Anterior Portion (anterior + portion)

Distribution by Scientific Domains


Selected Abstracts


Surgical Stent Fabrication for Unilateral Nasal Obstruction of the Anterior Portion of the Nasal Airway

JOURNAL OF PROSTHODONTICS, Issue 3 2009
Fong Wong BSD
Abstract A description is given of the indication and technical steps for fabricating a unilateral nasal stent to maintain patency of the nasal passage after surgical opening of an obstruction in a pediatric case. The methodology uses a two-step impression of the contralateral unobstructed naris and exterior valve region to generate a two-piece injection mold. The mold is used to fabricate a soft silicone-based anatomical stent. It supports an intranasal skin graft that was placed to reduce the risk of granulation. [source]


Development of the endoderm and gut in medaka, Oryzias latipes

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5 2006
Daisuke Kobayashi
We performed an extensive analysis of endodermal development and gut tube morphogenesis in the medaka embryo by histology and in situ hybridization. The markers used in these analyses included sox17, sox32, foxA2, gata-4, -5, -6 and shh. sox17, sox32, foxA2, and gata-5 and -6 are expressed in the early endoderm to the onset of gut tube formation. Sections of medaka embryos hybridized with foxA2, a pan-endodermal marker during gut morphogenesis, demonstrated that gut tube formation is initiated in the anterior portion and that the anterior and mid/posterior gut undergo distinct morphogenetic processes. Tube formation in the anterior endoderm that is fated to the pharynx and esophagus is much delayed and appears to be independent of gut morphogenesis. The overall aspects of medaka gut development are similar to those of zebrafish, except that zebrafish tube formation initiates at both the anterior and posterior portions. Our results therefore describe both molecular and morphological aspects of medaka digestive system development that will be necessary for the characterization of medaka mutants. [source]


Genetic mapping of Foxb1-cell lineage shows migration from caudal diencephalon to telencephalon and lateral hypothalamus

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2008
Tianyu Zhao
Abstract The hypothalamus is a brain region with vital functions, and alterations in its development can cause human disease. However, we still do not have a complete description of how this complex structure is put together during embryonic and early postnatal stages. Radially oriented, outside-in migration of cells is prevalent in the developing hypothalamus. In spite of this, cell contingents from outside the hypothalamus as well as tangential hypothalamic migrations also have an important role. Here we study migrations in the hypothalamic primordium by genetically labeling the Foxb1 diencephalic lineage. Foxb1 is a transcription factor gene expressed in the neuroepithelium of the developing neural tube with a rostral expression boundary between caudal and rostral diencephalon, and therefore appropriate for marking migrations from caudal levels into the hypothalamus. We have found a large, longitudinally oriented migration stream apparently originating in the thalamic region and following an axonal bundle to end in the anterior portion of the lateral hypothalamic area. Additionally, we have mapped a specific expansion of the neuroepithelium into the rostral diencephalon. The expanded neuroepithelium generates abundant neurons for the medial hypothalamus at the tuberal level. Finally, we have uncovered novel diencephalon-to-telencephalon migrations into septum, piriform cortex and amygdala. [source]


Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

JOURNAL OF ANATOMY, Issue 3 2006
Anthony J. Blazevich
Abstract Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps architecture show a gender difference in whole quadriceps muscle thickness, and that muscle thickness is positively correlated with fascicle angle whereas fascicle length is negatively, although weakly, correlated with fascicle angle. These results are supportive of the validity of estimates of whole quadriceps architecture. These data are interpreted with respect to their implications for neural control strategies, region-specific adaptations in muscle size in response to training, and gender-dependent differences in the response to exercise training. [source]


Preliminary rapport on head posture and muscle activity in subjects with class I and II

