1
|
Tailoring the aluminum nanocrystal surface oxide for all-aluminum-based antenna-reactor plasmonic photocatalysts. Proc Natl Acad Sci U S A 2024; 121:e2321852121. [PMID: 38442156 PMCID: PMC10945844 DOI: 10.1073/pnas.2321852121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 01/24/2024] [Indexed: 03/07/2024] Open
Abstract
Aluminum nanocrystals (AlNCs) are of increasing interest as sustainable, earth-abundant nanoparticles for visible wavelength plasmonics and as versatile nanoantennas for energy-efficient plasmonic photocatalysis. Here, we show that annealing AlNCs under various gases and thermal conditions induces substantial, systematic changes in their surface oxide, modifying crystalline phase, surface morphology, density, and defect type and concentration. Tailoring the surface oxide properties enables AlNCs to function as all-aluminum-based antenna-reactor plasmonic photocatalysts, with the modified surface oxides providing varying reactivities and selectivities for several chemical reactions.
Collapse
|
2
|
Phase transition of individual anatase TiO 2 microcrystals with large percentage of (001) facets: a Raman mapping and SEM study. Phys Chem Chem Phys 2023; 25:3199-3210. [PMID: 36625155 DOI: 10.1039/d2cp04882e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
TiO2 has been extensively studied in many fields including photocatalysis, electrochemistry, optics, etc. Understanding the mechanism of the anatase-rutile phase transition (ART) process is critical for the design of TiO2-based high-activity photocatalysts and tuning its properties for other applications. In this work, the ART process using individual anatase micro-particles with a large percentage of (001) facets was monitored and studied. Phase concentration evolution obtained via Raman microscopy was correlated with the morphological evolution observed in scanning electron microscope (SEM) images. The ART of anatase microcrystals is dominated by surface nucleation and growth, but the ART processes of individual anatase particles are distinctive and depend on the various rutile nucleation sites. Two types of transformation pathways are observed. In one type of ART pathway, the rutile phase nucleated at a corner of an anatase microcrystal and grew in one direction along the edge of the crystal firstly followed by propagation over the rest of the microcrystal in the orthogonal direction on the surface and to the bulk of the crystal. The kinetics of the ART follows the first-order model with two distinct rate constants. The fast reaction rate is from the surface nucleation and growth, and the slow rate is from the bulk nucleation and growth. In the other type of ART pathway, multiple rutile nucleation sites formed simultaneously on different edges and corners of the microcrystal. The rutile phase spread over the whole crystal from these nucleation sites with a small contribution of bulk nucleation. Our study on the ART of individual micro-sized crystals bridges the material gap between bulk crystals and nano-sized TiO2 particles. The anatase/rutile co-existing particle will provide a perfect platform to study the synergistic effect between the anatase phase and the rutile phase in their catalytic performances.
Collapse
|
3
|
A reliability study using Network Oriented Research Assistant (NORA ® ) examining the use of digital photographs in the assessment of psoriasis. Br J Dermatol 2019; 181:214-215. [PMID: 30703265 DOI: 10.1111/bjd.17702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
Ambrisentan for sarcoidosis associated pulmonary hypertension. SARCOIDOSIS, VASCULITIS, AND DIFFUSE LUNG DISEASES : OFFICIAL JOURNAL OF WASOG 2011; 28:139-145. [PMID: 22117505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Sarcoidosis associated pulmonary hypertension (SAPH) is associated with significant morbidity and mortality. There is a paucity of information concerning therapy for this condition. METHODS We performed a prospective, open-label, proof of concept trial of ambrisentan for SAPH. 21 subjects with SAPH received 5 mg/day of ambrisentan for 4 weeks and then 10/mg day for 20 subsequent weeks. RESULTS No significant change was noted in the 6-minute walk distance over the course of the study (mean change between week 0 and 24: 9.8 +/- 54.6 meters, p: NS). There were also no significant differences between weeks 0 and 24 in terms of dyspnea as measured by the modified Borg scale, serum brain naturetic peptide, diffusing capacity, and quality of life as measured by the Short Form-36. There was a high dropout rate: overall: 11/21, 52%; social reasons: 3/21, 14%; medical reasons: 8/21, 38% because of dyspnea: 6/21, 29% and/or edema: 4/21, 19%. Of those who completed the 24 week study (10/21, 48%), there was an improvement in their WHO functional class and a marked improvement in their health related quality of life as measured by the St. George Respiratory questionnaire (-15.3 +/- 25.0). However both these improvments did not reach statistical significance possibly because of the small sample size. CONCLUSION Although ambrisentan was not well tolerated by many of these subjects with SAPH, in those who remained in this 24-week trial, improvements in WHO functional class and in health related quality of life suggested a possible benefit of this drug in selected patients.
