Biomedical subjects

C M Wu

Publications and source records attributed to C M Wu.

At least 19 recordsLinked to original sources

PubMed2001

A novel platelet-rich arterial thrombosis model in rabbits. Simple, reproducible, and dynamic real-time measurement by using double-opposing inverted-sutures model.

Though numerous animal thrombosis models have been introduced, an easy, reliable, and reproducible arterial thrombosis model remains a continuing challenge prior to a thrombolytic study. In an effort to evaluate the efficiency of various recombinant thrombolytic agents with specific affinity to activated platelets in vivo, we developed a novel double-opposing inverted-sutures model to create a platelet-rich thrombus in the femoral artery of rabbits. The arteriotomy was done semicircumferentially, and variously sized microsurgical sutures were introduced intraluminally in a double-opposing inverted manner. The animals were divided into three groups according to the double-opposing inverted-sutures used: Group 1 with 10-0 nylon (n=6), Group 2 with 9-0 nylon (n=6), and Group 3 with 8-0 nylon (n=22). The superficial epigastric branch was cannulated with a thin polyethylene (PE) tube for intraarterial administration of the studied thrombolytic agent. The blood flow was continuously measured with a real-time ultrasonic flow meter. Within 2 h of installation of the sutures, there was no thrombus formation in either Group 1 or 2. In Group 3, the thrombosis rate was 91% (20 of 22) under a steady baseline flow (with an average of 12.23+/-2.40 ml/min). It was highly statistically significant with a P-value of .0000743 using Fisher's Exact Test. The averaged time to thrombosis was 21.8+/-9.8 min. The ultrasonic flow meter to record the dynamic real-time measurement of blood flow was a guideline for thrombus formation or dissolution, which was correlated with the morphological findings of stenotic status of the vessel detected by the Doppler sonography. The components of the thrombus were proven to be platelet-rich predominant by histological examination via hematoxylin and eosin (H&E) stain and transmission electron microscopy (TEM). To confirm that the double-opposing inverted-sutures model would be useful for a study of thrombolytic agents, we evaluated the effects of recombinant tissue-type plasminogen activator (rt-PA) and streptokinase-human plasminogen (SK-HPlg). The average time to thrombolysis post rt-PA infusion was 16.0+/-8.2 min and that of SK-HPlg was 79.6+/-23.1, which were similar to the previous reports. In conclusion, the novel double-opposing inverted-sutures (8-0 nylon) model provides a simple, reliable, and reproducible platelet-rich arterial thrombosis model with noninvasive and dynamic real-time measurement. It may be applied in assessing the efficiency of the recombinant thrombolytic agents and offers many advantages of an arterial platelet-rich in vivo thrombosis model.

Animals↗

PubMed2001

Computerized medical records in the Department of Veterans Affairs.

The VA Medical Center in Washington, DC, was the nexus for a number of computerization projects that were initiated by the Department of Veterans Affairs. The culmination of these initiatives is a software package that presents the complete electronic patient record in an easy-to-use graphic user interface. This record combines text data from the legacy data base, diagnostic images from patient procedures, electrocardiograms from a commercial server, an Internet connection, and a hospital web site with pertinent reference information. The information is available in over 1000 places in the hospital and can be accessed remotely using a remote access server. The computerization of the medical record has improved hospital efficiency, has made physician access to patient information more reliable, has opened new opportunities for patient education, and has given healthcare providers more time to care for patients.

Diagnostic Imaging↗

PubMed2001

Tumour necrosis factor-alpha causes an increase in blood-brain barrier permeability during sepsis.

Blood-brain barrier (BBB) permeability during sepsis with Escherichia coli or Streptococcus pneumoniae was examined in a mouse model and measured by a circulating beta-galactosidase tracer. The leakage of brain microvascular vessels during sepsis was confirmed by transmission electron microscopic examination of brain tissues stained with horseradish peroxidase. The increase of BBB permeability induced by E. coli and S. pneumoniae, which was maximal at 3 h and 12 h after injection, respectively, was transient because of rapid clearance of the bacteria from the blood. Tumour necrosis factor-alpha (TNF-alpha) was stained on microvascular vessels of the brain during sepsis and intravenous injection of recombinant TNF-alpha also increased the BBB permeability. The increase in BBB permeability induced by either E. coli or S. pneumoniae could be inhibited by anti-TNF-alpha antibody. It was concluded that circulating TNF-alpha generated during sepsis induced the increase in BBB permeability.

Animals↗

PubMed2001

Human progesterone receptor shows differential sensitivity to carboxyl group modifying agents when bound to agonist and antagonist ligands.

