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2.
AIDS Res Hum Retroviruses ; 36(3): 176-179, 2020 03.
Article in English | MEDLINE | ID: mdl-31813226

ABSTRACT

The Martin-Hopkins equation used to calculate low-density lipoprotein cholesterol (LDL-C) is more accurate than the traditional Friedewald equation, especially at higher triglyceride levels, which are more common in people with HIV (PWH). Thus, using LDL-C values calculated by the Martin-Hopkins equation may improve clinical care of PWH.


Subject(s)
Cholesterol, LDL/blood , HIV Infections/blood , Aged , HIV Infections/complications , Humans , Hypertriglyceridemia/blood , Hypertriglyceridemia/etiology , Male , Middle Aged , Risk Assessment
3.
Sr Care Pharm ; 34(3): 206-214, 2019 Mar 01.
Article in English | MEDLINE | ID: mdl-31155027

ABSTRACT

AIM: The most frequent use of medications in the geriatric population occurs in skilled nursing facilities. This quality assurance study prospectively examines the high number of prescriptions ordered for long-term nursing facility residents throughout their first year after admission. METHODS: The investigators prospectively followed 101 consecutive long-term-stay older adult residents at the Joyce Eisenberg Keefer Medical Center, a nursing facility of Los Angeles Jewish Home for the Aging (LAJH) over a 12-month period. Preadmission prescriptions were obtained for 91 residents, as well as prescriptions at 1 week, 1 month, 3 months, 6 months, and 1 year after admission. The number of prescriptions by staff physicians and outside physicians was examined. RESULTS: Over the 12 months following admission, the mean number of scheduled prescriptions increased significantly from 11.1 prior to admission to 13.0 by 6 months and to 13.3 by 12 months (P-value < 0.05). The residents who were hospitalized during the 12 months of observation received significantly more scheduled, as needed, and total prescriptions than those not hospitalized. Physicians employed full time by LAJH ordered significantly fewer additional prescriptions than physicians with outside practices. The patients of the staff physicians also had fewer hospitalizations than those of the outside physicians. CONCLUSION: This quality assurance study reveals a statistically significant increase in the number of prescriptions made in a long-term care setting over a 12-month prospective study. Patients of staff physicians received fewer prescriptions and were hospitalized less frequently than patients of physicians who practiced outside LAJH.


Subject(s)
Long-Term Care , Nursing Homes , Aged , Humans , Los Angeles , Prospective Studies , Skilled Nursing Facilities
4.
Open Forum Infect Dis ; 6(12): ofz474, 2019 Dec.
Article in English | MEDLINE | ID: mdl-32128324

ABSTRACT

OBJECTIVE: Low HDL cholesterol (HDL-C) is common in people living with HIV infection, which is associated with inflammation, and correlates with greater cardiovascular disease (CVD) risk. Particles of HDL are HDL subfractions, and in some general population studies, higher small HDL particle number (HDL-P) has been associated with lower CVD risk. The objective of this study was to determine whether HIV serostatus and systemic inflammation were associated with small HDL-P in the Multicenter AIDS Cohort Study (MACS). METHOD: The MACS is composed of HIV-infected and HIV-uninfected men. Separate linear regression analyses were conducted to evaluate the associations between outcomes (small HDL-P, large HDL-P, total HDL-P, and HDL size) and variables of interest (interleukin-6 [IL-6], D-dimer, and intercellular adhesion molecule-1 [ICAM-1] levels), with adjustment for other CVD risk factors. RESULTS: The study population included 553 HIV-infected (88.1% on current ART) and 319 HIV-uninfected men. The mean age was 52.7 years for HIV-infected men and 55.3 years for HIV-uninfected men. In separate models of the study population, higher log IL-6 was associated with lower total and small HDL-P (P < .01 for both), independent of HIV serostatus and CVD risk factors. Similar results were seen with ICAM-1. Positive HIV serostatus was associated with lower small and total HDL-P, adjusted for inflammatory markers. CONCLUSIONS: Greater systemic inflammation and HIV infection both were associated with lower atheroprotective small HDL-P. This may be a potential mechanism contributing to increased cardiovascular risk among HIV-infected people.