Collapse
|
5
|
Therapeutic failure in American cutaneous leishmaniasis is associated with gelatinase activity and cytokine expression. Clin Exp Immunol 2010; 163:207-14. [PMID: 21091666 DOI: 10.1111/j.1365-2249.2010.04285.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cutaneous lesions caused by Leishmania braziliensis infection occasionally heal spontaneously, but with antimonials therapy heal rapidly in approximately 3 weeks. However, about 15% of the cases require several courses of therapy. Matrix metalloproteinase-2 (MMP-2) and MMP-9 are gelatinases that have been implicated in other chronic cutaneous diseases and skin re-epithelialization. These enzymes are controlled by their natural inhibitors [tissue inhibitors of metalloproteinase (TIMPs)] and by some cytokines. Uncontrolled gelatinase activity may result in intense tissue degradation and, consequently, poorly healing wounds. The present study correlates gelatinase activity to therapeutic failure of cutaneous leishmaniasis (CL) lesions. Our results demonstrate an association between gelatinase activity and increased numbers of cells making interferon (IFN)-γ, interleukin (IL)-10 and transforming growth factor (TGF)-β in lesions from poor responders. Conversely, high levels of MMP-2 mRNA and enhanced MMP-2 : TIMP-2 ratios were associated with a satisfactory response to antimonials treatment. Additionally, high gelatinolytic activity was found in the wound beds, necrotic areas in the dermis and within some granulomatous infiltrates. These results indicate the importance of gelatinase activity in the skin lesions caused by CL. Thus, we hypothesize that the immune response profile may be responsible for the gelatinase activity pattern and may ultimately influence the persistence or cure of CL lesions.
Collapse
|
6
|
Direct red: a surgeon's story. MEDICAL HUMANITIES 2009; 35:123. [PMID: 23674713 DOI: 10.1136/jmh.2009.002063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
|
7
|
Inhaled iloprost for sarcoidosis associated pulmonary hypertension. SARCOIDOSIS, VASCULITIS, AND DIFFUSE LUNG DISEASES : OFFICIAL JOURNAL OF WASOG 2009; 26:110-120. [PMID: 20560291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
RATIONALE Patients with sarcoidosis associated pulmonary hypertension (SAPH) have responded to systemic prostacyclin therapy. OBJECTIVES To determine the rate of response to inhaled prostacyclin, iloprost, in SAPH. METHODS Sarcoidosis patients with pulmonary hypertension and no evidence for left ventricular dysfunction were enrolled in an open label, prospective study. Patients underwent right heart catheterization and six minute walk (6MW) test. Quality of life was evaluated using several instruments, including the Saint George Respiratory Questionnaire (SGRQ). Patients received 5 mcg of inhaled iloprost every 2-3 hours while awake. After four months of therapy, patients underwent repeat cardiac catheterization, 6 MW test, and completed quality of life questionnaires. MEASUREMENTS AND MAIN RESULTS Of the 22 patients enrolled, 15 completed all 16 weeks of therapy. The most common reasons for study discontinuation included drug associated cough (3 patients) and compliance with the prescribed number of treatments per day (2 patients). Six patients experienced a 20% or greater decrease in pulmonary vascular resistance (PVR) from baseline with five of these six patients also showing > or = 5 mm Hg reduction in PA mean. Although three patients improved the 6MW distance by at least 30 meters, only one had a decrease in PVR. At 16 weeks a significant decrease was reported in the SGRQ activity score (p = 0.0273), with seven patients having a 4 point or greater decrease. CONCLUSION Inhaled iloprost as monotherapy was associated with an improvement in pulmonary hemodynamics and quality of life as assessed by the SGRQ activity score in some sarcoidosis patients with SAPH.
