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1.
J Clin Neurol ; 19(6): 547-557, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37488956

ABSTRACT

BACKGROUND AND PURPOSE: The importance of the quality of life (QOL) of carers has been increasingly recognized as it has a wide range of effects on the psychological, emotional, and social outcomes of patients with Parkinson's disease (PD). Understanding their QOL is important as it reflects their unique characteristics; however, there have been few studies on this in Korea. This study aimed to translate and validate the Korean version of the Parkinson's Disease Questionnaire-Carer (PDQ-Carer). METHODS: This was a methodological study that included a translation process and a cross-sectional investigation. The Korean version of the scale was developed using back translation, semantic adjustment, and pretests. The final version was self-administered by 125 Korean family carers. Cronbach's alpha values were used to assess the internal consistency of the PDQ-Carer. Exploratory and confirmatory factor analyses were used to validate the translated scale. RESULTS: Exploratory factor analysis identified four factors that accounted for 64.51% of the variance. A modified model using modification indices was found to fit the data well in the confirmatory factor analysis. That factor analysis supported the structure of the original four factors with relocation of several items that reflected Korean culture. Cronbach's alpha values were 0.96 for the total scale, 0.93 for personal and social activities, 0.89 for strain, 0.85 for anxiety and depression, and 0.85 for self-care. CONCLUSIONS: This study verified that the Korean version of the PDQ-Carer can be used to acquire important information about the multidimensional aspects of the QOL of Korean carers for patients with PD.

2.
J Adv Nurs ; 79(7): 2429-2443, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37077151

ABSTRACT

AIM: To understand how researchers applied the Tilburg Frailty Indicator (TFI) to older adults. The use of the TFI was examined based on the Integral Conceptual Model of Frailty (ICMF). DESIGN: A scoping review. DATA SOURCES: A database search was conducted without a time limit in PubMed, CINAHL, Embase and the Cochrane library. A hand search was also conducted. REVIEW METHODS: Research questions were developed based on the population-concept-context framework suggested by the Joanna Briggs Institute (2017). Studies were included if topics were related to the use of the TFI or ICMF and designs were longitudinal studies. RESULTS: A total of 37 studies met the inclusion criteria. Studies were reviewed according to the tested pathways of the ICMF: determinants of frailty or adverse outcomes, adverse outcomes of frailty and comparison of predictive power between frailty measures. CONCLUSION: The TFI is a useful tool to screen for frailty and predict health outcomes in older adults. Among the pathways of the ICMF, relationships between social factors and frailty were reported in several studies. Despite this relationship, social factors were considered as items to assess the social domain of frailty rather than determinants of frailty. The predictive power of the TFI was not superior to other frailty measures, but it had a high sensitivity. IMPACT: This study demonstrates the usability of the TFI in older adults living in various conditions. Further studies are required to identify more effective ways to screen frailty using the TFI. PATIENT OR PUBLIC CONTRIBUTION: No patient or public involvement in this study.


Subject(s)
Frailty , Humans , Aged , Frailty/diagnosis , Frail Elderly , Surveys and Questionnaires , Geriatric Assessment , Psychometrics , Longitudinal Studies
3.
Plast Reconstr Surg ; 150(6): 1314e-1321e, 2022 12 01.
Article in English | MEDLINE | ID: mdl-36161795