5.
Nutrients ; 10(11)2018 Oct 26.
Article in English | MEDLINE | ID: mdl-30373159

ABSTRACT

Cataract is an eye disease with clouding of the eye lens leading to disrupted vision, which often develops slowly and causes blurriness of the eyesight. Although the restoration of the vision in people with cataract is conducted through surgery, the costs and risks remain an issue. Botanical drugs have been evaluated for their potential efficacies in reducing cataract formation decades ago and major active phytoconstituents were isolated from the plant extracts. The aim of this review is to find effective phytoconstituents in cataract treatments in vitro, ex vivo, and in vivo. A literature search was synthesized from the databases of Pubmed, Science Direct, Google Scholar, Web of Science, and Scopus using different combinations of keywords. Selection of all manuscripts were based on inclusion and exclusion criteria together with analysis of publication year, plant species, isolated phytoconstituents, and evaluated cataract activities. Scientists have focused their attention not only for anti-cataract activity in vitro, but also in ex vivo and in vivo from the review of active phytoconstituents in medicinal plants. In our present review, we identified 58 active phytoconstituents with strong anti-cataract effects at in vitro and ex vivo with lack of in vivo studies. Considering the benefits of anti-cataract activities require critical evaluation, more in vivo and clinical trials need to be conducted to increase our understanding on the possible mechanisms of action and the therapeutic effects.


Subject(s)
Cataract/prevention & control , Phytochemicals/pharmacology , Plant Extracts/pharmacology , Humans , Phytochemicals/chemistry , Plant Extracts/chemistry
6.
Clin Interv Aging ; 13: 1071-1077, 2018.
Article in English | MEDLINE | ID: mdl-29881263

ABSTRACT

A 12-week study was conducted in eight dementia care communities involving 77 participants addressing the hypothesis that an intervention of increasing indoor exposure to daylight will reduce depression and other neuropsychiatric symptoms. At four communities, staff were enlisted to increase daylight exposure by taking participants to a perimeter room with daylight exposure for socialization in the morning (8:00-10:00 AM) each day. At the other four communities, a control group were taken to a similar sized area without daylight for socialization under typical electrical lighting conditions. Participants in the daylight intervention experienced an average decrease over the trial in the Neuropsychiatric Inventory Nursing Home Version (NPI-NH) scores (p=0.33) and the Cornell Scale for Depression in Dementia (CSDD) scores (p=0.025), while the control participants showed average but nonsignificant increases in both NPI-NH (p=0.33) and CSDD (p=0.13). Difference in outcome changes of the intervention group achieved statistical significance for CSDD (p=0.01) but not for NPI-NH (p=0.17). Our results suggest that increased exposure to daylight can reduce depression in people living with dementia.


Subject(s)
Dementia/psychology , Dementia/therapy , Depression/psychology , Depression/therapy , Nursing Homes , Phototherapy , Aged , Aged, 80 and over , Depressive Disorder , Female , Humans , Light , Long-Term Care , Male , Pilot Projects , Psychiatric Status Rating Scales
7.
Am J Bot ; 102(10): 1685-702, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26419810

ABSTRACT

PREMISE OF THE STUDY: A knowledge of pollen characters in early-diverging angiosperm lineages is essential for understanding pollen evolution and the role of pollen in angiosperm diversification. In this paper, we report and synthesize data on mature pollen and pollen ontogeny from all genera of Nymphaeales within a comparative, phylogenetic context and consider pollen evolution in this early-diverging angiosperm lineage. We describe mature pollen characters for Euryale, Barclaya, and Nymphaea ondinea, taxa for which little to no structural data exist. METHODS: We studied mature pollen for all nymphaealean genera using light, scanning electron, and transmission electron microscopy. We reviewed published reports of nymphaealean pollen to provide a comprehensive discussion of pollen characters in water lilies. KEY RESULTS: Nymphaeales exhibit diversity in key pollen characters, including dispersal unit size, ornamentation, aperture morphology, and tapetum type. All Nymphaeales pollen are tectate-columellate, exhibiting one of two distinct patterns of infratectal ultrastructure-a thick infratectal space with robust columellae or a thin infratectal space with thin columellae. All genera have pollen with a lamellate endexine that becomes compressed in the proximal, but not distal wall. This endexine ultrastructure supports the operculate hypothesis for aperture origin. Nymphaeaceae pollen exhibit a membranous granular layer, which is a synapomorphy of the family. CONCLUSIONS: Variation in pollen characters indicates that significant potential for lability in pollen development was present in Nymphaeales at the time of its divergence from the rest of angiosperms. Structural and ontogenetic data are essential for interpreting pollen characters, such as infratectum and endexine ultrastructure in Nymphaeales.