Collapse
|
8
|
Navy Asbestos Medical Surveillance Program, 1995-1999: demographic characteristics and smoking status. Mil Med 2001; 166:966-71. [PMID: 11725325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
A descriptive study of the Navy Asbestos Medical Surveillance Program is presented from data provided by the Navy Environmental Health Center in Norfolk, Virginia, with an emphasis on demographic characteristics and smoking. Analysis of 79,598 physical examinations for the period 1995 to 1999 revealed that Navy and Marine Corps civil service employees constituted 90% and Navy active duty personnel constituted 9%. Most personnel reported "no current exposure, have prior exposure" to asbestos (Navy active duty, 77%; civil service employees, 61%). Current smoking rates per year decreased for Navy active duty (from 34.6% to 28.7%) and civil service workers (from 26.0% to 21.6%), both reductions being significant for trend. Logistic regression for current smoking showed higher rates for Navy active duty and those with "direct" asbestos exposure, whereas those 50 years or older and of Asian ethnicity had lower smoking rates. These findings provide programmatic insights for the Asbestos Medical Surveillance Program and suggest areas for further study.
Collapse
|
9
|
Serum carotenoids and radiographic knee osteoarthritis: the Johnston County Osteoarthritis Project. Public Health Nutr 2001; 4:935-42. [PMID: 11784406 DOI: 10.1079/phn2001132] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Antioxidant intake has been associated with less progression of radiographic knee osteoarthritis (OA), but studies of carotenoid biomarkers and OA have not been done. We examined associations between serum concentrations of nine naturally occurring carotenoids and radiographic knee OA. DESIGN The study design was matched case-control. Sera were analysed by high-performance liquid chromatography for nine carotenoids: lutein, zeaxanthin, alpha- and beta-cryptoxanthin, trans- and cis-lycopene, alpha-carotene, and trans- and cis-beta-carotene. Conditional logistic regression was used to estimate the association between tertiles of each carotenoid and radiographic knee OA, independent of body mass index, education, serum cholesterol, and the other carotenoids. SETTING Johnston County, North Carolina, United States of America. SUBJECTS Two-hundred cases with radiographic knee OA (Kellgren-Lawrence grades > or = 2) and 200 controls (Kellgren-Lawrence grade = 0) were randomly selected from the Johnston County Osteoarthritis Project, and were matched on age, gender and race. RESULTS Participants with serum levels of lutein or beta-cryptoxanthin in the highest tertile were approximately 70% less likely to have knee OA than controls (odds ratio (OR) [95% confidence interval (CI)] = 0.28 [0.11, 0.73] and 0.36 [0.14, 0.95], respectively). Those in the highest tertile of trans-beta-carotene (OR = 6.40 [1.86, 22.1]) and zeaxanthin (OR = 3.06 [1.19, 7.85]) were more likely to have knee OA. CONCLUSIONS While certain carotenoids may protect against knee OA, others may increase the odds of knee OA. Further study of carotenoids and knee OA are warranted before clinical recommendations about these substances and knee OA can be made.