JOURNAL OF ORAL REHABILITATION, Issue 11 2005
I. C. GADOTTI
summary, Forward head posture may cause alterations in the stomatognathic system, including changes in the muscle activity of the masticatory muscles and dental occlusion alterations. Considering the need for further understanding of the relationship between the stomatognathic system and the cervical region, the purpose of this study was to analyse the head posture and the electromyographic (EMG) activity of the anterior portion of temporal and masseter muscles bilaterally among bruxist's subjects with different dental occlusion classifications using the Angle method. The study consisted of 20 female volunteers, between the ages of 17 and 27 years. They were separated into two groups (class I and class II occlusions) according to a dentist-performed evaluation. An assessment of forward head posture was conducted using a photographic technique (angular calculus) combined with a clinical analysis. In the EMG analyses, active differential surface electrodes (Ag) were utilized and were placed bilaterally on the belly of masseter and temporal muscles, perpendicular to the muscles fibres. The EMG signal recorded during bilateral isotonic mastication, was presented using the Root Mean Square and was processed by Matlab software. The results indicated that the EMG responses of temporal and masseter muscles tend to be modified by occlusion alteration class II. Subjects with class II occlusion tended to present more occurrence of forward head posture with alterations in the muscle activity pattern between masseter and temporal muscles. [source]


Hepatectomy of living donors with a left-sided gallbladder and multiple combined anomalies for adult-to-adult living donor liver transplantation

LIVER TRANSPLANTATION, Issue 1 2004
Shin Hwang
The left-sided gallbladder is very rare, but it is often accompanied by multiple anomalies of the liver, by which living donor hepatectomy cannot be feasible or becomes difficult. We have experienced 3 donors with a left-sided gallbladder out of 642 living donors. The first case was a male donor showing bifurcating portal anomaly with intrahepatic right portal vein confluence and extremely low bifurcation of the bile ducts. The right lobe was retrieved and implanted to his father. The second case was a male donor revealing trifurcating portal anomaly with separate right posterior portal branch and replacing right posterior hepatic artery. The right posterior segment graft was retrieved and implanted to his uncle. The third case was a male volunteer in whom the anterior portion of the medial segment was fed by an aberrant branch of the right anterior segment glisson. The small left lobe was retrieved and implanted simultaneously with another living donor's left lobe graft in the form of a dual living donor liver transplantation. There was no donor morbidity or recipient complication. Although there is a high possibility of diverse liver anomalies in living donors with a left-sided gallbladder, complete preoperative evaluation and mapping of the multiple anatomical variations may make certain types of living donor hepatectomy feasible. (Liver Transpl 2004;10:141,146.) [source]


Photochemistry and Photocytotoxicity of Alkaloids from Goldenseal (Hydrastis canadensis L.) 3: Effect on Human Lens and Retinal Pigment Epithelial Cells

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007
Colin F. Chignell
ABSTRACT The dried root or rhizome of Goldenseal (Hydrastis canadensis L.) contains several alkaloids including berberine, hydrastine, palmatine and lesser amounts of canadine and hydrastinine. Preparations derived from Goldenseal have been used to treat skin and eye ailments. Berberine, the major alkaloid in Goldenseal root powder, has been used in eye drops to treat trachoma, a disease characterized by keratoconjunctivitis. Berberine and palmatine are also present in extracts from Berberis amurensis Ruprecht (Berberidaceae) which are used to treat ocular disorders. We have previously shown that Goldenseal alkaloids are phototoxic to keratinocytes (Chem Res Toxicol. 14, 1529, 2001; ibid 19, 739, 2006) and now report their effect on human lens and retinal pigment epithelial cells. Human lens epithelial cells (HLE-B3) were severely damaged when incubated with berberine (25 ,M) and exposed to UVA (5 J cm,2). Under the same conditions, palmatine was less phototoxic and hydrastine, canadine and hydrastinine were inactive. Moderate protection against berberine phototoxicity was afforded by the antioxidants ascorbate (2 mM) and N -acetylcysteine (5 mM). When exposed to UVA (5 J cm,2) both berberine (10 ,M) and palmatine (10 ,M) caused mild DNA damage as determined by the alkaline comet assay which measures single strand breaks. Berberine and palmatine are the only Goldenseal alkaloids with appreciable absorption above 400 nm. Because light at wavelengths below 400 nm is cut off by the anterior portion of the adult human eye only berberine and palmatine were tested for phototoxicity to human retinal pigment epithelial (hRPE) cells. Although berberine did damage hRPE cells when irradiated with visible light (, > 400 nm) approximately 10 times higher concentrations were required to produce the same amount of damage as seen in lens cells. Palmatine was not phototoxic to hRPE cells. Neither berberine nor palmatine photodamaged DNA in hRPE. Infusions of Goldenseal are estimated to contain ,1 mM berberine, while in tinctures the alkaloid concentration may be more than 10 times higher. Our findings show that eyewashes and lotions derived from Goldenseal or containing berberine must be used with caution when the eyes are exposed to bright sunlight but that oral preparations are not likely to cause ocular phototoxicity. [source]