Subject(s)
Nymphaeaceae/anatomy & histology , Nymphaeaceae/growth & development , Pollen/anatomy & histology , Pollen/growth & development , Biological Evolution , Malaysia , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nymphaea/anatomy & histology , Nymphaea/classification , Nymphaea/growth & development , Nymphaea/ultrastructure , Nymphaeaceae/classification , Nymphaeaceae/ultrastructure , Phylogeny , Pollen/ultrastructure , Pollination , United States , Western Australia
8.
Int J Popul Stud ; 1(1): 19-28, 2015.
Article in English | MEDLINE | ID: mdl-28553664

ABSTRACT

The Japanese have the highest life expectancy in the world while the United States (U.S.) has relatively low life expectancy. Furthermore, the Americans have relatively poorer health compared to the Japanese. Examination of the treatment of specific conditions such as hypertension in these two countries may provide insights into how the health care system contributes to the relative health in these two countries. In this study, we focus on the treatment of hypertension, as this is the most common condition requiring therapeutic interventions in seniors. This study examines hypertension diagnoses and controls in nationally representative samples of the older populations (68 years-or-older) of Japan and the U.S. Data come from two nationally representative samples: the Nihon University Japanese Longitudinal Study of Aging (NUJLSOA) (n=2,309) and the U.S. Health and Retirement (HRS) Study (n=3,517). The overall prevalence of hypertension is higher in Japan than the U.S. Undiagnosed hypertension is about four times higher in Japan than in the U.S., while the control of blood pressure is more than four times higher in the U.S. than in Japan. Thus, the use of antihypertensive medication is much more frequent and more effective in the U.S. The medical care system seems to be more effective in controlling hypertension in the U.S. than in Japan. This may be due to the more aggressive diagnosis and treatment of hypertension in the U.S.

12.
Am J Bot ; 96(1): 207-15, 2009 Jan.
Article in English | MEDLINE | ID: mdl-21628184

ABSTRACT

SEM studies of xylem of stems of Nuphar reveal a novel feature, not previously reported for any angiosperm. Pit membranes of tracheid end walls are composed of coarse fibrils, densest on the distal (outside surface, facing the pit of an adjacent cell) surface of the pit membrane of a tracheid, thinner, and disposed at various levels on the lumen side of a pit membrane. The fibrils tend to be randomly oriented on the distal face of the pit membrane; the innermost fibrils facing the lumen take the form of longitudinally oriented strands. Where most abundantly present, the fibrils tend to be disposed in a spongiform, three-dimensional pattern. Pores that interconnect tracheids are present within the fibrillar meshwork. Pit membranes on lateral walls of stem tracheids bear variously diminished versions of this pattern. Pits of root tracheids are unlike those of stems in that the lumen side of pit membranes bears a reticulum revealed on the outer surface of the tracheid after most of the thickness of a pit membrane is shaved away by the sectioning process. No fibrillar texturing is visible on the root tracheid pits when they are viewed from the inside of a tracheid. Tracheid end walls of roots do contain pores of various sizes in pit membranes. These root and stem patterns were seen in six species representing the two sections of Nuphar, plus one intersectional hybrid, as well as in one collection of Nymphaea, included for purposes of comparison. Differences between root and stem tracheids with respect to microstructure are consistent in all species studied. Microstructural patterns reported here for stem tracheid pits of Nymphaeaceae are not like those of Chloranthaceae, Illiciaceae, or other basal angiosperms. They are not referable to any of the patterns reported for early vascular plants. The adaptational nature of the pit membrane structure in these tracheids is not apparent; microstructure of pit membranes in basal angiosperms is more diverse than thought prior to study with SEM.

