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Daily patterns in parasite processes: diel variation in fish louse transcriptomes. Int J Parasitol 2022; 52:509-518. [PMID: 35533730 DOI: 10.1016/j.ijpara.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 11/05/2022]
Abstract
Parasites, similar to all other organisms, time themselves to environmental cues using a molecular clock to generate and maintain rhythms. Chronotherapeutic (timed treatment) techniques based on such rhythms offer great potential for improving control of chronic, problematic parasites. Fish lice are a key disease threat in aquaculture, with current control insufficient. Assessing the rhythmicity of fish lice transcriptomes offers not only insight into the viability of chronotherapy, but the opportunity to identify new drug targets. Here, for the first known time in any crustacean parasite, diel changes in gene transcription are examined, revealing that approximately half of the Argulus foliaceus annotated transcriptome displays significant daily rhythmicity. We identified rhythmically transcribed putative clock genes including core clock/cycle and period/timeless pairs, alongside rhythms in feeding-associated genes and processes involving immune response, as well as fish louse drug targets. A substantial number of gene pathways showed peak transcription in hours immediately preceding onset of light, potentially in anticipation of peak host anti-parasite responses or in preparation for increased feeding activity. Genes related to immune haemocyte activity and chitin development were more highly transcribed 4 h post light onset, although inflammatory gene transcription was highest during dark periods. Our study provides an important resource for application of chronotherapy in fish lice; timed application could increase efficacy and/or reduce dose requirement, improving the current landscape of drug resistance and fish health while reducing the economic cost of infection.
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Patient perspectives of the cumulative life course impairment of alopecia areata. Clin Exp Dermatol 2021; 46:935-936. [PMID: 33548059 DOI: 10.1111/ced.14597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/18/2021] [Accepted: 02/01/2021] [Indexed: 12/14/2022]
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Alopecia universalis: a patient's perspective of the cumulative life course impairment. Clin Exp Dermatol 2021; 46:1353-1354. [PMID: 33740296 DOI: 10.1111/ced.14596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 11/28/2022]
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A neglected fish stressor: mechanical disturbance during transportation impacts susceptibility to disease in a globally important ornamental fish. DISEASES OF AQUATIC ORGANISMS 2019; 134:25-32. [PMID: 32132270 DOI: 10.3354/dao03362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The transport of fish in aquaculture and the ornamental trade exposes fish to multiple stressors that can cause mass mortalities and economic loss. Previous research on fish transport has largely focussed on chemical stress related to deterioration in water quality. However, mechanical disturbance during routine fish transport is unpredictable and is a neglected potential stressor when studying fish welfare. Stress-induced immunosuppression caused by mechanical disturbance can increase the chances of contracting infections and can significantly increase infection burden. Here, using a model host-parasite system (guppy Poecilia reticulata and the monogenean ectoparasite Gyrodactylus turnbulli) and a new method of bagging fish (Breathing Bags™), which reduces mechanical disturbance during fish transport, we investigated how parasite infections contracted after simulated transport impact infection trajectories on a globally important ornamental freshwater species. Guppies exposed to mechanical transport disturbance suffered significantly higher parasite burden compared to fish that did not experience transport disturbance. Unfortunately, there was no significant reduction in parasite burden of fish transported in the Breathing Bags™ compared to standard polythene carrier bags. Thus, transport-induced mechanical disturbance, hitherto neglected as a stressor, can be detrimental to disease resistance and highlights the need for specific management procedures to reduce the impact of infectious diseases following routine fish transport.
