complement ͉ differentiation ͉ surfactant proteins ͉ ␣-1-antitrypsin ͉ cystic fibrosis transmembrane conductance receptor T he alveolar epithelium covers Ͼ99% of the internal surface area of the lung and is composed of two major cell types, the alveolar type I (ATI) cell and the alveolar type II (ATII) cell. ATI cells are large flat cells through which exchange of CO 2 /O 2 takes place. They cover Ϸ95% of the alveolar surface and comprise Ϸ40% of the alveolar epithelium and 8% of the peripheral lung cells. In contrast, ATII cells are small, cuboidal cells that cover Ϸ5% of the alveolar surface and comprise 60% of the alveolar epithelium and 15% of the peripheral lung cells. They are characterized by the unique ability to synthesize and secrete surfactant protein C (SPC) and by the distinct morphological appearance of inclusion bodies, known as lamellar bodies. Important functions of ATII cells are (i) to synthesize, store, and secrete surfactant, which reduces surface tension, preventing collapse of the alveolus; (ii) to transport ions from the alveolar fluid into the interstitium, thereby minimizing alveolar fluid and maximizing gas exchange; (iii) to serve as progenitor cells for ATI cells, which is particularly important during reepithelialization of the alveolus after lung injury; and (iv) to provide pulmonary host defense by synthesizing and secreting several complement proteins including C3 and C5

Oxidative modification of LDL increases its atherogenicity, and 15-lipoxygenase (15-LO) has been implicated in the process. To address this issue, we generated transgenic rabbits that expressed 15-LO in a macrophage-specific manner and studied their susceptibility to atherosclerosis development when they were fed a high-fat, high-cholesterol (HFHC) diet (Teklad 0533 rabbit diet 7009 with 10% corn oil and 0.25% cholesterol) for 13.5 wk. Transgenic and nontransgenic rabbits developed similar degrees of hypercholesterolemia and had similar levels of triglyceride, VLDL, LDL, and HDL. Quantitative morphometric analysis of the aortic atherosclerosis indicated that the transgenic animals ( n ϭ 19) had significantly smaller lesion areas (9.8 Ϯ 6.5%, mean Ϯ SD) than their littermate controls ( n ϭ 14, 17.8 Ϯ 15.0%) ( P Ͻ 0.05). In a subgroup ( n ϭ 9) of transgenic rabbits that received the HFHC diet plus the antioxidant N Ј , N Ј -diphenyl-phenylenediamine (1%), the extent of lesion involvement (9.8 Ϯ 7.5%) did not differ from the subgroup ( n ϭ 10) that received the regular HFHC diet (9.7 Ϯ 5.9%). Since the results were unexpected, we repeated the experiments. Again, we found that the nontransgenic littermates ( n ϭ 12) had more extensive lesions (11.6 Ϯ 10.6%) than the transgenic rabbits ( n ϭ 13; 9.5 Ϯ 7.8%), although the difference was not significant. In a third set of experiments, we crossed 15-LO transgenic rabbits with Watanabe heritable hyperlipidemic (WHHL) rabbits and found that the lesion area in the 15-LO transgenic/heterozygous WHHL rabbits ( n ϭ 14) was only about one third (7.7 Ϯ 5.7%) that found in nontransgenic heterozygous WHHL littermate controls ( n ϭ 11, 20.7 Ϯ 19.4%) ( P Ͻ 0.05). These data suggest that overexpression of 15-LO in monocytes/macrophages protects against lipid deposition in the vessel wall during early atherogenesis in these rabbit models of atherosclerosis. ( J. Clin

PURPOSE: The purpose of this study was to evaluate the use of telemedicine amid the SARS-CoV-2 pandemic in patients with cancer and assess barriers to its implementation. PATIENTS AND METHODS: Telehealth video visits, using the Houston Methodist MyChart platform, were offered to patients with cancer as an alternative to in-person visits. Reasons given by patients who declined to use video visits were documented, and demographic information was collected from all patients. Surveys were used to assess the levels of satisfaction of treating physicians and patients who agreed to video visits. RESULTS: Of 1,762 patients with cancer who were offered telehealth video visits, 1,477 (83.8%) participated. The patients who declined participation were older (67.7 v 60.2 years; P < .0001), lived in significantly lower-income areas ( P = .0021), and were less likely to have commercial insurance ( P < .0001) than patients who participated. Most participating patients (92.6%) were satisfied with telehealth video visits. A majority of physicians (65.2%) were also satisfied with its use, and 74% indicated that they would likely use telemedicine in the future. Primary concerns that physicians had in using this technology were inadequate patient interactions and acquisition of medical data, increased potential for missing significant clinical findings, decreased quality of care, and potential medical liability. CONCLUSION: Oncology/hematology patients and their physicians expressed high levels of satisfaction with the use of telehealth video visits. Despite recent advances in technology, there are still opportunities to improve the equal implementation of telemedicine for the medical care of vulnerable older, low-income, and underinsured patient populations.

