULTS: Concerning loss of endothelial cells and parameters of polymegatism and pleomorphism there were no statistically significant differences between both groups. CONCLUSION: The diathermy during high frequency capsulotomy does not show any clinically relevant negative effects on the corneal endothelium within cataract surgery.     

The effectiveness of topical anesthesia and vibration in alleviating the pain of oral injections

Low cardiac output was corrected by catecholamines in the course of hemofiltration (HF) administered to 37 patients with multiple organ failure after surgery. Catecholamines (adrenaline hydrochloride, noradrenaline hydrotartrate, dopamine hydrochloride, and dobutamine hydrochloride) were used as monotherapy or in various combinations (two, three, or four drugs). Ninety percent of patients with low cardiac output subjected to HF were administered combined catecholamine therapy. Catecholamines provided the hemodynamic stability of HF in patients with low cardiac output. The frequency of noradrenaline administrations and its mean doses were reliably decreased in the course of HF, whereas the mean doses of adrenaline, dopamine, and dobutamine remained virtually the same.     

ER membrane protein complex required for nuclear fusion

Diploid cells of the yeast Saccharomyces cerevisiae form after the mating of two haploid cells of the opposite mating type. After fusion of the two plasma membranes of the mating cells, a dinucleated cell forms initially in which the two haploid nuclei then rapidly fuse to form a single diploid nucleus. This latter event, called karyogamy, can be divided into two distinct steps: the microtubule-based movement that causes the two nuclei to become closely juxtaposed and the fusion of the nuclear membranes. For the membrane fusion step, one required component, the ER luminal protein Kar2p (BiP), has been identified. For topological reasons, however, it has been unclear how Kar2p could function in this role. Kar2p is localized to the luminal (i.e., noncytoplasmic) face of the ER membrane, yet nuclear fusion must initiate from the cytosolic side of the outer nuclear membrane or the ER membrane with which it is contiguous. There is both genetic and biochemical evidence that Kar2p interacts with Sec63p, an ER membrane protein containing both luminal and cytosolic domains that is involved in protein translocation across the membrane. We have isolated novel sec63 mutant alleles that display severe karyogamy defects. Disruption of the genes encoding other Sec63p-associated proteins (Sec71p and Sec72p) also results in karyogamy defects. A suppressor mutant (sos1-1) partially corrects the translocation defect but does not alleviate the karyogamy defect. sec61 and sec62 mutant alleles that cause similar or more severe protein translocation defects show no karyogamy defects. Taken together, these results suggest a direct role for Sec63p, Sec71p, and Sec72p in nuclear membrane fusion and argue against the alternative interpretation that the karyogamy defects result as an indirect consequence of the impaired membrane translocation of another component(s) required for the process. We propose that an ER/nuclear membrane protein complex composed of Sec63p, Sec71p, and Sec72p plays a central role in mediating nuclear membrane fusion and requires ER luminally associated Kar2p for its function.     

Apolipoprotein E epsilon4 allele as a genetic risk factor for left ventricular failure in homozygous beta-thalassemia

In homozygous beta-thalassemia, the organ damage is mainly attributed to excessive iron deposition through the formation of oxygen free radicals. Despite appropriate transfusion and chelation therapy and low ferritin levels, patients still develop organ failure, heart failure being the main cause of death. This study was designed to determine whether the decreased antioxidant activity of the apolipoprotein E (APOE) 4 allele could represent a genetic risk factor for the development of left ventricular failure (LVF) in beta-thalassemia homozygotes. A total of 251 Greek beta-thalassemia homozygotes were studied. Patients were divided in three groups: group A (n = 151) with no cardiac impairment, group C (n = 47) with LVF, and 53 patients with LV dilatation and normal LV systolic function constituted the group B. DNA was obtained from all patients, and the polymerase chain reaction was used to analyze the polymorphism at the APOE locus. The APOE allele frequencies were compared with those of a Greek control sample of 216 healthy blood donors. Patients with no cardiac impairment had an APOE 4 allele frequency (7.9%) not different from population controls (6.5%, P > .05), while patients with LVF had a significantly higher frequency of APOE 4 (12.8%) than the controls (P < .05, odds ratio = 2.11, 95% confidence interval 1.03 to 4.32). The APOE 4 allele may represent an important genetic risk factor for the development of organ damage in homozygous beta-thalassemia.