Treatment of myocardial ischemia and myocardial infarction in the elderly

The diagnosis of coronary artery disease in the elderly is problematic because older patients often present atypical symptoms or are asymptomatic. Once coronary disease is diagnosed, the proper course of treatment is not always clear, since few studies have focused on patients older than 65 years. Moreover, older patients often have medical conditions that may aggravate coexisting cardiovascular problems or interfere with conventional pharmacotherapy. For these reasons many physicians who treat cardiovascular problems aggressively in younger patients are reluctant to do so in older individuals. There is considerable evidence, however, that older patients could benefit as much or more from aggressive therapy because of their greater risk of mortality from myocardial ischemia and infarction.     

Herbal medicine for the treatment of cardiovascular disease: clinical considerations

Herbs have been used as medical treatments since the beginning of civilization and some derivatives (eg, aspirin, reserpine, and digitalis) have become mainstays of human pharmacotherapy. For cardiovascular diseases, herbal treatments have been used in patients with congestive heart failure, systolic hypertension, angina pectoris, atherosclerosis, cerebral insufficiency, venous insufficiency, and arrhythmia. However, many herbal remedies used today have not undergone careful scientific assessment, and some have the potential to cause serious toxic effects and major drug-to-drug interactions. With the high prevalence of herbal use in the United States today, clinicians must inquire about such health practices for cardiac disease and be informed about the potential for benefit and harm. Continuing research is necessary to elucidate the pharmacological activities of the many herbal remedies now being used to treat cardiovascular diseases.     

Designability, aggregation propensity and duplication of disease-associated proteins

Over 2000 proteins in the Ensembl human genome database have been linked with disease information from OMIM. In comparison with all human proteins, we find that disease-associated proteins tend to have less designable folds in terms of their SCOP family counts, suggesting that they are intrinsically less robust to mutation and environmental stress. Disease proteins also tend to have isoelectric points closer to neutrality and more alternating hydrophilic-hydrophobic amino acid stretches compared with the average human protein. These results suggest that protein aggregation is a significant phenomenon associated with diseases. Another finding in this work is that many disease proteins are highly sequence similar to other disease proteins, suggesting that gene duplication has contributed to the expansion of disease-prone protein families.     

Use of angiotensin-converting enzyme inhibitors as monotherapy and in combination with diuretics and calcium channel blockers

This study presents results on sleep maturation during the first two years of life, based on a longitudinal study of 15 normal children recorded at home over 24 hours at the ages of 3, 6, 9, 12, 18 and 24 months. The development of the different stages and parameters of sleep was studied in quantitative, structural and circadian terms. To do so, various analyses were performed on the polygraphic recording data interpreted using the "adult" criteria suggested by Rechtschaffen et Kales in 1968. Results show the very early presence of some adult sleep parameters, such as the stable mean duration of episodes of paradoxical sleep (PS), the rapid decrease in the amount of this sleep stage, which reaches adult levels by the age of 9 months, the large amount of slow wave sleep in the first sleep cycle from the age of 3 months and the stability of the acrophase of the PS circadian rhythm. The position of the acrophase corresponds to the period of high PS density at the end of the night in adults. Other parameters, such as the increase in stages 1 and 2 of slow wave sleep, the increase in the latency of PS with disappearance at 9 months of PS onset, and the increase in stability of sleep with a decrease in nocturnal waking and body movements, are related to the maturation of the central nervous system structures implicated in the mechanisms of sleep (maturation of the thalamo-cortical pathways and the rostro-caudal pons-thalamus connections). These maturation processes may be markedly influenced by the environment. Finally, the increase with age in the amplitude of the sleep circadian rhythm may lead to both lengthening of the sleep cycle at the age of 12 months and development of the homeostatic process of sleep analysed by temporal changes in slow wave sleep.     