Collapse
|
10
|
Evidence for clonal outgrowth of androgen-independent prostate cancer cells from androgen-dependent tumors through a two-step process. Cancer Res 1999; 59:5030-6. [PMID: 10519419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Prostate cancers require androgen for growth but progress to an androgen-independent stage under the selective pressure of androgen ablation therapy. Here we describe a novel human prostate cancer xenograft (LAPC-9) propagated by serial passage in male severe combined immunodeficient mice that expresses prostate-specific antigen and wild-type androgen receptor. In response to castration, LAPC-9 cells undergo growth arrest and persist in a dormant, androgen-responsive state for at least 6 months. After prolonged periods of androgen deprivation, spontaneous androgen-independent outgrowths develop. Thus, prostate cancers progress to androgen independence through two distinct stages, initially escaping dependence on androgen for survival and, subsequently, for growth. Through the use of serial dilution and fluctuation analysis, we provide evidence that the latter stage of androgen independence results from clonal expansion of androgen-independent cells that are present at a frequency of about 1 per 10(5)-10(6) androgen-dependent cells. We conclude that prostate cancers contain heterogeneous mixtures of cells that vary in their dependence on androgen for growth and survival and that treatment with antiandrogen therapy provides selective pressure and alters the relative frequency of these cells, thereby leading to outgrowths of androgen-independent cancers.
Collapse
|
11
|
Accumulation and retention of micellar β-carotene and lutein by Caco-2 human intestinal cells. J Nutr Biochem 1999; 10:573-81. [PMID: 15539253 DOI: 10.1016/s0955-2863(99)00044-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/1999] [Accepted: 06/28/1999] [Indexed: 10/16/2022]
Abstract
Despite the interest in the diverse roles of dietary carotenoids in human health, little is known about the transfer of these plant pigments from foods to micelles during digestion and their subsequent transfer across the intestinal epithelium. We conducted this study to characterize the intestinal uptake of micellarized carotenoids using monolayers of differentiated Caco-2 human intestinal cells. Crystalline beta-carotene (BC) and lutein (LUT), solubilized in mixed micelles for delivery to cells, were stable in a tissue culture environment for 20 hours. Cellular accumulation of micellar BC and LUT was proportional to the media content of carotenoids at </=2 micromol/L and the length of exposure. Cellular accumulation of BC routinely exceeded LUT and was due in part to the enhanced efflux or possible metabolism of LUT. Cellular BC content increased in a curvilinear manner when cultures were incubated in micellar medium containing 2 to 27 micromol/L BC prepared from water miscible beadlets; cellular BC content was maximum when medium BC was >/=18 micromol/L. There was no indication that high levels of BC in medium or within cells adversely affected micellar LUT accumulation. These data support the use of the Caco-2 human cell line as a model for studying the intestinal uptake, absorption, and possible interactions of dietary carotenoids.
Collapse
|
12
|
Abstract
Androgen blockade is the mainstay of therapy in the clinical management of advanced prostate cancer. Recent progress on two fronts--the development of newer xenograft and transgenic models and a greater understanding of nuclear receptor signaling--has provided new insight into mechanisms of androgen-dependence in prostate cancer. This review centers on the concept that perturbations in androgen receptor signaling are likely to occur early in prostate cancer and play a critical role in progression to end stage hormone-refractory disease.
Collapse
|
13
|
Medical Selection. West J Med 1999. [DOI: 10.1136/bmj.318.7199.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
14
|
A mechanism for hormone-independent prostate cancer through modulation of androgen receptor signaling by the HER-2/neu tyrosine kinase. Nat Med 1999; 5:280-5. [PMID: 10086382 DOI: 10.1038/6495] [Citation(s) in RCA: 738] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Prostate cancer progresses from a hormone-sensitive, androgen-dependent stage to a hormone-refractory, androgen-independent tumor. The androgen receptor pathway functions in these androgen-independent tumors despite anti-androgen therapy. In our LAPC-4 prostate cancer model, androgen-independent sublines expressed higher levels of the HER-2/neu receptor tyrosine kinase than their androgen-dependent counterparts. Forced overexpression of HER-2/neu in androgen-dependent prostate cancer cells allowed ligand-independent growth. HER-2/neu activated the androgen receptor pathway in the absence of ligand and synergized with low levels of androgen to 'superactivate' the pathway. By modulating the response to low doses of androgen, a tyrosine kinase receptor can restore androgen receptor function to prostate cancer cells, a finding directly related to the clinical progression of prostate cancer.