A study of the relationship between the seizure focus and 1H-MRS in temporal lobe epilepsy and frontal lobe epilepsy

PSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 4 2000
Senichiro Kikuchi MD
Abstract Several studies of temporal lobe epilepsy (TLE) patients have investigated the relationship between the seizure focus and 1H magnetic resonance spectroscopy (1H-MRS). There have also been a few reports in other types of partial epilepsy. We examined the relationship between the seizure focus and the reduction in N -acetylaspartate : creatine (NAA : Cr) ratio using 1H-MRS in both TLE and frontal lobe epilepsy (FLE) patients. We studied 21 patients with unilateral TLE and seven patients with unilateral FLE. We used a 1.5 Tesla magnetic resonance unit (Signa Horizon; General Electric). Approximately 15 × 15 × 20 mm3 voxel of interest (VOI) was placed over the anterior portion of the bilateral hippocampus in the TLE patients, and the anterodorsal position of bilateral frontal lobe in the FLE patients. The seizure focus was identified by interictal scalp electro-encephalogram (EEG). In the TLE patients the NAA : Cr ratios were reduced in the seizure focus, while in the FLE patients they were not always reduced in the seizure focus. In the TLE patients the coincidence rate between the seizure focus and the reduction in the NAA : Cr ratio was 90% (19 of 21 patients), while in the FLE patients the coincidence rate was only 57% (four of seven patients). [source]


Ultrastructure of the Spermatozoa of the Yangtze Finless Porpoise (Neophocaena phocaenoides asiaeorientalis)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2009
H. Y. Li
Summary Semen sample was collected from two captive adult Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) during physical examination. One individual was aged about 9 years with body length 143 cm (total length) and body weight 46.1 kg in 2003. The age of the other was unknown and its body length was 147 cm and body weight was 43 kg in 2004. Ultrastructure of their spermatozoa was examined using scanning and transmission electron microscope. The sperm concentration was 4.17 × 109 spermatozoa per ml by the cytometer. The approximate dimensions of the spermatozoa were as follows: head length, 3.366 ± 0.140 ,m (mean ± SE, n = 15); head width, 1.896 ± 0.099 ,m (n = 15); and neck length, 1.004 ± 0.074 ,m (n = 10). The tail included midpiece, principal piece and terminal piece. The length of the midpiece was 1.882 ± 0.077 ,m (n = 9). There is no apparent boundary between the principal piece and the terminal piece, so the length of the principal piece and the terminal piece was 44.612 ± 3.485 ,m (n = 5). Total length of the spermatozoa was 53.314 ± 4.580 ,m (n = 10). The acrosome covered approximately 45.8% of the anterior portion of the head. [source]


Prognostic factors in nonoperative therapy for chronic symptomatic calcific tendinitis of the shoulder