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Balancing selection and the maintenance of MHC supertype variation in a selfing vertebrate. Proc Biol Sci 2013; 280:20122854. [DOI: 10.1098/rspb.2012.2854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Maintaining functional major histocompatibility complex diversity under inbreeding: the case of a selfing vertebrate. Proc Biol Sci 2012; 279:5004-13. [PMID: 23075838 PMCID: PMC3497237 DOI: 10.1098/rspb.2012.1929] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/24/2012] [Indexed: 01/17/2023] Open
Abstract
Major histocompatibility complex (MHC) genes encode proteins that present pathogen-derived antigens to T-cells, initiating the adaptive immune response in vertebrates. Although populations with low MHC diversity tend to be more susceptible to pathogens, some bottlenecked populations persist and even increase in numbers despite low MHC diversity. Thus, the relative importance of MHC diversity versus genome-wide variability for the long-term viability of populations after bottlenecks and/or under high inbreeding is controversial. We tested the hypothesis that genome-wide inbreeding (estimated using microsatellites) should be more critical than MHC diversity alone in determining pathogen resistance in the self-fertilizing fish Kryptolebias marmoratus by analysing MHC diversity and parasite loads in natural and laboratory populations with different degrees of inbreeding. Both MHC and neutral diversities were lost after several generations of selfing, but we also found evidence of parasite selection acting on MHC diversity and of non-random loss of alleles, suggesting a possible selective advantage of those individuals with functionally divergent MHC, in accordance with the hypothesis of divergent allele advantage. Moreover, we found that parasite loads were better explained by including MHC diversity in the model than by genome-wide (microsatellites) heterozygosity alone. Our results suggest that immune-related overdominance could be the key in maintaining variables rates of selfing and outcrossing in K. marmoratus and other mixed-mating species.
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Decoding emotional prosody: resolving differences in functional neuroanatomy from fMRI and lesion studies using TMS. Brain Stimul 2011; 5:347-353. [PMID: 21824835 DOI: 10.1016/j.brs.2011.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 06/15/2011] [Indexed: 10/17/2022] Open
Abstract
BACKGROUND Prosody conveys information about the emotional state and intention of others. Lesion studies have shown that damage to the right posterior temporal region is associated with prosody decoding deficits. Dissimilarly to findings from lesion studies, neuroimaging data show substantial bilateral peri-Sylvian activation. OBJECTIVE This study aimed to investigate the involvement of the left and right superior temporal gyrus (STG) in prosodic and semantic processing using transcranial magnetic stimulation (TMS). These two regions of interest were chosen for their correspondence to Wernicke's area in the left hemisphere and its analog in the right. METHODS Offline TMS with a stimulation frequency of 1 Hz and intensity of 60% of stimulator output (approximately 1.1 Tesla) with one pulse applied per second for 10 minutes (600 pulses) was performed. Directly after TMS on the right STG, the left STG or sham-stimulation, participants completed a prosody decoding or a semantic judgment task (whether the tone/meaning was happy or sad). RESULTS Reaction times (RT) for the prosodic task were significantly slower when TMS was applied in the right STG in comparison to left STG and sham conditions. TMS over both right and left STG delayed RT in the semantic task, significantly when the tone of voice was incongruent with the meaning. CONCLUSIONS Our data strongly suggests that left temporal regions are not crucial to the basic task of prosody decoding per se; however, the analogous region on the right is. Hence, involvement of the left STG in prosodic decoding revealed in previous imaging data is incidental.
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Is posterior parietal cortical involvement in visual search contingent upon frontal eye field activity? A dual site TMS study. Brain Stimul 2008. [DOI: 10.1016/j.brs.2008.06.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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The co-involvement of the ventral and dorsal visual streams in spatial tasks investigated with dual-site TMS. Brain Stimul 2008. [DOI: 10.1016/j.brs.2008.06.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Full recovery of electron damage in glass at ambient temperatures. PHYSICAL REVIEW LETTERS 2006; 96:205506. [PMID: 16803186 DOI: 10.1103/physrevlett.96.205506] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Indexed: 05/10/2023]
Abstract
An unusually complete recovery of extensive electron-beam-induced damage in a thin film of a CaO-Al2O3-SiO2 glass was discovered. Nanoscale measurements show that the Ca ions migrate about 10 nm away during irradiation and return during recovery. Oxygen atoms are trapped largely as molecular oxygen and do not migrate. Electron energy loss measurements demonstrate that the glass returns completely to the original compositional and structural state thus indicating that the glass is in a deep thermodynamic energy minimum.
