Intermediate filaments: dynamic processes regulating their assembly, motility, and interactions with other cytoskeletal systems.
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Animals↗
Biomedical subjects
Y H Chou
Publications and source records attributed to Y H Chou.
Brain uptake and plasma metabolism of [11C]vinpocetine: a preliminary PET study in a cynomolgus monkey.
Vinpocetine, a vinca alkaloid, is a widely used therapeutic agent in patients with acute and chronic stroke. To reveal the mechanisms of vinpocetine action in the brain, vinpocetine was labeled with 11C. Positron emission tomography (PET) was used to determine the uptake and distribution of [11C]vinpocetine in brain regions and the trunk of a cynomolgous monkey in two independent measurements. The concentration of vinpocetine and its labeled metabolites was determined in blood and plasma using high-performance liquid chromatography (HPLC). Almost identical measurements were obtained in the two independent studies. After intravenous administration, following an initial peak, the total concentration of radioactivity in blood was relatively stable with time, whereas the concentration of the unchanged compound decreased with time in an exponential manner. The uptake of [11C]vinpocetine in brain was rapid, and 5% of the radioactivity totally injected was present in the brain 2 minutes after drug administration, indicating that the compound entered the brain readily. The radioactivity uptake was heterogeneously distributed among brain regions and was highest in the thalamus, the basal ganglia, and certain neocortical regions. The high brain uptake and the heterogeneous regional distribution indicate that direct central nervous system (CNS) effects of vinpocetine must be considered as explanation for the therapeutic effects. The detailed exploration of this suggestion requires further studies.
Animals↗
Evaluation of ocular arterial changes in glaucoma with color Doppler ultrasonography.
The purpose of this study was to evaluate hemodynamic changes of the retrobulbar vasculature caused by different intraocular pressures with color Doppler ultrasonography. Fifty normal eyes in 25 patients, 13 patients with normal tension glaucoma, and 19 patients with acute glaucoma and increased intraocular pressure (greater than 30 mm Hg) were enrolled in this study. In 15 of 19 patients with acute glaucoma patients, follow-up color Doppler ultrasonography was also undertaken after laser peripheral iridectomy when the intraocular pressure had returned to normal. The peak systolic velocity, end diastolic velocity, resistive index, time average maximum velocity, and pulsatility index were compared in different vessels, including the central retinal artery, lateral posterior ciliary artery, medial posterior ciliary artery, and ophthalmic artery in each orbit. The peak systolic velocity, end diastolic velocity, and time average maximum velocity of the central retinal artery were significantly lower (P<0.01) in acute glaucoma patients than in the control group. The resistive index and pulsatility index of the central retinal artery were significantly higher (P<0.01) in acute glaucoma patients than in the control group. The end diastolic velocity of the lateral and medial posterior ciliary arteries was significantly lower in patients with acute glaucoma than in the control group, and the resistive index and pulsatility index of both of these arteries were significantly higher (P<0.001) in patients with acute glaucoma than in the control group. However, no statistical significantly differences were found in the peak systolic velocity or time average maximum velocity in either of the posterior ciliary arteries; similarly, no statistically significant differences were noted in any of the parameters in the ophthalmic artery between the control group and the group with acute glaucoma. The pulsatility index of the central retinal artery and of the lateral and medial posterior ciliary arteries was significantly lower (P<0.01) in acute glaucoma patients after laser therapy than in acute glaucoma patients before laser therapy. The resistive index of both posterior ciliary arteries was also significantly lower (P<0.004) in acute glaucoma patients after laser therapy than before laser therapy. All parameters for all vessels examined among the normal subjects, the patients with normal tension glaucoma, and the patients with acute glaucoma after laser therapy when the intraocular pressure had returned to normal showed no statistically significant differences. Color Doppler ultrasonography is a good modality for both imaging and studying the hemodynamics of the perioptic nerve vessels.
Aged↗
Alternative and effective treatment of shoulder ganglion cyst: ultrasonographically guided aspiration.