ABSTRACT

BACKGROUND: The elevator muscles of the upper lip are the levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus minor muscles, which function by means of their insertions into the skin of the upper lip. However, many textbooks and journal articles state that no muscle fibers are present on the orbicularis oris muscle in the upper lip. The authors attempted to determine whether there is a superficial muscle layer in addition to the orbicularis oris muscle in the upper lip. METHODS: The authors performed gross dissections of 10 formalin-fixed cadavers and applied micro-computed tomography to six formalin-fixed cadavers. The fine dissection of the upper lip was performed in a layer-by-layer manner that elucidated its muscle layers. The entire layer of the upper lip was separated and pretreated with phosphotungstic acid for micro-computed tomography. The samples used for micro-computed tomography were repurposed for use in histologic analysis. An ultrasonography study was also performed. RESULTS: The presence of a muscle layer on the orbicularis oris muscle was confirmed in all samples. The elevator muscle fibers of the upper lip formed a layer by combining with connective tissue. Micro-computed tomography indicated lower terminal insertions of the elevator muscles throughout the upper lip. All parts of the upper lip skin were inserted into the orbicularis oris muscle. The histologic findings were similar to those of micro-computed tomography. CONCLUSION: The authors' findings could be used to improve aesthetic and surgical procedures performed on the upper lip, such as correction of gummy smile and transverse upper labial crease, or postresection reconstruction of the upper lip.


Subject(s)
Esthetics, Dental , Lip , Humans , Lip/surgery , X-Ray Microtomography , Smiling , Gingiva , Facial Muscles/surgery , Cadaver , Formaldehyde
4.
Clin Anat ; 35(8): 1142-1146, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35811399

ABSTRACT

The facial artery is the main artery supplying blood to the face and is known to have facial branches of the inferior labial, superior labial, lateral nasal and angular arteries. These known major branches of facial artery run medially, however, there are sometimes branches of the facial artery heading laterally. The purpose of the present study was to investigate the lateral branches of the facial artery in face. We dissected facial branches of the facial artery in 74 cadaveric hemifaces. We investigated the presence of the lateral branches of the facial artery. Following parameters were investigated: lateral branch presence, the location of its origin, and the lateral branch diameter. Among the lateral branches, we evaluated the prevalence and diameter of the premasseteric branch. Lateral branches were observed in 48 of the 74 hemifaces (64.9%). The total number was 81 in the 48 hemifaces. The most common origin was between the inferior border of the mandible and inferior labial artery origin (42 of 81, 51.9%). The mean diameter of all lateral branches of the facial artery was 0.7 mm. Among the lateral branches, the premasseteric branches were present in 38 of 74 specimen (51.4%) and the mean diameter was 0.8 mm. The lateral branches of the facial artery may be registered in Terminologia Anatomica based on their prevalence. Accurate knowledge of the anatomy of the lateral branches of the facial artery is helpful for clinicians to avoid complications during facial procedures or maxillofacial surgeries.


Subject(s)
Face , Nose , Coronary Vessels , Face/blood supply , Humans , Mandible , Nose/blood supply
5.
Anat Cell Biol ; 55(2): 142-147, 2022 Jun 30.
Article in English | MEDLINE | ID: mdl-35773217

ABSTRACT

The frontal sinus is one of the four paranasal sinuses in humans, and knowledge of its anatomy is important when performing surgery involving the frontal bone or sinus. Although many studies have measured the frontal sinus using radiography and computed tomography (CT), few studies have evaluated by using three-dimensional (3D) analysis. The purpose of this study was to analyze the frontal sinus using 3D reconstruction analysis and determine the differences in linear and volumetric measurements between sexes, sides, and ages. The sample comprised 281 facial CT scans: 173 and 108 from males and females, respectively. The width, height, and length of each frontal sinus and total volume were all larger in males than in females. Almost all linear and volumetric measurements were larger in young adults than in older for both sexes, but not all of the differences were statistically significant. Linear and volumetric measurements were larger for males than females regardless of age group. There were no statistically significant differences between the right and left sides except the width in males. The size of the frontal sinus was strongly influenced by sex and age. The measurements reported here might be useful for improving surgical procedures involving the frontal sinus.