We have produced gene knockout mice by targeted disruption of the apobec-1 gene. As recently reported by Hirano et al. (Hirano, K.-I., Young, S. G., Farese, R. V., Jr., Ng, J., Sande, E., Warburton, C., Powell-Braxton, L. M., and Davidson, N. O. (1996) J. Biol. Chem. 271, 9887-9890), these animals do not edit apolipoprotein (apo) B mRNA or produce apoB-48. In this study we have performed a detailed analysis of the lipoprotein phenotypic effects of apobec-1 gene disruption that were not examined in the previous study. We first analyzed the plasma lipoproteins in knockout animals with a wild-type genetic background. Although there was no difference in plasma cholesterol between apobec-1(-/-), +/-, or +/+ mice, there was a marked (176%) increase in plasma apoB-100, from 1.8 +/- 1.2 mg/dl in apobec-1(+/+) mice to 2.7 +/- 0.6 mg/dl in apobec-1(+/-) and 5.0 +/- 1.4 mg/dl in apobec-1(-/-) mice. Plasma apoE was similar in these animals. By fast protein liquid chromatography (FPLC) analysis, there was a significant decrease in plasma high density lipoprotein (HDL) cholesterol in apobec-1(-/-) mice. We further fractionated the plasma lipoproteins into d < 1.006, 1.006-1.02, 1.02-1.05, 1.05-1.08, 1.08-1.10, and 1.10-1.21 g/ml classes, and found a marked (30-40%) reduction in the cholesterol and protein content in the (d 1.08-1.10 and 1.10-1.21) HDL fractions, corroborating the FPLC data. SDS-gel analysis revealed an absence of apoB-48, an increase in apoB-100 in the very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions, and a small decrease in apoA-I in the HDL fractions in the apobec-1(-/-) samples. We next raised the basal plasma apoB levels in the apobec-1(-/-) animals by cross-breeding them with human apoB transgenic (TgB) mice. The plasma apoB-100 was 3-fold higher in apobec-1(-/-)/TgB+/- mice (26.6 +/- 18.3 mg/dl) than in apobec-1(+/+)/TgB+/- mice (9.8 +/- 3.9 mg/dl, p < 0.05). The apobec-1(-/-)/TgB+/- mice had a plasma cholesterol levels of 170 +/- 28 mg/dl and triglyceride levels of 106 +/- 31 mg/dl, which are 80% and 58% higher, respectively, than the corresponding values of 94 +/- 21 mg/dl and 67 +/- 11 mg/dl in apobec+/+/TgB+/- mice. By FPLC, the apobec-1(-/-)/TgB+/- animals developed markedly elevated plasma LDL cholesterol (518.5 +/- 329.5 microg/ml) that is 373% that of apobec1(+/+)/TgB+/- mice (139.0 +/- 87.0 microg/ml) (p < 0.05). The elevated plasma triglyceride was accounted for mainly by a 97% increase in VLDL triglyceride in the apobec1(-/-)/TgB+/- mice. We conclude that apobec-1(-/-) animals have a distinctive lipoprotein phenotype characterized by significant hyperapoB-100 and HDL deficiency in mice with a wild-type genetic background. Furthermore, the abolition of apoB mRNA editing elevates plasma total cholesterol and LDL cholesterol in apobec-1(-/-) animals with a TgB background. Finally, to exclude the possibility that absence of apoB mRNA editing was a secondary effect of chronic Apobec-1 deficiency, we treated apobec-1(-/-) mice with a replication-defective mouse Apobec-...

Current concepts of the biomembrane will be extrapolated to membranes of homeotherms to illustrate the influence of the nature of dietary lipid in nutritionally complete diets on membrane polar head group content and fatty acid composition. Utilizing animal models, the controlling influence of dietary long chain fatty acids on major lipid constituents of the mitochondrial membrane in cardiac tissue, the plasma membrane of liver, and the synaptosomal membrane in brain can be demonstrated. Diet-induced alterations in membrane composition are associated with demonstrable changes in the function of specific membrane proteins. To illustrate this relationship, the effect of diet on mitochondrial ATPase activity and on a hormone receptor-stimulated function in the plasma membrane of the liver will be discussed. These observations suggest that the diet fat modulates enzyme functions in vivo by changing the surrounding lipid environment in the membrane.