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Abstract
It has been suggested that attentional resolution is greater in the lower than in the upper visual field. As there is no corresponding asymmetry between the areas in the primary visual cortex where the input from upper and lower visual fields is processed, an 'attentional filter' has been proposed to act in one or more higher visual cortical areas in order to constrict the availability of visual information to the level of awareness. To investigate this, a visual search array was presented to the entire visual field and reaction times from upper and lower visual fields compared. In a second experiment, subjects were trained in detecting targets in different visual fields. There was no significant difference between reaction times for targets presented in either upper or lower visual fields when the array was presented to the entire visual field. However, when the array was restricted to either the upper or lower visual fields, reaction times were significantly slower for detection in the upper visual field.
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Abstract
It is widely agreed that the right posterior parietal cortex has a preeminent role in visuospatial and orienting attention. A number of lines of evidence suggest that although orienting and the preparation of oculomotor responses are dissociable from each other, the two are intimately related. If this is true, then it should be possible to identify other attentional mechanisms tied to other response modalities. We used repetitive transcranial magnetic stimulation (rTMS) to demonstrate the existence of a distinct anterior parietal mechanism of motor attention. The critical area for motor attention is anterior to the one concerned with orienting, and it is lateralized to the left hemisphere in humans.
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The role of transcranial magnetic stimulation (TMS) in studies of vision, attention and cognition. Acta Psychol (Amst) 2001; 107:275-91. [PMID: 11388139 DOI: 10.1016/s0001-6918(01)00035-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can be conceptualized as a virtual lesion technique, capable of disrupting organized cortical activity, transiently and reversibly. The technique combines good spatial and temporal resolution and, moreover, because it represents an interference technique, can be said to have excellent functional resolution. The following is a review and discussion of the contribution which TMS has made to the study of vision, attention, development and plasticity and speech and language.
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Abstract
BACKGROUND Few studies have been done of bone densities in humans receiving retinoids, despite a substantial amount of literature concerning retinoid-induced osteoporosis in animals. We prospectively measured bone density and calcium metabolism in young men (aged 17-25 years) receiving oral isotretinoin for cystic acne and in a group of healthy volunteers (aged 19-26 years). OBSERVATIONS Compared with that in healthy control subjects, mean bone density was lower at all sites (spine, femoral neck, and Ward triangle) and was considerably more variable at the spine in young men with cystic acne even before treatment. Bone density at the Ward triangle decreased a mean of 4.4% (P = .03) after 6 months of isotretinoin use (1 mg/kg of body weight). Four patients showed decreased density of more than 9% at the Ward triangle. The difference between the mean change in bone density in the patient group and in the control group was significant at the Ward triangle (P = .04) but not at the other sites. Measurements of calcium metabolism did not change over time in either group. CONCLUSIONS A loss of bone density occurring in the absence of measurable alterations of calcium metabolism is likely to be a direct effect of retinoids on bone. Further study of retinoid-induced osteoporosis in humans and of bone density in patients with cystic acne is needed.
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The role of the parietal cortex in visual attention--hemispheric asymmetries and the effects of learning: a magnetic stimulation study. Neuropsychologia 1999; 37:245-51. [PMID: 10080382 DOI: 10.1016/s0028-3932(98)00099-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Our previous studies of the role of the parietal cortex in visual learning and attention showed that the right parietal cortex is required for normal performance on conjunction visual search tasks but that its role depends on whether subjects are naive or trained on the task. Here we extend these findings in two Experiments. Experiment 1 shows that magnetic stimulation of the left parietal cortex also impairs performance (measured as reaction time) on conjunction visual search tasks, but only when the target is present in the right (contralateral) visual field. Stimulation of the same region on a feature detection task speeds up performance significantly when the target is in the left (ipsilateral) visual field. Experiment 2 explores further the role of the right parietal cortex in learning conjunction search tasks. Stimulation of the right parietal cortex in subjects who had already trained on some visual search tasks did not impair performance on a novel motion/form conjunction task even though the search was clearly serial. Stimulation of area V5, however, severely disrupted performance on the same task. These data indicate that the role of the parietal cortex may change much earlier in the course of training than initially thought.