6.
Sci Rep ; 12(1): 6713, 2022 04 25.
Article in English | MEDLINE | ID: mdl-35468923

ABSTRACT

Older adults commonly experience concurrent lower handgrip strength and sensory impairment. However, previous studies have analyzed the individual effects of either handgrip strength or sensory impairment on cognitive impairment. To address this gap, this study investigated the combined effects of handgrip strength and sensory impairment on cognitive impairment among older adults. In total, 2930 participants aged 65 and older were analyzed using 2014-2018 data from the Korean Longitudinal Study of Aging. Participants underwent assessments of handgrip strength (grip dynamometer), sensory impairment (self-reported responses), and cognitive impairment (Korean version of the Mini-Mental State Examination). Low handgrip strength, compared to normal handgrip strength, was associated with cognitive impairment. In participants with low handgrip strength, vision and hearing impairment were associated with cognitive impairment (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.06-1.75; OR 2.58, 95% CI 1.77-3.78, respectively) compared to those with normal handgrip strength. Participants with low handgrip strength and dual sensory impairment had the highest OR for cognitive impairment (OR 3.73, 95% CI 2.65-5.25). Due to the strong association of low handgrip strength and dual sensory impairment with cognitive impairment, people living with low handgrip strength and dual sensory impairment should be classified as a high-risk group for cognitive impairment and should be prioritized for interventions.


Subject(s)
Cognitive Dysfunction , Hand Strength , Aged , Cognitive Dysfunction/diagnosis , Hand Strength/physiology , Humans , Hypesthesia , Longitudinal Studies , Prevalence , Republic of Korea/epidemiology
7.
J Adv Nurs ; 78(7): 2085-2094, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34990022

ABSTRACT

AIMS: Frailty is a leading cause of deteriorating physical function of older adults with osteoarthritis. This study examined a model of frailty with the goals of (1) exploring the direct effect of osteoarthritic symptoms on disability and the mediating effect of frailty on disability and (2) determining whether both effects are moderated by physical resilience. DESIGN: A cross-sectional descriptive study. METHODS: Data collection was conducted among patients 65-92 years of age (N = 235) who visited primary medical centres for the management of chronic arthritic pain between July and December 2019. Participants completed a questionnaire measuring osteoarthritic symptoms, frailty, physical resilience, and disability. SPSS 25.0 was used to analyse the conditional process model. This study was reported following the STROBE guidelines. RESULTS: Frailty was shown to be a mediator between osteoarthritic symptoms and disability. Furthermore, physical resilience played a role as a moderator in both the direct and indirect pathways of this mediating relationship. CONCLUSION: The findings emphasize the detrimental effects of osteoarthritic symptoms on disability through frailty, and the moderated mediation results suggest that these effects were conditional on physical resilience, which is a modifiable internal resource of individuals. When planning nursing interventions for older adults with osteoarthritis, nurses need to consider physical resilience as a moderator to prevent frailty and disability.


Subject(s)
Disabled Persons , Frailty , Osteoarthritis , Aged , Cross-Sectional Studies , Frail Elderly , Frailty/prevention & control , Humans , Surveys and Questionnaires
8.
J Craniofac Surg ; 33(4): 1241-1244, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-34739451

ABSTRACT

ABSTRACT: The zygomatico-orbital artery (ZOA) originating from the superficial temporal artery and supplying the lower temporal region superficially has been reported. Previous studies of this artery have used definitions that are too ambiguous for the results to be directly adapted to clinical practice, including since they have resulted in marked variations in the reported incidence ofthe artery. This study dissected 193 hemifaces of 123 fixed human cadavers aged 36 to 102 years (119 males and 74 females). The authors investigated the ZOA based on the following definition: (1) it originates from the superficial temporal artery, (2) it runs mostly above the zygomatic arch, and (3) it terminates below the superior border of the orbicularis oculi muscle. The incidence of the ZOA was 22.8% (44 cases of 193 sides), and its mean diameter was 1.1 mm. The meanvertical distances from the superior borderofthe zygomatic arch to the artery were 29.6, 17.8, and 2.9 mm at the jugale, zygion, and the origin of the ZOA, respectively. An accurate definition of the ZOA and accurate knowledge of its incidence and course could be important for clinicians to avoid unintentional complications in clinical practice.