ARTHRITIS & RHEUMATISM, Issue 10 2009
P. Ogon
Objective To define prognostic factors in chronically symptomatic patients with calcific tendinitis of the shoulder. Methods We evaluated 420 patients (488 shoulders) in the context of a prospective cohort study. Epidemiologic data were assessed. The radiographic and sonographic appearance of the calcific deposits was classified. The mean period of nonoperative therapy was 4.4 years (range 0.5,13.7 years). After referral to our institution, standardized nonoperative therapy was continued for a minimum of 3 months. Failure of nonoperative therapy was defined as the persistence of symptomatic calcific tendinitis of the shoulder after a minimum of 6 months. Prognostic factors (determined at P < 0.05 by chi-square test) were analyzed by logistic regression. Results Of the 420 patients, 269 (64%) were women, 151 (36%) were men. The mean age of the patients was 51.3 years (range 28,84 years). Occurrence of calcific tendinitis of the shoulder was unilateral in 84% and bilateral in 16%. Gärtner type I calcific deposits were found in 37%, type II in 32%, and type III in 31%. Failure of nonoperative therapy was observed in 114 patients (27%). Negative prognostic factors were bilateral occurrence of calcific tendinitis of the shoulder, localization to the anterior portion of the acromion, medial (subacromial) extension, and high volume of the calcific deposit. Positive prognostic factors were a Gärtner type III deposit and a lack of sonographic sound extinction of the calcific deposit. Conclusion Our findings demonstrate the existence of prognostic factors in the nonoperative treatment of chronic symptomatic calcific tendinitis of the shoulder. Guidelines for optimal treatment can be implemented according to these factors to avoid a long-term symptomatic disease course. [source]


Paresthesia and hypesthesia in the dorsum of the foot as the presenting complaints of a ganglion cyst of the foot

CLINICAL ANATOMY, Issue 5 2010
Diogo Casal
Abstract Although ganglion cysts of the foot represent a substantial amount of lumps in this region, they rarely cause peripheral nerve symptoms. We describe the clinical case of a 43-year-old female with complaints in the previous three months of hypesthesia and paresthesia in the anterior portion of the medial half of the dorsum of her left foot that extended into the first interdigital cleft. She associated the start of her neurological symptoms to the appearance of a lump in the dorsum of the foot. A presumptive diagnosis of compression of the medial branch of the deep fibular nerve and of the medial dorsal cutaneous nerve in the dorsum of the foot by a ganglion cyst was made. Ultrasonography confirmed the cystic nature of the lesion and surgery allowed complete excision of a mass arising from the joint between the medial and intermediate cuneiform bones that was compressing the deep fibular nerve and the medial dorsal cutaneous nerve. Pathological examination confirmed that the lesion was a cystic ganglion. As far as the authors know, the simultaneous compression of the medial branch of the deep fibular nerve and of the medial dorsal cutaneous nerve in the dorsum of the foot by a ganglion cyst has not been described before. Clin. Anat. 23:606,610, 2010. © 2010 Wiley-Liss, Inc. [source]


Hypothetical anatomical model to describe the aberrant gag reflex observed in a clinical population of orally deprived children

CLINICAL ANATOMY, Issue 7 2006
D.R. Scarborough
Abstract In this ,clinical conundrum', we propose a hypothetical anatomical model to explain the abnormal gag reflex that is consistently observed in a clinical population of children experiencing feeding delays. This model is based on the presence of ,transient' connections formed during the normal development of autonomic brainstem circuitry involving the nucleus tractus solitarius (NTS). We propose that, as a result of normal feeding and swallowing, the activity of these transient fibers typically diminishes shortly after birth. In children who are orally deprived during infancy, these transient connections persist and the aberrant gag reflex is maintained into childhood. The most critical feature of the proposed model is the idea that swallowing during feeding initiates the retraction of the tactile ,transient' input to NTS. In the NICU feeding clinics, it has been suggested that triggering the gag reflex in neonates by tactile stimulation of non-oral body areas and anterior portions of the mouth directly or indirectly may contribute to oral feeding delays. To the contrary, we propose an anatomical model to suggest that oral feeding delays and lack of swallowing food, when experienced by neonates, actually contribute to the development of the aberrant gag reflex observed in later developmental stages. Clin. Anat. 19:640,644, 2006. © 2006 Wiley-Liss, Inc. [source]