The therapeutic effect of ultrasonographically guided aspiration of a ganglion cyst of the shoulder is evaluated. Fifteen patients (nine male, six female) with chronic shoulder pain were enrolled in this study. Each patient was referred to rule out rotator cuff lesion. The ultrasonographic examination showed an anechoic cystic lesion in the shoulder region in every patient and abnormality of the rotator cuff in only four patients. Under ultrasonographic guidance, an 18 gauge needle was inserted into the cyst to aspirate the fluid. Initial sonographic imaging showed the cyst, which appeared as a localized fluid accumulation and was located between the deltoid muscle and the subscapularis tendon in seven patients, between the deltoid muscle and the biceps tendon in one patient, below the coracoacromial ligament in five patients, and over suprascapular notch area in one patient. The ganglion cysts ranged in size from 3.5 to 30 mm. The amount of aspirated fluid in each cyst varied from 0.4 to 12 ml (mean, 2.6 ml +/- 3.1) with a clear or light yellowish color and a jelly-like appearance. No major complications occurred during or after this procedure. The symptom (pain) was improved after sonographically guided aspiration in each patient. Follow-up study showed complete relief of pain in four patients, marked improvement in nine patients, and mild improvement but still persistent shoulder pain in two patients. Duration of follow-up study ranged from 2 to 24 months (mean, 6.4 months +/- 6.9). The success rate for sonographically guided aspiration was 86% on the basis of marked symptom improvement or relief. Ultrasonographically guided aspiration of shoulder ganglion cysts is an effective procedure in the management of shoulder pain caused by ganglion cysts.
Adult↗
[Torsion of the appendix testis].
The differential diagnosis of an acute scrotum includes spermatic cord torsion, torsion of a testicular appendage, torsion of spermatocele, epididymitis, orchitis, trauma, hernia, testicular segmental infraction and tumor. Among these, torsion of appendix testis could got dramatic improvement if accurately diagnosed and treated. 5 patients of torsion of appendix testis have been identified in our hospital in the recent 5 years. Ages ranged from 9 to 13 years old (mean age 11). The lesions were on the right side in 2 cases and left side in 3 cases. Duration of scrotal pain ranged from 2 to 7 days (mean of 4 days). The urine analyses were normal in all cases. The white blood counts were all within normal limits with mean of 5.72 x 10(3)/ul. No abnormality in passing urine or other infectious sign could be detected. Doppler ultrasonography or nuclear medicine testicular scan were performed selectively due to clinical availability. The result was equivocal and did not support a definite diagnosis. All 5 cases received surgical treatment. The necrotic testicular appendix was excised and reactive hydrocele treated. All the patients were discharged from the hospital the day after operation and recovered quickly. The pathological report revealed congestion and extensive hemorrhagic necrosis of the testicular appendix. Advances in technology have been helpful in improving the accuracy of diagnosis but technology is not infallible and an over reliance on it can also result in misdiagnosis. Various reports supporting the use of scrotal ultrasound in evaluating cases of acute scrotum pain. Ultrasonography has definitely helped in detecting scrotal pathology but its limitations need to be appreciated. Because of the difficulty of making an accurate diagnosis in acute scrotum, misdiagnosis and delayed operation offer result in disappointment of testis salvage rates. We have supported a policy of early scrotal exploration in any case suspicious of torsion of appendix testis.
Child↗
Technological progress in ultrasonography.