Subject(s)
Head , Zygoma , Arteries , Cadaver , Female , Humans , Male , Temporal Arteries , Zygoma/anatomy & histology
9.
J Craniofac Surg ; 33(1): 333-336, 2022.
Article in English | MEDLINE | ID: mdl-34292252

ABSTRACT

ABSTRACT: The present study is to identify primarily the morphological characteristics in the growth proportion of the head and face for young Korean (8-24 years) and compare the magnitude of growth changes to the sex-related differences. Total 1255 were divided into 3 age groups: childhood (8-10 years), adolescence (14-16 years), and young adult (20-24 years). The anthropometric assessments were performed with 11 landmarks on the head and facial dimensions. The standardized frontal and lateral head and face photographs were analyzed the craniofacial growth proportions and morphological features for the comparison of both sexes. The noteworthy differences of anthropometric measurements between sexes with growing were noted on the lower head height (22.6%, 17.8%), midface height (22.0%, 19.6%), lower face height (23.5%, 14.7%), and face length (21.1%, 14.9%), face breadth (14.8%, 11.3%) of males and females, respectively. Whereas the upper head height (7.9%, 6.0%) and upper face height (4.2%, 0%, respectively) were less growing features. The most remarkable changes are the dimension of midface height and lower face height in both sexes. The present study could demonstrate a fundamental example to elucidate the sex-related dimensional differences for the analysis of the growth proportion of both sexes in Koreans.


Subject(s)
Face , Head , Adolescent , Anthropometry , Asian People , Cephalometry , Child , Face/anatomy & histology , Female , Head/anatomy & histology , Humans , Male , Republic of Korea , Young Adult
10.
Plast Reconstr Surg ; 147(6): 1321-1328, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34019502

ABSTRACT

BACKGROUND: Retrobulbar filler injection has recently been considered an ideal method for orbital volume enhancement due to its nontoxic, easily reversible, and noninvasive characteristics. This study determined the arterial distribution in the orbit with the aim of defining a safety zone for retrobulbar filler injections used to enhance the orbital volume. METHODS: Twenty-seven orbits of 24 formalin-embalmed cadavers were dissected. The orbital arteries were identified after removal of the eyeball, extraocular muscles, and connective tissues. The course of each orbital artery was then recorded in each specimen, and all of the courses were then superimposed to determine the arterial distribution in the orbit. RESULTS: The superimposition of lined images based on the orbital vasculature of each specimen revealed that the arterial density was highest in the superonasal region and lowest in the inferotemporal region. In particular, orbital arteries were scarce at 8 o'clock and 4 o'clock in the right and left orbits, respectively, and an artery-free zone was demonstrated in the outer part of those directions. CONCLUSIONS: When performing a transcutaneous retrobulbar injection of filler for orbital volume enhancement, the relative safety zone could be considered to be located at 8 o'clock and 4 o'clock in the right and left orbits, respectively. The detailed topographic information about the arterial distribution in the orbit, provided by the present study, may help oculofacial surgeons to avoid injury to major vessels and decrease the risk of retrobulbar hemorrhage and vision-threatening complications.


Subject(s)
Dermal Fillers/administration & dosage , Orbit/blood supply , Rejuvenation , Adult , Aged , Aged, 80 and over , Cadaver , Dermal Fillers/adverse effects , Female , Humans , Injections , Male , Middle Aged
11.
J Plast Reconstr Aesthet Surg ; 74(7): 1615-1620, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33303411