BACKGROUND: Modulation of human uterine progesterone receptor (PR) in relation to its binding to synthetic steroids with known agonist (R5020) and antagonist (triamcinolone acetonide, T.A.) properties was studied in the presence of the specific carboxyl group modifiers, N,N'-dicyclohexylcarbodiimide (DCCD) and 1-ethyl-3-carbodiimide hydrochloride (EDC). METHODS: Uterine cytosol was treated with DCCD or EDC. The amounts of total bound were detected using the steroid binding measurements. The formation and transformation of progesterone-receptor complexes (PRc) were analyzed using sedimentation rate analysis. RESULTS: Our studies show that the modification of the COOH group differentially influences the properties of mammalian PR binding with either R5020 or T.A. DCCD and EDC affect the steroid binding of PR by decreasing the binding sites, not by the changing the affinity. CONCLUSION: Our studies indicate the importance of the carboxyl group in steroid binding by PR. This implies that both aspartic acid and glutamic acid residues, which have the carboxyl group, may play an important role when PR binds with steroid ligands.

Cytosol↗

PubMed2001

[Multiple focal cortical dysplasias presenting with intractable epilepsy: case report].

A 14-year-old female, who had intractable epilepsy associated with multiple focal cortical dysplasias (FCD), was reported. She developed intractable epilepsy at the age of 7 and was diagnosed as having frontal lobe epilepsy based on the seizure semiology and interictal EEG. MRI revealed multiple lesions in the right frontal, bilateral occipital and left parietal lobes. EEG demonstrated that ictal discharge was preceded by spike on the right frontal region and FDG-PET showed hypometabolic area in the right frontal lobe. Chronic subdural electrode recordings from the right frontal lobe indicated that ictal onset zone was located around the right frontal lesion, especially frontal tip and base, and these areas including the lesion were resected. Postoperatively, residual seizure was noted although seizure frequency was decreased. It is well known that, postoperatively, satisfactory seizure outcome can be obtained in patients with FCD. However, further investigation in terms of surgical indication and strategies for multiple FCD should be needed.

Adolescent↗

PubMed2000

Volatile compounds produced from monosodium glutamate in common food cooking.

A mixture of soybean oil and/or water, sugar and/or monosodium glutamate (MSG) was water-boiled or oil-heated at 100, 120, 140, 160, or 170 degrees C, respectively, and volatile compounds produced were isolated by solid-phase microextraction and then identified by GC and GC/MS. Oxidative thermal degradation products of fatty acids (OTDPFA) were the major volatile compounds detected for all water-boiled samples. When MSG and sugar were heated together, 2, 5-dimethyl pyrazine and methyl pyrazine were also detected at or after 160 min heating. Water added in soybean oil increased OTDPFA production. In oil-heated samples of soybean oil alone, soybean oil with MSG, and soybean oil with sugar, OTDPFA were also the major compounds found. The samples containing MSG also produced 2-pyrrolidone, and the samples containing sugar also produced furfural and 5-hydroxy methyl furfural. The samples containing soybean oil, sugar, and MSG produced 23 pyrazines, OTDPFA, and gamma-butyrolactone as the major volatile compounds. The contents of OTDPFA were lower in MSG plus sugar and MSG-added samples, and it is postulated that antioxidant activities were produced in cooking.

Chromatography, Gas↗

PubMed1999

Optimal control of blood pressure can reverse left ventricular hypertrophy in uremic hypertensive hemodialysis patients.

We investigated the effects of antihypertensive treatment on left ventricular hypertrophy (LVH) of long-term hemodialysis patients. In uremic patients, it is still controversial in antihypertensive effect to the regression of LVH. The left ventricular size and function of 39 uremic hypertensive long-term hemodialysis patients (27 men, 12 women, mean age 58.3) was evaluated with M-mode, 2-dimensional and Doppler echocardiography before, and 12 months after, the start of combined antihypertensive therapy. This therapy included angiotensin II converting enzyme inhibitors, beta-blockers and calcium antagonists. Patients were classified as responders or nonresponders, depending upon whether their systolic blood pressure (SBP) decreased by more than 10 mmHg after antihypertensive treatment for 12 months. Before treatment, 36 (92%) patients had LVH and diastolic dysfunction and three (8%) had systolic dysfunction. At the end of 12 months, only 25 (64%) patients had LVH, 30 (77%) had diastolic dysfunction and 2 (5%) had systolic dysfunction. Left ventricular mass index (LVMI) also decreased from 203.63 +/- 70.47 g/m2 to 178.57 +/- 67.31 g/m2. LVMI correlated with systolic blood pressure (SBP) but did not correlate with diastolic blood pressure (DBP). There were 26 responders and 13 non-responders. Among responders, both the SBP (153.91 +/- 13.24 mmHg vs 134.43 +/- 14.21 mmHg, p < 0.01) and DBP (90.39 +/- 7.89 mmHg vs 79.98 +/- 7.35 mmHg, p < 0.01) decreased significantly after antihypertensive therapy. Responders also exhibited progressive regression of LVH (LVMI decreased significantly from 208.52 +/- 72.03 g/m2 to 168.52 +/- 55.53 g/m2, p < 0.05). However, LVH regression was not found in nonresponders (LVMI showed 194.84 +/- 64.36 g/m2 vs 193.66 +/- 77.67 g/m2). We conclude that good control of blood pressure can reverse LVH in hypertensive hemodialysis patients.