Technical progress in ultrasonography (US) is especially rapid now, due to continuing advances in transducer design, signal processing techniques, and Doppler technology. A number of important technical breakthroughs have been made in the past decade. Among these, multidimensional array transducers, harmonic imaging, miniaturized transducers, extended field-of-view imaging, hand-carried ultrasound units, three-dimensional (3-D) US, and ultrasound contrast agents are the most remarkable innovations. Improved spatial and contrast resolution allows delineation of anatomic details and increases diagnostic accuracy and confidence. Miniaturized transducers can be used to image tiny or superficial structures in the human body, and can guide the surgeon to the problem site. Extended field-of-view imaging provides a larger field for demonstration of pathology in certain anatomic locations. Hand-carried US units are used widely in a physician's office or in remote areas, and bring high-quality medical imaging to the bedside. 3-D US has already shown significant benefits in perinatology; with further improvements in real-time imaging technology, 3-D US will emerge as an important adjunct to conventional 2-D US. In conjunction with harmonic imaging technology and Doppler technology, US contrast agents allow more powerful anatomic and functional evaluation of human organs. They may also play important therapeutic roles in the near future. Advancing computer technology is expected to lead to more important break-throughs in the next 5 to 10 years.
Humans↗
K-ras codon 12 mutation determines the polypoid growth of colorectral cancer.
Colorectal carcinogenesis is widely thought to follow the adenoma-adenocarcinoma sequence. However, there are two morphologically distinct subtypes of colorectal cancer (CRC), polypoid and ulcerative. We conducted a comparative study to clarify whether different combinations of some commonly involved genetic alterations (including mutations in K-ras, p53, DCC, APC, and Rb genes) may exist between polypoid- and ulcerative-type CRCs, the two morphologically distinct types of CRC. By using PCR-based RFLP, single-strand conformational polymorphism, and loss of heterozygosity analysis, we found that K-ras codon 12 mutation was preferentially involved in polypoid tumor (P < 0.0001). There were no other significant correlations with p53 point mutation or loss of heterozygosity in chromosomes 5q, 17p, and 18q and Rb gene, which have been suggested to be involved in the progression of CRC of both morphological types. Therefore, different combinations of molecular genetic alterations may be involved in morphologically distinct types of colorectal carcinogenesis, and the K-ras codon 12 mutations may play an important role in polypoid growth of CRC. These results shed light on the function of K-ras oncogenes involved in colorectal carcinogenesis and may be important in the future design of genetic screening programs, determination of prognosis, and treatment for patients with CRC.
Codon↗
Differential effects of phorbol ester on growth and protein kinase C isoenzyme regulation in human hepatoma Hep3B cells.
PMA has both mitogenic and antiproliferative effects on human hepatoma Hep3B cells. In response to low PMA concentration (10 nM), Hep3B cells displayed an increasing proliferation potentiation. At high PMA concentration (1 microM) Hep3B cells exhibited modest cytostatic effects. Determinations of protein kinase C (PKC) activity in PMA-treated cells revealed that alterations in PKC activity are associated with proliferative capacity. The decrease in PKC activity mediated by a high dose of PMA was accompanied by cell growth inhibition. Increases in PKC activity mediated by a low dose of PMA were consistent with proliferation stimulation. Immunoblot analysis showed that there are at least six PKC isoenzymes: alpha, delta, epsilon, mu, zeta and iota/lambda, constitutively expressed in Hep3B cells. Cellular fractionation and immunocytochemical staining results demonstrated that both 10 nM and 1 microM PMA treatments induced a marked translocation of PKC-alpha from cytosol to membrane or nuclear fraction within 5-30 min. At the same time PKC-delta and epsilon were translocated from the membrane to nuclear fraction. In addition, prolonged treatment with 1 microM PMA, but not with 10 nM PMA, selectively mediated the down-regulation of these three PKC isoenzymes. The distinct effects of different concentrations of PMA on cell proliferation and PKC-alpha, delta and epsilon isoenzyme modulation support the involvement of these three PKC isotypes in the mechanism of action of Hep3B cells in cell growth events.
Antineoplastic Agents↗
Frequent allelic loss on chromosomes 4q and 16q associated with human hepatocellular carcinoma in Taiwan.