13.
Am J Bot ; 93(7): 963-71, 2006 Jul.
Article in English | MEDLINE | ID: mdl-21642160

ABSTRACT

Xylem of the orchids studied provided unusually favorable material to demonstrate how conductive tissue evolves in monocotyledons. In the end walls of tracheary elements of many Orchidaceae, remnants of pit membranes were observed with scanning electron microscopy and minimally destructive methods. The full range from tracheids to vessel elements, featuring many intermediate stages, was illustrated with SEM in hand sections of fixed roots, stems, and inflorescence axes of 13 species from four subfamilies. Pit membranes in end walls of tracheary elements are porose to reticulate in roots of all species, but nonporose in stems of Cypripedioideae and Vanilloideae and porose to reticulate in stems of Orchidoideae and Epidendroideae. The distribution pattern of pit membranes and pit membrane remnants in end walls of tracheary elements of orchids parallels the findings of others. The position of Cypripedioideae and Vanilloideae as outgroups to Orchidoideae and Epidendroideae, claimed by earlier authors, is supported by clades based on molecular studies and by our studies. Little hydrolysis of pit membranes in tracheary element end walls was observed in pseudobulbs or inflorescence axes of epidendroids. The pervasiveness of network-like pit membranes of various extents and patterns in end walls of tracheary elements in Orchidaceae calls into question the traditional definitions of tracheids and vessel elements, not merely in orchids, but in angiosperms at large. These two concepts, based on light microscope studies, are blurred in light of ultrastructural studies. More importantly, the intermediate expressions of pit membranes in tracheary element end walls of Orchidaceae and some other families of angiosperms are important as indicators of steps in evolution of conduction with respect to organs (more rapid flow in roots than in succulent storage structures) and habitat (less obstruction to flow correlated with a shift from terrestrial to epiphytic).

14.
Am J Bot ; 91(12): 2022-9, 2004 Dec.
Article in English | MEDLINE | ID: mdl-21652351

ABSTRACT

Cryptic species are morphologically indistinguishable, yet reproductively isolated. Morphological boundaries between species can also be obscured by hybridization and clonality. Determining the roles of reproductive isolation, hybridization, and clonality in morphologically indistinguishable taxa is essential to determining appropriate species-level taxonomic rankings for conservation purposes. The taxonomic status of the endangered Little Aguja pondweed of west Texas, Potamogeton clystocarpus, is uncertain due to a lack of fixed morphological differences between it and two sympatric congeners. Morphology, amplified fragment length polymorphisms (AFLPs), and sequences of the internal transcribed spacer (ITS) region and trnL-F intron and spacer were used to determine the degree of genetic distinctiveness, hybridization and clonality for this rare species. AFLPs indicate that P. clystocarpus is a genetically distinct lineage compared to P. pusillus and P. foliosus. No hybrids involving P. clystocarpus were detected, but two putative hybrids involving P. pusillus and P. foliosus were identified. Clonal growth was only detected in P. pusillus. A combination of morphological and molecular markers was successful in determining the genetic distinctiveness of an endangered cryptic species, Potamogeton clystocarpus. Further sampling in this and adjacent drainages is necessary to assess the degree of endemism of P. clystocarpus and confidently rule out hybridization and clonality in this taxon.

15.
Am J Physiol Cell Physiol ; 286(3): C586-95, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14592811

ABSTRACT

In mildly hyperosmotic medium, activation of the Na+ -K+ -2Cl- cotransporter (NKCC) counteracts skeletal muscle cell water loss, and compounds that stimulate protein kinase A (PKA) activity inhibit the activation of the NKCC. The aim of this study was to determine the mechanism for PKA inhibition of NKCC activity in resting skeletal muscle. Incubation of rat slow-twitch soleus and fast-twitch plantaris muscles in isosmotic medium with the PKA inhibitors H-89 and KT-5720 caused activation of the NKCC only in the soleus muscle. NKCC activation caused by PKA inhibition was insensitive to MEK MAPK inhibitors and to insulin but was abolished by the PKA stimulators isoproterenol and forskolin. Furthermore, pinacidil [an ATP-sensitive potassium (KATP) channel opener] or inhibition of glycolysis increased NKCC activity in the soleus muscle but not in the plantaris muscle. Preincubation of the soleus muscle with glibenclamide (a KATP channel inhibitor) prevented the NKCC activation by hyperosmolarity, PKA inhibition, pinacidil, and glycolysis inhibitors. In contrast, glibenclamide stimulated NKCC activity in the plantaris muscle. In cells stably transfected with the Kir6.2 subunit of the of KATP channel, inhibition of glycolysis activated potassium current and NKCC activity. We conclude that activation of KATP channels in slow-twitch muscle is necessary for activation of the NKCC and cell volume restoration in hyperosmotic conditions.