ABSTRACT

BACKGROUND: Volumetric rejuvenation of the dorsum of the hand with fat grafting or injectable fillers has increased in popularity in recent years. It has become widely accepted that the dorsum of the hand contains three fatty laminae: superficial, intermediate, and deep laminae. The dorsal venous plexus and dorsal cutaneous nerves are known to reside in the dorsal intermediate lamina. However, the superficial vein and cutaneous nerve might not be located in the same layer of subcutaneous tissue, as is the case in other body regions. MATERIALS AND METHODS: Eight hands were dissected in a layer-by-layer fashion from the skin to the extensor tendons. In another 13 hands from among 21 investigated cadavers, samples from the dorsum of the hand were harvested and stained using trichrome stains for histologic analysis. B-mode ultrasound was also performed for identifying structures of the dorsum of the hand. RESULTS: Anatomic dissection and histologic analysis of the dorsum of the hand revealed the presence of an unknown fascia in addition to the three known fascial layers. The additional fascia was located in the dorsal intermediate lamina and separated it into two compartments: one containing the dorsal venous plexus superficially and the other containing the dorsal cutaneous nerves deeply. Ultrasound showed corresponding structures including three hyperechoic fascial layers, three hypoechoic laminae, and additional hyperechoic fascia in dorsal intermediate lamina. CONCLUSIONS: Accurate anatomic knowledge of the dorsum of the hand will help practitioners determine the optimal and safe locations for performing fat grafting and injecting dermal fillers.


Subject(s)
Cosmetic Techniques , Hand/anatomy & histology , Rejuvenation , Aged , Aged, 80 and over , Fascia/anatomy & histology , Fascia/diagnostic imaging , Female , Hand/diagnostic imaging , Humans , Male , Middle Aged , Skin/anatomy & histology , Skin/diagnostic imaging , Skin/innervation , Ultrasonography , Veins/anatomy & histology , Veins/diagnostic imaging
12.
J Plast Reconstr Aesthet Surg ; 74(4): 866-873, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33214113

ABSTRACT

BACKGROUND: Hand rejuvenation has become increasingly popular in esthetic medicine. Hand rejuvenation with injectables remains challenging, and there are no established practice guidelines. The calcium hydroxylapatite (CaHA) filler injection is currently one of the most common procedures. This study aimed to identify the layer of the hand dorsum that is lifted by skin pinching and to identify the layer where an injectable filler would be placed based on the anatomical study and ultrasound findings. METHODS: The anatomic layers of the cadaveric hands were examined using the skin pinching method. Anatomic dissections and histological examinations were performed on four fixed and five fresh cadaveric hands to reveal the anatomical layers in which the CaHA filler was administered. Furthermore, 20 patients were treated with the CaHA filler, and the Doppler ultrasound was used to reveal the proper anatomical layers for filler placement. RESULTS: The study of the cadaveric hands showed that skin pinching can ensure safe entry points and can guide the cannula into safe planes without compromising the large superficial veins. A filler injection with skin pinching in cadaveric hands demonstrated that the filler was introduced primarily in the dorsal intermediate lamina where the veins are present. This was further confirmed by ultrasound findings. CONCLUSION: The dorsal intermediate lamina, which has the veins is a relatively loose structure, and the cannula was moved along this space. When the layer is stretched by skin pinching, the veins run underneath. The dorsal intermediate lamina is the appropriate layer to inject the filler.


Subject(s)
Cosmetic Techniques , Dermal Fillers/administration & dosage , Durapatite/administration & dosage , Esthetics , Hand , Cadaver , Humans , Injections , Rejuvenation , Skin Aging
13.
J Anat ; 237(6): 1006-1014, 2020 12.
Article in English | MEDLINE | ID: mdl-33085100