To define the critical region of liver-specific tumor suppressor genes in human hepatocellular carcinoma (HCC), we analyzed 30 cases of hepatocellular carcinoma using nine 4q and six 16q microsatellite polymorphic DNA markers. We observed one major common deleted region which was flanked by D4S175-D4S1625 and there may be two tumor suppressor genes on chromosome 16q associated with HCC. An extensive study of allelotyping of human HCC was therefore carried out in the candidate region on arms of chromosome 4q with additional tumor tissues and more informative microsatellite DNA markers. These data imply that at least one putative tumor suppressor gene is located in the human chromosome 4q26-q27 region and provides very useful information for further construction of a long-range physical restriction map and thereafter cloning of the putative tumor suppressor gene.
Carcinoma, Hepatocellular↗
Primary cardiac leiomyosarcoma: imaging with 2-D echocardiography, electron beam CT and 1.5-Tesla MR.
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Adult↗
Ultrasound-guided interventional procedures in splenic abscesses.
The results of ultrasound (US)-guided interventional procedures over a period of 12 years in 21 consecutive patients with splenic abscess were reviewed. The interventional procedures were done with 21- or 18-gauge needles for aspiration of relatively small abscesses (< 3.5 cm) in eight patients and with an 8.3-9.0 French pigtail catheter for continuous drainage in 13 patients with larger abscesses (> or = 3.5 cm). In some patients, multiple abscesses were treated separately according to their various sizes. More than one catheterization were done in three patients because of detached catheter or recurrent abscesses. The interventional procedures were followed by at least eight weeks of appropriate antibiotic therapy. Only one patient had the complication of minimal subcapsular hematoma which needed no further treatment. All the patients had uneventful clinical courses. US-guided interventional procedure proved to be a treatment-of-choice for splenic abscess, and may avoid splenectomy by conserving the spleen.
Abscess↗
Clinical application of the measurement of cord plasma lactate and pyruvate in the assessment of high-risk neonates.
Lactate levels in combination with lactate/pyruvate (L/P) ratio have been used to measure altered cellular redox states. We measured the cord plasma lactate levels and L/P ratios in 70 normal neonates (40 full-term and 30 preterm neonates) to set up the normal (control) ranges. The control cord plasma lactate levels and L/P ratios were 2660 [700 (SD)] micromol/l, 16 (3) in full-term neonates and 2750 (740) micromol/l, 17 (3) in preterm neonates, respectively. We also measured the lactate levels and L/P ratios in the high-risk full-term (n = 23) and preterm (n = 35) neonates, the results were 4500 (2600) micromol/l, 19 (13), and 5100 (2700) micromol/l, 26 (12), respectively. With the aid of elevated lactate levels and L/P ratios, the occurrence of neonatal encephalopathy can be predicted with a sensitivity of 100% and a specificity of 94.5% in this patient group. In our study, the six cases with abnormal neurodevelopment at 6-9 months of age all had both elevated lactate levels and L/P ratios at birth. We conclude that the measurement of lactate levels in combination with L/P ratios is a useful quantitative tool in assessing the existence and severity of perinatal hypoxia in the high-risk neonates.
Female↗
Association of fungal colonization and invasive disease in very low birth weight infants.
BACKGROUND: Fungi are common pathogens of nosocomial infections in the very low birth weight (VLBW) infants. The purpose of this study was to investigate the fungal colonization rate in VLBW infants and the association between fungal colonization and systemic fungal diseases. MATERIALS: Between January 1, 1996, and December 31, 1996, 116 infants with birth weight < 1500 g admitted to the neonatal intensive care unit of Chang Gung Children's Hospital in the first day of life were included in this prospective study. METHODS: Cultures from oropharynx, rectum, skin (groin and axilla), bag urine and endotracheal aspirates were obtained in the first 24 h after birth and weekly thereafter throughout their neonatal intensive care unit stay. Medical records were reviewed weekly. RESULTS: Fungal colonization was detected in 25 infants, among whom 17 infants developed colonization by 2 weeks of life. Candida albicans (61%) and Candida parapsilosis (29%) were the 2 most common organisms. The rectum (76%) was the most frequent site of colonization. Factors significantly associated with colonization were prolonged administration of antibiotic therapy, parenteral nutrition and intralipid emulsion. Three of 116 infants developed fungemia. The association between colonization and subsequent fungemia was demonstrated in 1 infant, representing 4% of colonized infants. CONCLUSION: Fungal colonization was detected in one-fifth of VLBW infants and represents a risk factor for fungemia. Because disease occurred in the absence of apparent colonization, factors other than colonization may contribute to invasive candidiasis.