Subject(s)
MAP Kinase Kinase Kinase 1 , Muscle Fibers, Slow-Twitch/physiology , Potassium Channels, Inwardly Rectifying/metabolism , Sodium-Potassium-Chloride Symporters/metabolism , Sulfonamides , Water-Electrolyte Balance/physiology , Adenosine Triphosphate/metabolism , Animals , Cell Line , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Cyclic AMP-Dependent Protein Kinases/metabolism , Enzyme Inhibitors/pharmacology , Female , Humans , Hypertonic Solutions/pharmacology , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Isoquinolines/pharmacology , Kidney/cytology , MAP Kinase Kinase Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Patch-Clamp Techniques , Potassium Channels, Inwardly Rectifying/genetics , Rats , Rats, Sprague-Dawley , Rubidium Radioisotopes , Transfection , Water/metabolism , Water-Electrolyte Balance/drug effects
16.
Am J Med ; 115(6): 441-7, 2003 Oct 15.
Article in English | MEDLINE | ID: mdl-14563500

ABSTRACT

BACKGROUND: Chinese herbal medicines are commonly used to improve general health and well-being despite limited scientific data to support their efficacy. We conducted a randomized, double-blind, placebo-controlled trial to determine whether an herbal remedy that is used widely in China was associated with changes in quality of life, energy, memory, sexual function, and qi (the Chinese concept of "vital energy" that is important in general health). METHODS: Residents (n = 237) of Beijing, China, who were aged > or =60 years and had self-reported decreased energy, memory, or sexual function, were randomly assigned to take four tablets of a Chinese herbal formula or of an identical placebo, three times a day for 30 days. Patients returned for one follow-up visit after 30 days for assessment of all outcomes. The main outcome measures were changes in quality of life at 30 days as measured by the 12-Item Short Form Health Survey (SF-12) Mental and Physical Component Summary scales. RESULTS: Use of Chinese herbs was associated with a small benefit in the Mental Component scale (difference of 1.9 points; 95% confidence interval [CI]: 0.1 to 3.6) and no benefit in the Physical Component scale (difference of -0.1 points; 95% CI: -1.7 to 1.5) as compared with placebo. A small improvement in the qi scale was no longer significant after adjusting for baseline differences in this score between groups. There was no improvement in physical performance, memory, or sexual function. The herbal product was well tolerated. CONCLUSION: Short-term use of a mixture of Chinese herbs was associated with a small benefit in one measure of mental health that is of unclear clinical importance.


Subject(s)
Drugs, Chinese Herbal/therapeutic use , Qi , Quality of Life , Aged , China , Double-Blind Method , Drugs, Chinese Herbal/adverse effects , Female , Follow-Up Studies , Health Status Indicators , Humans , Male , Memory , Mental Health , Sexuality , Time Factors
18.
Am J Physiol Regul Integr Comp Physiol ; 284(3): R655-65, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12433675