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Seed dispersal characteristics of Brassavola nodosa (Orchidaceae). AMERICAN JOURNAL OF BOTANY 1998. [PMID: 21684949 DOI: 10.2307/2446537] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We used mathematical models for wind-dispersed seeds and wind-tunnel experiments to predict modal seed dispersal distance of the Neotropical orchid Brassavola nodosa under conditions approximating those found in its natural habitat: mangrove islands in Belize, Central America. Key variables in a simple ballistic model for predicting modal dispersal distance (xm) of an individual seed include: height of release (h); free-stream velocity (Uc); and terminal velocity of the seed (Ut): xm = h Uc/Ut. Modal dispersal distance of dust-like orchid seeds were predicted adequately by this ballistic model at low wind velocities and low release heights, but it underestimated the increasing importance of turbulence at higher wind velocities and greater release heights. We estimated the magnitude and relative importance of one measure of turbulence, vertical mixing velocity (W*), on xm in wind tunnel experiments. Our estimates of W* were within the same order of magnitude as those found for other small dust-like seeds and pollen. In high turbulence conditions, incorporation of vertical mixing velocity effects into the ballistic model of seed dispersal overestimated modal seed dispersal distances.
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Task-specific impairments and enhancements induced by magnetic stimulation of human visual area V5. Proc Biol Sci 1998; 265:537-43. [PMID: 9569672 PMCID: PMC1688918 DOI: 10.1098/rspb.1998.0328] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Transcranial magnetic stimulation (TMS) can be used to simulate the effects of highly circumscribed brain damage permanently present in some neuropsychological patients, by reversibly disrupting the normal functioning of the cortical area to which it is applied. By using TMS we attempted to recreate deficits similar to those reported in a motion-blind patient and to assess the specificity of deficits when TMS is applied over human area V5. We used six visual search tasks and showed that subjects were impaired in a motion but not a form 'pop-out' task when TMS was applied over V5. When motion was present, but irrelevant, or when attention to colour and form were required, TMS applied to V5 enhanced performance. When attention to motion was required in a motion-form conjunction search task, irrespective of whether the target was moving or stationary, TMS disrupted performance. These data suggest that attention to different visual attributes involves mutual inhibition between different extrastriate visual areas.
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Abstract
To test a recent suggestion that perceptual learning in visual search is non-specific, two groups of subjects were trained on visual search tasks and tested for transfer of learning to new tasks. One group was trained on parallel ("pop-out") tasks and transferred to serial, conjunction tasks and the other group trained on conjunction and transferred to pop-out. Some (not all) tasks which are initially serial, rapidly became parallel. Some transfer occurred between the different types of tasks. Under some conditions transfer was either absent or even negative. The specificities observed may reflect the roles of the brain regions involved in learning.
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Abstract
OBJECTIVE AND DESIGN Cystic fibrosis (CF) sputum contains large numbers of neutrophils whose most abundant granule proteins are defensins. Within phagolysosomes, defensins kill microbes; however, extracellular defensins can be toxic to human cells. To begin to explore the possibility that defensins damage CF airways, this study examines the concentration and properties of defensins in CF sputum. MATERIALS As a source of biological material in which to assay levels of defensins, purulent sputum was collected from persons with CF hospitalized with exacerbations of bronchitis. Purulent CF sputum was also a source of material for purification of defensins. METHODS Defensin concentration in the cell-free component of CF sputum was measured by immunoassay. Defensins acid-extracted from sputum were purified by Sephacryl S-200 gel filtration chromatography and reverse phase-high pressure liquid chromatography (HPLC). Toxicity of CF defensins was tested by incubating the purified defensins with a line of CF tracheal cells cultured in serum five medium. RESULTS In 5 patients with CF, sputum defensin levels ranged from 300 to > 1600 micrograms/ml, higher than levels previously reported in any human secretion or fluid and greatly exceeding concentrations toxic to mammalian cells in vitro. HPCL-purified CF sputum defensins were pure as judged by acid urea-PAGE and N-terminal sequencing, which revealed a mixture of defensins-1, -2 and -3 at ratios of approximately 4:2:1. At > 10 micrograms/ml the purified mixture was toxic for a line of CF tracheal cells cultured in serum-free medium, as judged by reductions in cell numbers and increased permeability to trypan blue. CONCLUSIONS This study suggests that defensins in CF sputum are intact and sufficiently abundant that they may damage airway epithelium.