Collapse
|
15
|
Abstract
Health and development planners have tended to see women primarily in context of their reproductive role. As a result, solutions to women's health needs have been restricted to expanding and improving maternal and child health systems. There has recently been a major shift in direction, largely because of the influence of the world conference on population and development held in Cairo in 1994. Dr Guiseppe Benagiano, director of the special programme of research, development and research training in human reproduction based at the WHO, says, "We need to remind ourselves constantly that reproductive health is not simply a biomedical issue but one with serious implications for our general health and by extension, for all our efforts in human social and economic development." The 1993 world development report on health identified the lack of a clear strategy for engaging women in health care and suggested that child health services, prenatal care, treatment of sexually transmitted diseases, and family planning services should be provided jointly at convenient times. In an example of this, the Chilean Institute of Reproductive Medicine now offers integrated family planning services at the same time as child health services, and Thailand is experimenting with mobile health clinics to reach women in their homes. As the proportion of elderly women increases, old age is increasingly being seen as a female issue. With the impact of urbanisation and industrialisation, more of these women are living isolated lives, often suffering from chronic debilitating diseases. In his opening statement to the global commission on women's health in April 1995 which focused on health conditions of women in old age, Dr Hiroshi Nakajima, the WHO's director general, said: "Our goal should not be solely to extend lives in the physical sense, but to ensure that the added years are worth living."
Collapse
|
16
|
|
17
|
|
18
|
Age effects on interrelationships between lung volume and heart rate during standing. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:H2128-34. [PMID: 9374744 DOI: 10.1152/ajpheart.1997.273.5.h2128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To determine the effects of aging and posture on the relationship between respiration and heart rate (HR), we collected 5 min of lung volume and R-R interval data from 7 young (27 +/- 3 yr, mean +/- SD) and 10 old (69 +/- 6 yr) healthy humans during spontaneous breathing while they were supine (SU) and standing (ST). Lung volume and HR power spectra and transfer functions between lung volume and HR were estimated. Age and position effects and age-position interactions were determined by analysis of variance for repeated measures. Older subjects had a lower and more variable respiration rate (P < 0.03, P < 0.04), but both age groups exhibited decreased rate of respiration and increased tidal volume with ST (P < 0.05, P < 0.005). ST decreased lung volume-to-HR transfer function magnitude in both groups (P < 0.07). The more marked age-related differences were in phase angle. Both SU and ST phase angles were greater in older subjects (P < 0.003). ST decreased phase angle in young but increased phase angle in older subjects (P < 0.001). In conclusion, respiration, and respiration-HR interrelationships are altered by aging, with increased time delays between lung volume and HR and altered relationships with ST.
Collapse
|
19
|
|
20
|
|
21
|
A very public death. BMJ (CLINICAL RESEARCH ED.) 1997; 314:383-4. [PMID: 9040366 PMCID: PMC2125842 DOI: 10.1136/bmj.314.7077.383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
22
|
|
23
|
Looking living death in the face. West J Med 1996. [DOI: 10.1136/bmj.313.7069.1408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
24
|
Making the shortlist. West J Med 1996. [DOI: 10.1136/bmj.313.7066.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
25
|
Age and autonomic effects on interrelationships between lung volume and heart rate. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:H1833-40. [PMID: 8928893 DOI: 10.1152/ajpheart.1996.270.5.h1833] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To determine effects of aging and autonomic input on interrelationships between respiratory and heart rate variability, we collected 5 min of lung volume of R-R interval data from 7 young [27 +/- 3(SD) yr] and 10 older (69 +/- 6 yr) healthy supine humans before and after double pharmacological autonomic blockade with propranolol (0.2 mg/kg iv) and atropine (0.04 mg/kg iv). Estimates of respiratory and heart rate power spectra and linear transfer functions between the two groups were generated by Fourier analysis. Age, double blockade effects, the age-drug interactions were determined by analysis of variance for repeated measures. Basal R-R intervals were unaffected by age. Double blockade decreased R-R intervals and variability in both age groups (P < 0.0001), but R-R intervals decreased less in older than in young subjects (P < 0.0001). In contrast, basal respiratory intervals and standard deviation were greater in older subjects (P = 0.05) and were unaffected by double blockade in young and older subjects. Lung volume-to-heart rate spectral coherence was highest at frequencies associated with respiration and greater in young than in older subjects (P < 0.07). Double blockade decreased lung volume-to-heart rate variability transfer function magnitude (P < 0.007) and increased phase angle (P < 0.02) without age effects or age-drug interactions. In conclusion, heart rate, respiration, and respiration-heart rate interrelations are altered by aging, and double autonomic pharmacological blockade does not eliminate all age-related differences.