ABSTRACT

In isosmotic conditions, insulin stimulation of PI 3-K/Akt and p38 MAPK pathways in skeletal muscle inhibits Na(+)-K(+)-2Cl(-) cotransporter (NKCC) activity induced by the ERK1,2 MAPK pathway. Whether these signaling cascades contribute to NKCC regulation during osmotic challenge is unknown. Increasing osmolarity by 20 mosM with either glucose or mannitol induced NKCC-mediated (86)Rb uptake and water transport into rat soleus and plantaris skeletal muscle in vitro. This NKCC activity restored intracellular water. In contrast to mannitol, hyperosmolar glucose increased ERK1,2 and p38 MAPK phosphorylation. Glucose, but not mannitol, impaired insulin-stimulated phosphorylation of Akt and p38 MAPK in the plantaris and soleus muscles, respectively. Hyperosmolarity-induced NKCC activation was insensitive to insulin action and pharmacological inhibition of ERK1,2 and p38 MAPK pathways. Paradoxically, cAMP-producing agents, which stimulate NKCC activity in isosmotic conditions, suppressed hyperosmolar glucose- and mannitol-induced NKCC activity and prevented restoration of muscle cell volume in hyperosmotic media. These results indicate that NKCC activity helps restore muscle cell volume during hyperglycemia. Moreover, hyperosmolarity activates NKCC regulatory pathways that are insensitive to insulin inhibition.


Subject(s)
Body Water/metabolism , Muscle, Skeletal/metabolism , Protein Serine-Threonine Kinases , Sodium-Potassium-Chloride Symporters/physiology , Animals , Colforsin/pharmacology , Culture Media/chemistry , Culture Media/pharmacology , Cyclic AMP/metabolism , Enzyme Inhibitors/pharmacology , Female , Glucose/pharmacology , Insulin/pharmacology , Insulin/physiology , Intracellular Membranes/metabolism , Isoproterenol/pharmacology , Mannitol/pharmacology , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/physiology , Muscle, Skeletal/drug effects , Osmolar Concentration , Osmotic Pressure , Phosphorylation/drug effects , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Rats , Rats, Sprague-Dawley , Sodium Potassium Chloride Symporter Inhibitors , Solute Carrier Family 12, Member 2 , p38 Mitogen-Activated Protein Kinases
19.
J Gerontol A Biol Sci Med Sci ; 57(6): B239-46, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12023260

ABSTRACT

We examined the in vitro proliferative potential of 669 cell cultures established from skin biopsies of members of the Baltimore Longitudinal Study of Aging. The colony size distribution was used to estimate the proliferative life span of the cultures. A significant decline in proliferative potential with donor age was observed for female but not male donors. For both male and female donors, the proliferative potential was significantly greater for donors under the age of 30 years compared with all donors over the age of 30 years. In an attempt to reduce genetic heterogeneity, we examined the proliferative potential of cultures derived at different ages from the same donor. These studies revealed a trend (approaching statistical significance) toward low proliferative potential as donors aged. Interestingly, samples obtained from donors who had a history of skin cancer at the time of biopsy had a significantly lower doubling potential than those from donors who did not. The implications of these results for the use of cells derived from donors of different ages for aging research are discussed.


Subject(s)
Aging/pathology , Aging/physiology , Fibroblasts/pathology , Fibroblasts/physiology , Adult , Age Factors , Aged , Analysis of Variance , Biopsy, Needle , Cell Division/physiology , Cell Survival , Cells, Cultured , Female , Humans , In Vitro Techniques , Linear Models , Longitudinal Studies , Male , Middle Aged , Sensitivity and Specificity , Sex Factors , Skin/cytology
20.
Am J Bot ; 89(2): 185-95, 2002 Feb.
Article in English | MEDLINE | ID: mdl-21669726

ABSTRACT

Current definitions of tracheids and vessel elements are overly simple. These definitions are based on light microscope studies and have not incorporated information gained with scanning electron microscopy (SEM) or transmission electron microscopy (TEM). Current definitions are based primarily on angiosperms, especially eudicots, and were devised before many basal angiosperms were carefully studied. When all sources of information are taken into account, one can recognize changes in six characters in the evolution of tracheids into vessel elements in angiosperms (or vice versa) as well as in other groups of vascular plants. There is an appreciable number of taxa in which all criteria for vessel origin are not met, and thus incipient vessels are present. At the very least, vessel presence or absence should not be treated as a single binary character state change in construction of cladistic matrices. Increase in conductive area of an end wall by means of lysis of progressively greater areas of pit membrane and increase in pit area on the end wall (as compared to pit area on equivalent portions of lateral walls) are considered the most important usable criteria for recognizing intermediacy between tracheids and vessel elements. Primitive character states in vessel elements are briefly discussed to differentiate them from changes in character states that can be regarded as intermediate between tracheids and vessel elements.

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