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Circulating levels of interleukin-6 and tumor necrosis factor-alpha are elevated in primary hyperparathyroidism and correlate with markers of bone resorption--a clinical research center study. J Clin Endocrinol Metab 1996; 81:3450-4. [PMID: 8855783 DOI: 10.1210/jcem.81.10.8855783] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The pathogenesis of PTH-induced bone loss is uncertain. Experimental evidence suggests that PTH induces the production by osteoblasts of the bone-resorbing cytokine, interleukin-6. We measured the circulating levels of interleukin-6, tumor necrosis factor-alpha, and interleukin-1 beta and examined their relationship to biochemical markers of bone turnover in 38 patients with primary hyperparathyroidism (7 of whom also were studied after successful parathyroid adenomectomy), 6 patients with hypoparathyroidism, and 12 subjects with normal parathyroid function. The patients with untreated primary hyperparathyroidism had mean serum levels of interleukin-6 that were 16-fold higher than control values (mean +/- SEM; primary hyperparathyroidism 18.6 +/- 2.1 pg/mL, controls 1.1 +/- 0.1; P < 0.001). Circulating levels of interleukin-6 soluble receptor (primary hyperparathyroidism 41.7 +/- 1.2 ng/ mL, controls 25.1 +/- 1.0; P < 0.001), and tumor necrosis factor-alpha (primary hyperparathyroidism 11.6 +/- 0.8 pg/mL, controls 2.5 +/- 0.2; P < 0.001) were also elevated. After successful parathyroid adenomectomy, levels of each of these cytokines fell into the normal range. The mean levels of interleukin-6, its soluble receptor, and tumor necrosis factor-alpha in the subjects with hypoparathyroidism were lower than control values (P < 0.001 for each variable). There was no difference between subjects with primary hyperparathyroidism and controls in the circulating level of interleukin-1 beta. In the subjects with untreated primary hyperparathyroidism, serum levels of interleukin-6 correlated strongly with those of intact PTH (r = 0.47, P = 0.003) and biochemical markers of bone resorption: serum deoxypyridinoline (r = 0.93, P < 0.001), serum type I collagen carboxyterminal telopeptide (r = 0.87, P < 0.001), urinary pyridinoline (r = 0.81, P < 0.001), and urinary deoxypyridinoline (r = 0.63, P = 0.005). Levels of tumor necrosis factor-alpha correlated less strongly with the same variables: PTH (r = 0.41, P = 0.01), serum deoxypyridinoline (r = 0.48, P = 0.002), serum type I collagen carboxyterminal telopeptide (r = 0.46, P = 0.004), urinary pyridinoline (r = 0.61, P = 0.008), and urinary deoxypyridinoline (r = 0.61, P = 0.007). Levels of interleukin-6 also correlated with those of tumor necrosis factor-alpha (r = 0.44, P = 0.005). Multiple regression analysis indicated that interleukin-6, but not tumor necrosis factor-alpha, was independently predictive of bone resorption. We conclude that serum levels of interleukin-6 and tumor necrosis factor-alpha are increased in patients with primary hyperparathyroidism and are normalized by successful surgical treatment. The finding that these cytokines correlate with biochemical markers of bone resorption suggests that they play a role in the pathogenesis of bone loss in primary hyperparathyroidism.