Collapse
|
26
|
|
27
|
Heart disease prevention needs attention. BMJ (CLINICAL RESEARCH ED.) 1995; 311:1525. [PMID: 8520390 DOI: 10.1136/bmj.311.7019.1525a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|
28
|
Whistleblowing in the Health Service: Accountability, Law and Professional Practice; Whistleblowing: Subversion or Corporate Citizenship? BRITISH MEDICAL JOURNAL 1995. [DOI: 10.1136/bmj.311.7017.1444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
29
|
|
30
|
|
31
|
|
32
|
Beijing conference struggles over women's health. West J Med 1995. [DOI: 10.1136/bmj.311.7007.708a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
33
|
|
34
|
|
35
|
Aid agencies' warning systems work. West J Med 1995. [DOI: 10.1136/bmj.310.6990.1283a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
36
|
Effects of age on intrinsic heart rate, heart rate variability, and AV conduction in healthy humans. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:H1441-52. [PMID: 7733345 DOI: 10.1152/ajpheart.1995.268.4.h1441] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Heart rate, heart rate variability, and atrioventricular (AV) conduction were studied in 20 young (30 +/- 5 yr) and 19 older (69 +/- 7 yr) healthy men and women before and after single and double autonomic blockade (randomized order: atropine, 0.04 mg/kg i.v.; propranolol, 0.2 mg/kg i.v.). Basal R-R intervals did not differ, but older age increased P-R intervals (177 +/- 24 vs. 149 +/- 17 ms, P < 0.001) and decreased SD of R-R (43 +/- 17 vs. 70 +/- 18 ms, P = 0.001) and heart rate spectral content (area under the power vs. frequency curve from 0.04 to 0.32 Hz: 3.01 +/- 2.1 vs. 7.82 +/- 4.8 beats/min2, P < 0.009), as well as postural responses (R-R decreases of 107 +/- 80 vs. 250 +/- 72 ms, P < 0.002). Atropine decreased R-R intervals, SD of R-R, and high-frequency (0.24-0.32 Hz) spectral content less in elderly subjects compared with younger subjects. Propranolol increased R-R and P-R intervals equally in old and young and abolished low-frequency (0.04-0.12 Hz) increases with standing (P < 0.0008). After double blockade, R-R, P-R, and paced AV intervals were longer in old subjects. Mean values were as follows: R-R intervals, 859 +/- 176 vs. 677 +/- 106 ms, P < 0.001; P-R intervals, 179 +/- 23 vs. 149 +/- 17 ms, P = 0.0002; paced P-R intervals (500 ms), 251 +/- 39 vs. 215 +/- 47 ms; and AV block cycle length, 413 +/- 51 vs. 385 +/- 69 ms (multivariate analysis of variance, P < 0.03). After double autonomic blockade, heart rate variability was nearly eliminated in young and old (reduced > 98%, P < 0.0001). We conclude that age differences in heart rate variability can be explained by autonomic influences, but heart rate and AV conduction differences exist independently of beta-adrenergic and/or parasympathetic influences.