Adult↗

PubMed1999

[Utilizing the PRECEDE model to predict health examination behavior of the elderly].

Health examination of the elderly in Taiwan, the reported rates of health examination of the elderly were always below 30%. In order to explore the predictors related to the behavior of health examination of the elderly, the PRECEDE model was adopted for this study. Both the 1200 participants and spare samples were recruited from eleven districts of Kaohsiung city. 1193 participants had been completed by home interview. Sample size was based on the distribution of the elderly in the whole city and the stratified sampling method was applied. There was no significant difference after comparing the rates of gender, age, and examination between sample and population. The results showed that seven factors could be used to predict the behavior of health examination of the elderly. In the individual predisposing factors, "numbers of chronic diseases", "knowledge of health examination", "previous health examination", and "health promotion behavior" were related to the behavior of health examination of the elderly. In reinforcing factors, "attitude of family members for health examination", and in enabling factors "the guide and the convenience of health-examined services" also showed significantly affecting examination behavior. Therefore, referring to the improvement to be the examination rate, we can intervene or do something through academic, practical and administrative approaches.

Aged↗

PubMed1998

Radiologic evaluation of the acute abdomen in the patient with acquired immunodeficiency syndrome (AIDS): the role of CT scanning.

Abdominal complaints are common in the HIV-infected patient, and the signs and symptoms of disease may be masked by concurrent illness and a weak immune response, making accurate diagnosis difficult. Patients with acquired immunodeficiency syndrome (AIDS) are susceptible to diseases common to the general population; however, their generalized state of immunodeficiency places them at increased risk for many unusual disorders, predominately infectious and neoplastic. Radiologic evaluation, in particular, computed tomography (CT) with its ability to image the entire abdomen and pelvis, plays a crucial role in the prompt and accurate diagnosis and treatment of these patients.

AIDS-Related Opportunistic Infections↗

PubMed1998

Musculoskeletal complications of the patient with acquired immunodeficiency syndrome (AIDS): CT evaluation.

Musculoskeletal disorders are infrequent complications of HIV infection in this country. However, AIDS patients are susceptible to a wide range of musculoskeletal complications, from the common to the otherwise uncommon. The following is a summary of some of the more frequently encountered musculoskeletal manifestations of these disorders within the HIV-positive community and their associated imaging characteristics.

Acquired Immunodeficiency Syndrome↗

PubMed1997

A subpopulation of reactive astrocytes at the immediate site of cerebral cortical injury.

We have identified an early-appearing intermediate filament-associated protein (IFAP-70/280 kDa) in radial glia and their immediate derivatives. This IFAP is absent in the adult CNS. In this study, we examined the reexpression of this early glial differentiation trait in rat reactive astrocytes induced by stab injury of the cerebrum. Double-label immunofluorescence microscopy demonstrated that by 36 h postlesion, IFAP-70/280 kDa was present in a few GFAP-positive astrocytes in the area adjacent to the wound. As the gliotic reaction progressed, the number of IFAP-positive reactive astrocytes increased and by 5-6 days postlesion, IFAP-70/280 kDa was present in most of the hypertrophied astrocytes in tissue immediately adjacent to the wound. By 8 days postlesion, while the number of IFAP-negative reactive astrocytes away from the wound diminished, the IFAP-containing reactive astrocytes close to the wound persisted. Concurrently, they began to change from a stellate form to an elongated shape, with their longitudinal axes radiating from the wound. The immunoreactivity of this IFAP started to diminish at 20 days postlesion, and by 30 days postlesion, it was not observed in the remaining gliotic cells. These results demonstrate that reactive astrocytes induced by stab-wound injury can be divided into two subtypes: persistent IFAP-70/280 kDa-containing cells which are close to the wound in the area of the glial scar and transient IFAP-70/280 kDa-negative cells which are farther from the wound. The reappearance of IFAP-70/280 kDa also suggests that some reactive astrocytes have the capacity to recapitulate early developmental stages.