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24,25 Dihydroxyvitamin D supplementation corrects hyperparathyroidism and improves skeletal abnormalities in X-linked hypophosphatemic rickets--a clinical research center study. J Clin Endocrinol Metab 1996; 81:2381-8. [PMID: 8964881 DOI: 10.1210/jcem.81.6.8964881] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Therapy for X-linked hypophosphatemia (XLH) only partially corrects skeletal lesions and is often complicated by hyperparathyroidism. 24,25(OH)2 D3 improves skeletal lesions in a murine model of XLH and suppresses PTH secretion in animals. Therefore, we undertook a placebo-controlled trial of 24,25(OH)2 D3 supplementation to standard treatment in patients with XLH to improve bone disease and reduce hyperparathyroid complications. Fifteen subjects with XLH receiving standard treatment [1,25(OH)2 D3 or dihydrotachysterol plus phosphate] were evaluated, supplemented with placebo, and reevaluated one yr later. 24,25(OH)2 D3 supplementation was then begun and studies repeated after another year. Each patient underwent a detailed evaluation of calcium homeostasis over a 24-h period. Rachitic abnormalities were assessed radiographically in children. Adults underwent bone biopsies. 24,25(OH)2 D3 normalized PTH values in nine subjects (peak PTH was 46.5 +/- 6.6 pmol/L at entry, 42.3 +/- 5.9 pmol/L after placebo, and 23.3 +/- 5.4 pmol/L after 24,25(OH)2 D3). Nephrogenous cAMP decreased at night, coincident with the decrease in PTH, and serum phosphorus was slightly greater with 24,25(OH)2 D3. Radiographic features of rickets improved during 24,25(OH)2 D3 supplementation in children, and osteoid surface decreased in adults. 24,25(OH)2 D3 is a useful adjunct to standard therapy in XLH by effecting correction of hyperparathyroidism and improvement of rickets and osteomalacia.
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Use of bioluminescence to model the thermal inactivation of Salmonella typhimurium in the presence of a competitive microflora. Appl Environ Microbiol 1995; 61:3463-5. [PMID: 7574653 PMCID: PMC167623 DOI: 10.1128/aem.61.9.3463-3465.1995] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The survival of Salmonella typhimurium was investigated by bioluminescence and standard plating techniques in pure cultures and in the presence of competitors after the cultures were heated to 55 degrees C for increasing lengths of time. Decimal reduction (D) values increased from 0.43 to 2.09 min in the presence of 10(8) CFU of competitors ml-1, indicating a significant protective effect.
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Abstract
Inactivation of micro-organisms by heat is a traditional food processing technique used to reduce or eliminate the microbial load in foods thus preventing bacterial associated disease and food spoilage. Models of thermal death kinetics are routinely used to predict the amount of heat required but such models are limited by the acquisition of accurate thermal death data for bacteria in situ and in complex microflora. In vivo bioluminescence from lux recombinant bacteria is an important alternative to traditional plate counts for examining bacterial injury and stress but the thermal instability of luciferase has appeared to preclude its application in heating studies. We have developed a procedure which overcomes the thermal instability of luciferase and demonstrate that computer generated models of the thermal injury of Salmonella typhimurium show equivalence between bioluminescence and viable count data.
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Abstract
The relative importance of dietary factors in causing hypercalciuria was assessed in 282 unselected patients with calcium oxalate kidney stones. The 124 patients found to be hypercalciuric on either their customary free diet or on a 25-mmol (1000-mg) calcium defined diet (or both), were classified according to their pattern of calcium excretion on the two diets. Unexpectedly, about half of the patients who were hypercalciuric on their free diet exhibited a calcium excretion that fell markedly or normalized on the high-calcium defined diet. These patients were defined as having dietary hypercalciuria. For all 282 patients, multiple-regression analysis suggested that dietary sodium was at least as important as was dietary calcium, and more important than dietary protein, carbohydrate, phosphorus, purine, or oxalate, in contributing to calcium excretion on the free diet. Among the 124 hypercalciuric patients, urinary calcium excretion increased by 0.0193 mmol (0.77 mg) per mmol sodium excretion. Dietary habits, particularly a high sodium intake, may commonly contribute to hypercalciuria in patients with calcium oxalate stones.