ABSTRACT

The seminal vesicles are the glands of male reproductive organs that produce the fluid and nutrient constituents of semen. It has been believed for a long time that the lumen of a seminal vesicle was a single-coiled tubular structure with irregular diverticula. There are several previous reports on the symmetry, differences in morphological sizes and classification of the seminal vesicles. However, a three-dimensional-coiled tubular structure is difficult to understand using a classical anatomical methodology, and hence, three-dimensional reconstruction is needed to understand the structure of the lumen. Thirty-one seminal vesicles harvested from 21 formalin-embalmed cadavers were investigated. The seminal vesicle along with the ampulla of the ductus deferens was separated, and the length and width of each seminal vesicle were measured. The vesicles were then embedded in coloured paraffin, and the resulting paraffin block was sectioned transversely and photographed at an interval of 500 µm, with the sectioned surfaces then utilized in three-dimensional reconstruction performed by 'Reconstruct' software. The mean length and width of the seminal vesicles were 39.4 mm and 13.4 mm, respectively, and the right seminal vesicle was a little larger than the one on the left. The size differed from previous reports, while the luminal structure was similar to the classification of Aboul-azm (Archives of Andrology, 3, 1979, 287-292) but differed from that of Pereira (AJR. American Journal of Roentgenology, 69, 1953, 361-379). The seminal vesicles typically comprised about 9 curls and had about 12 diverticula. The seminal vesicles resembled a skein of coral rather than comprising a single strand. These findings will help in improving the understanding of pathophysiologies of the seminal vesicles, such as recurrent inflammation of the gland.


Subject(s)
Image Processing, Computer-Assisted , Seminal Vesicles/anatomy & histology , Aged , Aged, 80 and over , Humans , Imaging, Three-Dimensional , Male , Seminal Vesicles/diagnostic imaging
14.
Surg Radiol Anat ; 42(10): 1255-1257, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32444934

ABSTRACT

The iliacus muscle is a large, flat, triangle-shaped muscle located in the iliac fossa. This muscle forms part of the iliopsoas muscle complex. Although anatomical variations of iliacus muscles are rare, some variations are clinically important due to the possible coexistence of an unusual course of the femoral nerve. The femoral nerve is the largest branch of the lumbar plexus and supplies the muscles and skin in the anterior aspect of the thigh. We encountered a case of a single aberrant slip of the iliacus muscle piercing the femoral nerve in the left iliac fossa of a male cadaver aged 97 years. The potential clinical importance of this variant iliacus muscle accompanied by a femoral nerve split would be femoral neuropathy and possible consequent alterations of sensation in the anterior and medial aspects of the thigh or motor deficit of the quadriceps muscle.


Subject(s)
Anatomic Variation , Femoral Nerve/abnormalities , Femoral Neuropathy/etiology , Muscle, Skeletal/abnormalities , Nerve Compression Syndromes/etiology , Aged, 80 and over , Cadaver , Humans , Ilium/innervation , Male
15.
Anat Cell Biol ; 53(1): 21-26, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32274245

ABSTRACT

Frankfort horizontal line, the line passing through the orbitale and porion, is one of the most widely used intracranial landmarks in cephalometric analysis. This study investigated the use of the orbito-occipital line extending from the orbitale to the external occipital protuberance as a novel horizontal line of the skull for substituting the Frankfort horizontal line. We evaluated the reproducibility of the new landmark and measured the angle between the orbito-occipital line and the Frankfort line. This study was conducted on 170 facial computed tomography (CT) scans of living adults from the Department of Plastic Surgery. After three-dimensionally reconstructed images were obtained from facial CT, the porion, orbitale, and external occipital protuberance were indicated by two observers twice. The angles between the orbito-meatal line (inferior orbital rim to porion; the Frankfort line) and the orbito-occipital line (inferior orbital rim to external occipital protuberance) were measured. There was no significant intraobserver or interobserver bias. The overall angle between the Frankfort line and orbito-occipital line was -0.5°±2.2° (mean±standard deviation). There was no statistically significant difference among side and sex. This study demonstrated good reproducibility of a new landmark-the external occipital protuberance-tested to replace the porion. The orbito-occipital line is a reliable, reproducible, and easily identifiable line, and has potential as a novel standard horizontal line to replace or at least supplement the Frankfort line in anthropological studies and certain clinical applications.