Candida↗
Triangular fibrocartilage of wrist: presentation on high resolution ultrasonography.
This study consisted of two parts. Part I is for detection of the normal triangular fibrocartilage by high resolution ultrasonography and Part II is a preliminary study to evaluate high resolution ultrasonography in the diagnosis of tears of the triangular fibrocartilage. Normally, the triangular fibrocartilage was seen in all cases in Part I as an inverse triangular structure of homogeneous hyperechogenicity on transverse and oblique sagittal scans at the level of the distal radioulnar joint. At its waist it measured from 2.3 to 4.2 mm (mean, 3.0 +/- 0.5 mm) on oblique sagittal scan and from 2.5 to 3.7 mm (mean, 3.2 +/- 0.4 mm) on transverse scan. Under normal conditions, the triangular fibrocartilage is thicker than 2.5 mm on both transverse and oblique sagittal sections with a confidence level of 95%. In Part II, eight of the 47 wrists were found to be hypoechoic in the triangular fibrocartilage region, which proved to be tears by arthrography. Six cases showed a homogeneous hyperchoic triangular fibrocartilage measuring from 1.8 to 2.8 mm (mean, 2.3 +/- 0.5 mm) in transverse section and from 0 to 2.2 mm (mean 1.2 +/- 1.1 mm) in oblique sagittal section; five of these proved to be tears by arthrography. In contrast, 33 wrists had a homogeneous hyperechoic triangular fibrocartilage measuring from 2.5 to 4 mm (mean, 3.1 +/- 0.4 mm) and 2.5 to 4.2 mm (mean, 3.1 +/- 0.6 mm) on transverse and oblique sagittal sections, respectively; 27 proved to be normal triangular fibrocartilage by arthrography. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 68.4%, 96.4%, 92.9%, 81.8%, and 85.1%, respectively. HRUS can display the normal triangular fibrocartilage as a homogeneous hyperechoic and inverted triangular structure. The torn triangular fibrocartilage appears as a hypoechoic region or as thinning (< 2.5 mm) of the hyperechoic structure on either transverse or oblique sagittal section. HRUS has an acceptable accuracy in the diagnosis of triangular fibrocartilage tear.
Adolescent↗
Cubital tunnel syndrome: diagnosis by high-resolution ultrasonography.
The purpose of this study was to evaluate the morphologic changes in the ulnar nerve in cubital tunnel syndrome with high-resolution ultrasonography. The mean values of the short axis (cm) x long axis (cm) at the arm, epicondyle, and forearm levels were 0.057 +/- 0.01, 0.068 +/- 0.019, and 0.062 +/- 0.01 in control group; 0.069 +/- 0.04, 0.139 +/- 0.06, and 0.066 +/- 0.023 in the symptomatic side in patients with cubital tunnel syndrome; and 0.063 +/- 0.029, 0.068 +/- 0.029, and 0.057 +/- 0.012 in the normal side in patients with cubital tunnel syndrome. No significant difference was found in the area (short axis x long axis) of the ulnar nerve at the arm, epicondyle and forearm levels between the left and right ulnar nerve in the control group and between the control group and the normal side in symptomatic patients. However, the mean value of the area of the ulnar nerve at the epicondyle level in symptomatic patients was significantly larger than that of the control group and that of the contralateral side in patients, and the P value was less than 0.001. High resolution ultrasonography can detect morphologic changes in the ulnar nerve accurately, and it could therefore be useful as a screening and even follow-up modality in patients with cubital tunnel syndrome.