Collapse
|
37
|
|
38
|
|
39
|
WHO denounces health benefits of alcohol. BMJ (CLINICAL RESEARCH ED.) 1994; 309:1249. [PMID: 7888835 PMCID: PMC2541783 DOI: 10.1136/bmj.309.6964.1249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
40
|
|
41
|
Petrol pollution worries royal commission. BMJ (CLINICAL RESEARCH ED.) 1994; 309:1183. [PMID: 7987143 DOI: 10.1136/bmj.309.6963.1183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
42
|
Food irradiation is safe, says WHO. West J Med 1994. [DOI: 10.1136/bmj.309.6962.1110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
43
|
New test for invalidity is accused of unfairness. West J Med 1994. [DOI: 10.1136/bmj.309.6960.978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
44
|
Assessment of homology with the helical mimicry algorithm. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1204:181-8. [PMID: 8142458 DOI: 10.1016/0167-4838(94)90007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Homologies based on structural motifs characterize conserved structures and mechanisms of maintaining function. An algorithm was developed to quantitate homology among segments of two proteins based upon structural characteristics of an amphipathic alpha-helix. This helical mimicry algorithm scored homology among sequences of two proteins in terms of: (i) presence of Leu, Ile, Val, Phe, or Met in a longitudinal, hydrophobic strip-of-helix at positions n, n + 4, n + 7, n + 11, etc. in the primary sequence, (ii) identity or chemical similarity of amino acids at intervening positions and (iii) exchanges of amino acids from positions n to n - 1, n + 3, n + 4, n + 1, n - 3, n - 4 around n (on the surface of a putative helix). While such exchanges of amino acids on the surfaces of homologous helices may conserve function, they did not maintain specific interactions of those residues with apposing groups.
Collapse
|
45
|
Calcium antagonists block angiotensin II-mediated vasoconstriction in humans: comparison with their effect on phenylephrine-induced vasoconstriction. J Pharmacol Exp Ther 1992; 261:879-84. [PMID: 1602392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Calcium antagonists are known to decrease peripheral vascular resistance in vivo in humans. The mechanism of this vascular relaxation has not been clearly elucidated. Vascular tone is maintained by several endogenous neurohumoral systems including sympathetic nervous system activity and angiotensin II. We compared and contrasted the capacity of calcium antagonist drugs to prevent angiotensin II and phenylephrine-induced alpha-1 adrenergic vasoconstriction using brachial artery infusion and measurement of forearm blood flow by strain gauge plethysmography. In a dose-dependent manner, calcium antagonists blocked angiotensin II-induced vasoconstriction. The rank order of this blockade was nifedipine greater than verapamil greater than diltiazem. Nifedipine and verapamil, but not diltiazem blocked alpha-1 adrenergic (phenylephrine-induced) vasoconstriction. At 7.64 and 19.1 micrograms/min infusion rates for nifedipine and verapamil, respectively, they abolished the angiotensin II effect; however, the phenylephrine effect was incompletely blocked. Calcium antagonist-induced vascular relaxation in vivo in humans is in part explained by their capacity to block angiotensin II-mediated vasoconstriction. In addition, two calcium antagonists (nifedipine and verapamil) may inhibit alpha-1 adrenergic vasoconstriction.
Collapse
|
46
|
Abstract
The specific cause of short stature in juvenile rheumatoid arthritis (JRA) is unknown. One hypothesis links altered growth to inadequate dietary intake. In this study, nutritional status was assessed in 34 children with JRA (8 with systemic JRA, 14 with polyarticular JRA, and 12 with pauciarticular JRA) and 9 healthy controls using 3-day diet records, anthropometrics, and biochemical analyses. Differences in growth were found among the three types of JRA. One third of all subjects were at or below the 10th percentile in height for age (these being predominantly among the systemic and polyarticular groups). With few exceptions, the mean dietary intake for calories and essential nutrients was found to be adequate for each of the three groups. However, more than half of those with systemic JRA reportedly consumed less than the recommended caloric intake for their age and weight. No significant correlations were found linking dietary intake to growth percentiles in any of the groups studied. Biochemical abnormalities were found among the systemic and polyarticular groups. These abnormalities included low plasma levels of vitamins A and C, proteins (albumin, prealbumin, and retinol binding protein) and zinc; and increased levels of copper and glutathione peroxidase activity. Plasma selenium and vitamin E levels were unchanged. The discrepancy between intake and certain circulating nutrient levels may reflect alterations in the requirements, absorption, or use of these nutrients in the presence of chronic inflammation.