16.
J Plast Reconstr Aesthet Surg ; 73(6): 1130-1134, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32115380

ABSTRACT

BACKGROUND: The deep temporal fascia (DTF) is known to separate into two layers that descend to attach to the zygomatic arch. When surgeons reduce an isolated fracture of the zygomatic arch through a temporal approach, the temporal incision site needs to be superior to the split line of the DTF. MATERIALS AND METHODS: Sixty-seven hemifacial cadavers were investigated after removing the skin, subcutaneous tissue, and superficial temporal fascia. The superficial layer of the DTF was exposed. We cut the superficial layer along the line along, which it adhered to the deep layer inseparably. The heights of the split line of the DTF from the superior border of the zygomatic arch and from the top of the helix were measured at three points: at the jugale, zygion, and 3 cm from the tragus. RESULTS: In all cases there were thick identifiable deep layers of the DTF. The mean heights of the split line of the DTF from the superior border of the zygomatic arch were 49.8, 46.7, and 42.6 mm at the jugale, zygion, and 3 cm from the tragus, respectively; the corresponding mean heights of the split line from the top of the helix were 19.1, 15.6, and 11.4 mm. CONCLUSIONS: Knowledge of the mean height of the split line of the DTF will be helpful for surgeons to determine the temporal incision site for ensuring the safe reduction of a zygomatic arch fracture.


Subject(s)
Temporal Muscle/surgery , Zygoma/injuries , Zygomatic Fractures/surgery , Aged , Aged, 80 and over , Cadaver , Closed Fracture Reduction/methods , Fascia/anatomy & histology , Fasciotomy/methods , Female , Humans , Male , Middle Aged , Temporal Muscle/anatomy & histology , Zygoma/surgery
17.
Am J Physiol Cell Physiol ; 289(2): C425-36, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15800051

ABSTRACT

The action of cytochalasins, actin-disrupting agents on human Kv1.5 channel (hKv1.5) stably expressed in Ltk(-) cells was investigated using the whole cell patch-clamp technique. Cytochalasin B inhibited hKv1.5 currents rapidly and reversibly at +60 mV in a concentration-dependent manner with an IC(50) of 4.2 microM. Cytochalasin A, which has a structure very similar to cytochalasin B, inhibited hKv1.5 (IC(50) of 1.4 microM at +60 mV). Pretreatment with other actin filament disruptors cytochalasin D and cytochalasin J, and an actin filament stabilizing agent phalloidin had no effect on the cytochalasin B-induced inhibition of hKv1.5 currents. Cytochalasin B accelerated the decay rate of inactivation for the hKv1.5 currents. Cytochalasin B-induced inhibition of the hKv1.5 channels was voltage dependent with a steep increase over the voltage range of the channel's opening. However, the inhibition exhibited voltage independence over the voltage range in which channels are fully activated. Cytochalasin B produced no significant effect on the steady-state activation or inactivation curves. The rate constants for association and dissociation of cytochalasin B were 3.7 microM/s and 7.5 s(-1), respectively. Cytochalasin B produced a use-dependent inhibition of hKv1.5 current that was consistent with the slow recovery from inactivation in the presence of the drug. Cytochalasin B (10 microM) also inhibited an ultrarapid delayed rectifier K(+) current (I(K,ur)) in human atrial myocytes. These results indicate that cytochalasin B primarily blocks activated hKv1.5 channels and endogenous I(K,ur) in a cytoskeleton-independent manner as an open-channel blocker.


Subject(s)
Actins/drug effects , Cytochalasins/pharmacology , Potassium Channels, Voltage-Gated/drug effects , Animals , Dose-Response Relationship, Drug , Humans , Kv1.5 Potassium Channel , Membrane Potentials/drug effects , Mice , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Patch-Clamp Techniques , Potassium Channels, Voltage-Gated/metabolism , Time Factors , Transfection
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