Adult↗
Verifying complete obliteration of carotid artery-cavernous sinus fistula: role of color Doppler ultrasonography.
The purpose of this study was to evaluate the role of color Doppler ultrasonography in verifying obliteration of carotid artery-cavernous sinus fistula before and after therapeutic embolization or gamma knife radiosurgery. Before treatment, carotid artery-cavernous sinus fistula showed the following data on color Doppler ultrasonography: (1) increased blood flow in the common carotid artery (220 to 1264 ml/min with mean+/-SD of 728+/-378 ml/min); internal carotid artery (435 to 1097 ml/min with mean+/-SD of 834+/-216 ml/min) in fistulas of the direct type; and external carotid artery (85 to 257 ml/min with mean+/-SD of 170+/-75 ml/min) in fistulas of the indirect type in comparison to the contralateral side; (2) reverse pulsatile flow or spiculated wave form with turbulent flow in the engorged superior ophthalmic vein on the lesion side in all patients. All of the above abnormal hemodynamic changes became normal in six patients immediately after first embolization, in two patients with balloon embolization combined with subsequent direct embolization by direct puncture through the superior orbital fissure or internal carotid artery embolization, and in five patients after gamma knife radiosurgery at 4, 4, 8, 9, and 9 months, respectively. Color Doppler ultrasonography might be a good modality in long-term follow-up of carotid artery-cavernous sinus fistula after gamma knife radiosurgery and embolization.
Adolescent↗
The use of prophylactic intravenous immunoglobulin therapy in very low birthweight infants.
BACKGROUND: Nosocomial infections are a major cause of death in premature infants, especially in very low birthweight (VLBW) infants. The VLBW infants have low serum immunoglobulin G levels, which may have an effect on infections in early infancy. Thus, prophylactic administration of intravenous immunoglobulin (IVIG) is proposed to maintain higher immunoglobulin G and reduce the rate of hospital-acquired infection. MATERIALS AND METHODS: A study for the effects of prophylactic IVIG therapy in VLBW infants was performed. A total of 61 VLBW infants were enrolled, and divided into the IVIG group (n = 31) and the control group (n = 30). The dose for each infant was 750-1000 mg/kg for those whose birthweight was less than 1000 g, and 500-750 mg/kg for infants whose birthweight was between 1001 and 1500 g. The control group received saline infusion. The infusions were given every 2 weeks until the infant weighed 1800 g, or was discharged. RESULTS: The results showed: there were no major differences in the perinatal and neonatal characteristics between the two groups, consistently higher IgG levels were found in the IVIG group, and the age of first documented sepsis was earlier in the control group. CONCLUSION: In this study, the prophylactic IVIG therapy may give substantially higher IgG levels, which may last for 2 months. However, a prophylactic effect for hospital-acquired infections was not observed.
Cross Infection↗
Successful resection of sigmoid colon cancer in a patient with factor XI deficiency.
A 42-year-old-women with sigmoid colon adenocarcinoma was found to have isolated prolonged activated partial thromboplastin time (aPTT 102.5 s, normal range 24-36 s) preoperatively. Her medical history included an episode of prolonged postdelivery uterine bleeding 16 years previously. A mixed aPTT test showed immediate correction of the prolonged aPTT, indicating a coagulation factor deficiency in the intrinsic pathway. Factor assays showed factor XI was below 1% of average normal value whereas factor VIII, IX and XII activities were normal. Family screening revealed one sister among the three siblings also had isolated prolonged aPTT. The patient was transfused with four units (5mL/kg) of fresh frozen plasma the day before surgery, then with two units during surgery. The operation was uneventful with no bleeding problems. The patient recovered smoothly and is currently undergoing adjuvant chemotherapy. This is the first formal report of a patient with factor XI deficiency undergoing major surgery in Taiwan. Careful monitoring of aPTT, with fresh frozen plasma transfusion, when needed, may safely overcome bleeding problems during surgery.
Adenocarcinoma↗