Collapse
|
47
|
Concentrations of carotenoids, retinol, and tocopherol in plasma, in response to ingestion of a meal. Clin Chem 1989; 35:310-2. [PMID: 2914382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Field studies and epidemiological surveys may necessitate obtaining a blood sample from a nonfasted subject for nutritional assessments. We measured the effect of a standardized test meal, eaten after an overnight fast, on the concentrations of seven carotenoid fractions, retinol, and tocopherol in plasma of eight healthy adults. The 790-calorie test meal did not alter the measured concentrations. We conclude that blood sampled up to 4 h after breakfast can be validly used for these measurements.
Collapse
|
48
|
Concentrations of carotenoids, retinol, and tocopherol in plasma, in response to ingestion of a meal. Clin Chem 1989. [DOI: 10.1093/clinchem/35.2.310] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Field studies and epidemiological surveys may necessitate obtaining a blood sample from a nonfasted subject for nutritional assessments. We measured the effect of a standardized test meal, eaten after an overnight fast, on the concentrations of seven carotenoid fractions, retinol, and tocopherol in plasma of eight healthy adults. The 790-calorie test meal did not alter the measured concentrations. We conclude that blood sampled up to 4 h after breakfast can be validly used for these measurements.
Collapse
|
49
|
Abstract
This study describes the progressive changes in exocrine pancreatic enzyme specific activities from rats provided with a diet containing either 62% starch (S) or fructose (F) with 6.0 ppm copper (+Cu) or 0.6 ppm (-Cu) from 21 to 61 days of age. Copper-deficient rats had significantly reduced pancreatic weight and DNA, RNA, protein and copper content and superoxide dismutase (SOD) activity after consuming diet for 39 days. These reductions were far more severe in F-Cu than in S-Cu rats. Copper deficiency significantly reduced pancreatic amylase and lipase specific activities, but the effect was more severe in the F-Cu dietary group. Chymotrypsinogen and trypsinogen specific activities were reduced only in the F-Cu dietary group and the CHO x Cu interaction was significant. High dietary fructose and low dietary copper in combination interact to produce severe reductions in pancreatic amylase, lipase, chymotrypsinogen, and trypsinogen specific activities which could not be explained by either copper deficiency or by an increase in dietary fructose alone.
Collapse
|
50
|
Alteration of pancreatic enzyme activities in small intestine of rats fed a high fructose, low copper diet. J Nutr 1987; 117:1447-52. [PMID: 2442328 DOI: 10.1093/jn/117.8.1447] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
This study describes the progressive effects on pancreatic enzyme activities from washings of the small intestine of rats fed diets containing either 62% starch (S) or fructose (F), with 0.6 mg copper/kg diet (-Cu) or 6.0 mg copper/kg diet (+Cu) from 21 to 61 d of age. Hepatic copper concentration of the copper-deficient groups was 50% of that of the copper-supplemented groups. Body and relative pancreatic weights were lower in the F-Cu dietary group than in any other group. Relative liver weight was significantly higher in the fructose dietary groups than in the starch dietary groups. There were significant carbohydrate (CHO) X week and Cu X week interactions for luminal amylase activities and the CHO X Cu X week interaction was significant for luminal lipase and trypsin activities. The lowest enzyme activities were observed in the F-Cu-fed rats. The CHO X week interaction was significant for chymotrypsin with the lowest enzyme activities in the fructose-fed rats. It appears that high dietary fructose and low dietary copper interact to produce greatly reduced pancreatic enzyme activities in small intestinal washings. We speculate that subsequent digestive and absorptive abnormalities during a period of rapid growth may account for the severe morbidity and mortality in copper-deficient, fructose-fed rats.
Collapse
|