Pressure and gas composition effects on the operation of the pulsed flame photometric detector

The effect of pressure and hydrogen/oxygen ratio of a burning gas mixture on pulsed flame emission time-dependence was investigated in the range of 0.1–5 atm using a specially designed pulsed flame photometric detector (PFPD). We studied the pressure and gas composition effect on the pulsed flame delayed light emission of sulfur, phosphorus, and nitrogen-containing organic compounds. The optimal pressure conditions for nitrogen detection, intensity, and emission time delay was found to be 0.4 bar, at which the detection sensitivity could be improved by a factor of 2. For phosphorus, the optimal pressure obtained was 1.3 bar with 40% sensitivity improvement (compared with 1 bar). In the case of sulfur detection, two emission maxima were obtained, at 1.1 and 0.6 bar, at H/O ratio of 5. Increasing the H/O ratio resulted in the appearance of only one peak at 1 bar, and enhancement of the sensitivity by a factor of 2.4 at H/O ratio of 10.3. From the analytical point of view, we found that emission intensity is practically unchanged by the pressure and the H/O ratio for all three elements investigated in the range of 0.8–1.1 bar and H/O of 5–6. Thus, in addition to excellent sensitivity and improved selectivity, the PFPD can be applied under a variety of atmospheric pressure conditions in field environmental applications.     

Unicornuate uterus: imaging appearance, associated anomalies, and clinical implications

OBJECTIVE: The study is a prospective comparison of helical CT with nonhelical CT arterial portography (CTAP) in the detection of liver metastases from colorectal carcinoma, using surgical and histologic findings as the gold standard. SUBJECTS AND METHODS: Thirty-five patients with colorectal carcinoma and suspected liver metastases were prospectively examined with helical CT and CTAP before surgery. In nine cases, surgery was not performed. In the remaining 26 patients, imaging results were correlated with surgical and pathologic findings. Three radiologists prospectively assessed metastatic involvement with both techniques. The results were compared with pathologic and surgical findings on a lesion-by-lesion basis. In a second phase, three radiologists not directly concerned in the design of the study independently assessed metastatic involvement of the liver as revealed on helical CT and CTAP on a segment-by-segment basis with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: The results of the histologic study disclosed 50 metastatic lesions. Helical CT had a sensitivity of 76% (38/50) and a positive predictive value of 90%. CTAP had a sensitivity of 74% (37/50) and positive predictive value of 69%. Receiver operating characteristic analysis revealed a greater area under the curve (Az index), 0.96, for helical CT than for CTAP (0.86). Differences were statistically significant (p < .001). CONCLUSION: Helical CT is superior to nonhelical CTAP in the detection of hepatic metastases from colorectal carcinoma.     

Cardiac involvement in HIV infection

Cardiac involvement in HIV infection was previously believed to be an unusual manifestation of the disease, but is now being described with increasing frequency. It may be a well-characterized cardiac disease occurring coincidentally in an AIDS patient, a complication of AIDS or its treatment, or possibly a direct result of HIV infection of the heart. In this article, the authors describe the emerging patterns of heart and vascular diseases in HIV-infected patients, pathogenic mechanisms, and implications for treatment.     

Effects of Microstructure on Eddy Current Residual Stress Characterization of Shot-Peened Inconel 718

Recent studies have shown the possibility of exploiting the eddy current (EC) method for nondestructive characterization of near-surface residual stresses in surface-treated nickel-base superalloy components. The method involves measuring swept frequency EC signals to obtain near-surface electrical conductivity depth profiles, which can be converted into residual stress profiles using the empirical piezoresistivity relationship. However, the relationship between EC responses and residual stress profiles appears to depend on the microstructure. This paper reports on a systematic study of microstructural effects on the EC responses and near-surface conductivity deviation profiles induced by shot peening, using a series of heat-treated Inconel 718 samples with different secondary phase contents and thus a variety of hardness levels. Calibrated EC signals from 100 kHz to 50 MHz were measured from aged and unaged samples, before and after shot peening at various Almen intensities. Strong dependence of the EC responses on the sample hardness and microstructure has been observed. A procedure is introduced to convert the EC signals into shot-peening-induced conductivity deviation profiles where the microstructure dependency is suppressed. The resulting estimates of the conductivity changes are larger than expected, indicating that characterization of shot-peening-induced residual stresses by EC requires further understanding of the material responses beyond the empirical piezoresistivity relationship. Other mechanisms that could contribute to the observed conductivity changes are discussed.     

Dispersion of a heavy admixture in a two-phase jet

The article presents experimental data on the distribution of finely-divided powder in the cross sections of a turbulent axisymmetric jet and a qualitative analysis of the experimental data, and the possibility of their generalization is shown.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 18, No. 3, pp. 538–541, March, 1970.