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Abstract
Parathyroid function is described as normal in patients with phosphopenic rickets before initiation of therapy with phosphate salts; however, hyperparathyroidism is an occasional complication of treatment. We observed a higher than expected frequency of hyperparathyroidism in patients with phosphate-wasting rickets, present before treatment in some patients and, more frequently, after the onset of treatment. To better define parathyroid status in hypophosphatemic rickets, we sampled 12 affected children and 7 affected adults every 4 h for 1 day and measured PTH in assays detecting midmolecule fragments (cPTH) and intact hormone (iPTH). All children and 4 adults were receiving a vitamin D preparation and phosphate salts; 3 adults were untreated. Mean cPTH, iPTH, and nephrogenous cAMP excretions in each group of patients were greater than in controls. Exaggerated nocturnal rises in both cPTH and iPTH characterized the profile in patients. Seventeen patients demonstrated frankly elevated cPTH at night, with peak values at midnight, whereas no control individual did. Although mean iPTH values in patients increased at night, they did not exceed the upper limit of normal. Hyperparathyroidism in hypophosphatemic rickets occurs in both children and adults, may be present in untreated patients, is predominantly nocturnal, and is characterized by exaggerated secretion of midmolecule fragments. This manifestation of hypophosphatemic rickets is more widespread than currently recognized; we speculate that it may contribute to the pathogenesis of nephrocalcinosis and precede the development of tertiary hyperparathyroidism.
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Resistance of rat embryonic heart cells to the cytotoxic effects of cyclophosphamide does not involve aldehyde dehydrogenase-mediated metabolism. TERATOLOGY 1991; 43:307-18. [PMID: 2048039 DOI: 10.1002/tera.1420430405] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
Bioluminescence provides a novel tool with which to probe in real time the recovery of microorganisms such as Salmonella typhimurium from sub-lethal injury, a condition of immense importance in the enumeration of microorganisms in food and environmental samples such as from estuarine waters. We describe the application of in vivo bioluminescence to monitor the recovery of S. typhimurium from freeze injury and, in addition, we explore the effect of multiple stress conditions on microbial recovery where we compare bioluminescence with viable count measurement.
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In vivo bioluminescence: a cellular reporter for research and industry. JOURNAL OF BIOLUMINESCENCE AND CHEMILUMINESCENCE 1990; 5:115-22. [PMID: 2159685 DOI: 10.1002/bio.1170050207] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The detection of specific bacterial pathogens, indicator microorganisms and antimicrobial substances, and the recovery of microorganisms from sub-lethal injury, are all aspects of importance to industry which are currently being targeted using in vivo bioluminescence. In all instances, a key requirement for the application of bioluminescence is the establishment of a strict correlation between in vivo bioluminescence and cell viability, as determined by colony counting on agar plates. Comparative studies for biocides (phenol, chlorhexidine diacetate, phenol thioether), for a virucide (hypochlorite) and for cellular recovery of S. typhimurium from sub-lethal injury, all indicate that such a correlation is valid. Furthermore, real-time measurements of in vivo bioluminescence reveal a major population of bacterial cells that retain functional intracellular biochemistry, but are defective in their ability to replicate post of freeze injury.
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Role of aldehyde dehydrogenase (ALDH) in the detoxication of cyclophosphamide (CP) in rat embryos. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 284:85-95. [PMID: 2053494 DOI: 10.1007/978-1-4684-5901-2_11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
Fifty organisms of Pseudomonas aeruginosa were injected intralamellarly in both eyes of 60 albino rabbits. Twenty-four hours later, all eyes were graded and stratified into six groups of ten rabbits with equivalent infections. Treatment was begun with gentamicin alone or 0.3% polymyxin B alone, and in combination with acetylcysteine, 0.3M edetate disodium, and 2.500 units/ml of heparin sodium, four times daily. We also compared topical colistin and colistin and topical heparin. After two weeks, those corneas treated with polymyxin B and topical heparin showed a reduction in ulceration, corneal thinning, and descemetocele formation compared to those treated with polymyxin B alone. Based on these studies, heparin was administered topically, four times daily, to three patients with Pseudomonas-induced corneal ulcers in addition to antibiotics. Before treatment all corneas showed evidence of corneal liquefaction and two of the corneas were in imminent danger of perforation. After therapy, no corneas perforated; one patient recovered visual acuity of 6/9 (20/30), one patient recovered visual acuity of 6/6 (20/20) after keratoplasty, and the third has a vascularized leukoma.
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Emergency treatment of bites and stings. 2. Human bites. J Emerg Nurs 1976; 2:21-4. [PMID: 796510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Magnetic and optical studies of chromium oxides. Part 1.—Calcination of chromium trioxide supported on alumina. ACTA ACUST UNITED AC 1970. [DOI: 10.1039/tf9706601004] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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