Animals↗

PubMed1997

Corticotropin-releasing hormone stimulates the expression of the steroidogenic acute regulatory protein in MA-10 mouse cells.

We have previously demonstrated that corticotropin-releasing hormone (CRH) treatment of MA-10 mouse Leydig tumor cells results in a dose-dependent stimulation of progesterone production. In view of this observation we wished to determine the effects of CRH on the synthesis of the steroidogenic acute regulatory (StAR) protein in these cells. StAR is a steroidogenic tissue-specific, hormone-induced, rapidly synthesized protein previously shown to be involved in the acute regulation of steroidogenesis, probably by promoting the transfer of cholesterol to the inner mitochondrial membrane and the cytochrome P450 side-chain cleavage enzyme. Treatment of MA-10 cells with the cAMP analogue dibutyryl cAMP (dbcAMP) resulted in a dose- and time-dependent increase in the levels of StAR protein that reached a maximum at 800 microM dbcAMP and within a time period of 6 h. Further, treatment of MA-10 cells with CRH also resulted in a dose-dependent increase in the synthesis of the StAR protein with a maximal response observed at 1 microM. Slightly different from that observed with dbcAMP, the maximal response to 1 microM CRH was seen at 4 h following stimulation. These results indicate that the observed increase in steroid production in response to CRH in MA-10 Leydig tumor cells is similar to that previously seen with trophic hormone stimulation acting through the cAMP second messenger pathway, and that it occurs as a result of an increase in the synthesis of the StAR protein.

Animals↗

PubMed1997

A technique for extracting physiological parameters and the required input function simultaneously from PET image measurements: theory and simulation study.

Positron emission tomography (PET) is an important tool for enabling quantification of human brain function. However, quantitative studies using tracer kinetic modeling require the measurement of the tracer time-activity curve in plasma (PTAC) as the model input function. It is widely believed that the insertion of arterial lines and the subsequent collection and processing of the biomedical signal sampled from the arterial blood are not compatible with the practice of clinical PET, as it is invasive and exposes personnel to the risks associated with the handling of patient blood and radiation dose. Therefore, it is of interest to develop practical noninvasive measurement techniques for tracer kinetic modeling with PET. In this paper, a technique is proposed to extract the input function together with the physiological parameters from the brain dynamic images alone. The identifiability of this method is tested rigorously by using Monte Carlo simulation. The results show that the proposed method is able to quantify all the required parameters by using the information obtained from two or more regions of interest (ROI's) with very different dynamics in the PET dynamic images. There is no significant improvement in parameter estimation for the local cerebral metabolic rate of glucose (LCMRGlc) if the number of ROI's are more than three. The proposed method can provide very reliable estimation of LCMRGlc, which is our primary interest in this study.

Brain↗

PubMed1997

A substance isolated from Cornus officinalis enhances the motility of human sperm.

The effects of a Chinese herb, Cornus officinalis, on the motility of human sperm was studied. An aqueous extract was prepared from the dried fruits of the herb and used in this study. The crude extract at a final concentration of 0.5 microgram/microliter in phosphate buffered saline (pH 7.4) increased sperm motility from 25.8 +/- 7.7% to 42.8 +/- 10.3% (i.e. 68% increase, n = 7), as determined by the computer-aided-sperm-analysis (CASA) method. The crude extract was fractionated by high-performance liquid chromatography (HPLC) into four fractions: C1, C2, C3 and C4. Their effects on sperm motility were further studied by CASA. Only the C4 fraction showed substantial stimulatory effects on sperm motility. At a concentration of 5 ng/microliter, C4 increased the sperm motility from 15.7 +/- 3.8% to 34.5 +/- 6.4% (i.e. 120% increase, n = 6) by CASA and from 14.9 +/- 4.3 to 28.5 +/- 8.1 (i.e. 91% increase, n = 8) by transmembrane migration ratio (TMMR) method. This result suggests that C4 is the active component in Cornus officinalis that enhances sperm motility.

Chromatography, High Pressure Liquid↗

PubMed1997

Transthoracic endoscopic sympathectomy for treatment of hyperhidrosis palmaris.

The objective of this study was to determine the effectiveness of modified transthoracic endoscopic sympathectomy (TES) being used in our institute for treatment of hyperhidrosis palmaris (HP). One hundred and eight cases of HP were treated using TES from June 1991 to June 1992. All underwent TES bilaterally. Palmar temperature was monitored during the operation as an indicator of a successful lesioning of the sympathetic trunk at the T2-level. The ages of the patients ranged from 10 to 61 years. Fifty-one percent of these patients had a positive family history. Seventy-three percent had onset during childhood. Eighty-nine percent had excessive plantar sweating in addition to hyperhidrosis palmaris. The increase in palmar temperature after lesioning the sympathetic trunk was inversely related to the preoperative temperature of the palms (r = 0.81, p < 0.005). Our treatment resulted in improvement of palmar sweating in all of the patients. Decrease of plantar sweating was also noted in 68% of the patients at follow up. No neurological deficits were found. Transient post-operative chest discomfort and compensatory hyperhidrosis (87%) were the most common complications. TES is an effective method for treating patients with HP, with a shorter operation time, fewer hospital days, and a better cosmetic result, as compared with the dorsal approach for thoracic sympathectomy.

Adolescent↗

PubMed1996

Fluorescein as an easy, low-cost, indirect, or reverse intraoperative marker to rule out perilymph versus local injection.

Clear fluid found in the dependent portions of the middle ear (round and oval windows) is generally assumed to be perilymph (PL). However, all clear fluid observed at middle ear exploration is not necessarily PL. PL should be distinguished from local injection. An accumulation of the local injection could be confused with perilymph fistula (PLF) diagnosis. There is no standard way of distinguishing perilymph from local injection, as both are clear, watery fluids. Fluorescein, tagged with a mixture of xylocaine and epinephrine (FLOTAX) was used as the local injection in 10 patients undergoing middle ear exploration for possible PLF.FLOTAX was injected into the vascular strip and ear canal skin in routine fashion. Transtympanic endoscopy and special Zeiss custom fluorescein filters were used to document any accumulation of fluid in the dependent portions of the middle ear and confirm whether any fluorescein (from the FLOTAX) was present. The middle ear was checked both before (endoscopically) and after raising the tympanomeatal flap. After the "local" injection, FLOTAX was observed to accumulate in dependent portions of the middle ear before raising the tympanomeatal flap in six of 10 ears. In the other four ears, FLOTAX slowly seeped into the middle ear cleft after the tympanomeatal flap was elevated and manipulated. Fluorescein can be used as an inexpensive, indirect intraoperative marker or "reverse test" for possible PLF. By eliminating a likely and common offender (local injection), any accumulation or reaccumulation of clear fluid that is not fluorescein tagged may more confidently be identified as possibly perilymph. The use of FLOTAX helps eliminate the confusion between the local injection and potential PLF. It does not in any way eliminate the possibility of other transudates from incisions, allergic reactions, or other manipulation of the tympanomeatal flap or middle ear mucosa.

Anesthetics, Local↗

PubMed1996

[Immune interference of enteroviruses to immune response of TOPV in subtroptical areas].

To study whether enteroviruses interfere with the immunoeffect of TOPV in subtroptical areas, a total number of 188 children were investigated 82 in summer, 106 in winter in two townships of Hui Dong County from 1992 to 1993. The carrier rates of enteroviruses and serum nutralization antibody titres of polio were tested before and after the children were vaccinated with TOPV. Data showed that the GMTs of poliovirus type I, II, III in winter were 2 to 7.1 times as much as those in summer after administration of one and three doses TOPV. Enterovirus carrier rates were 75.6% and 38.8% respectively in summer and winter before vaccination in health children. The GMTs of polio serum antibody in children without enteroviruses was 1.5 to 1.7 times as much as the GMTs of those with enteroviruses, and the difference was statistically significant. Overall, the results demonstrated that enterovirus infection interfered the immune response of vaccinates to TOPV to some extent. It was also suggested that supplemental immunization was the key measure in polio eradication program and should be conducted in winter or spring seasons.

Antibodies, Viral↗

PubMed1995

[Brain abscess as a complication of ear malignancy: a case report].

Ear infection is the most common cause of brain abscess. A suppurative process in the ear has access to the central nervous system by direct extension or through preformed pathways, either developmental, traumatic or pathologic, or by retrograde spread along the thromobophlebitic vein. Squamous cell carcinoma of middle ear or mastoid cavity is a rare disease and often associated with chronic otitis or chronic draining ear. Ear malignancy easily produces the destruction of temporal bone which may serve as a route for coexistent infection spreading into the brain. This paper reports a case of brain abscess occurring in a patient with temporal bone cancer. To the best of our knowledge, no more than three similar cases have been reported in the literature. The authors suggest that if an otogenic brain abscess is concomitant with infection and granulomatous mass in the ear, biopsy should be performed to rule out malignancy.

Brain Abscess↗