Biomedical subjects

W Y Lin

Publications and source records attributed to W Y Lin.

At least 163 records · Page 9Linked to original sources

PubMed1993

[Stress fracture of the ribs in amateur golfers diagnosed by Tc-99m MDP scintigraphy].

Golf has become a popular sport in Taiwan recently. Some amateur golfers suffer from back or chest pain, and a few of them have stress fractures of the ribs. Six amateur golfers suffering from back pain or chest pain, all male and right-handed players, aged from 28 to 39, were included in our study. The initial chest roentgenograms, including special views focusing on ribs, were all negative. Tc-99m MDP bone scan confirmed the diagnosis of stress fractures of the ribs. The intervals between playing golf and time of diagnosis were from 1 month to 5 months. In five cases, fracture sites in the left side were prominently located in the posterior aspect, a condition which may result from traction of the serratus anterior. Three cases with fracture sites in the right side had fractures prominently located in the lateral aspect, which may result from the repercussive force produced by the clubhead hitting the ground. Tc-99m MDP bone scan, with its high sensitivity, is useful in establishing the diagnosis of stress fracture.

Adult↗

PubMed1993

[The application of Tc-99m thyroid scintigraphy in congenital hypothyroidism].

Technetium-99m pertechnetate thyroid scans were generally applied to patients with thyroid diseases including hypothyroidism. We reviewed the thyroid images of 126 neonates who were suspected to have congenital hypothyroidism by neonatal TSH screening and of 2 cases by clinical suspicion. Of these, 62 cases were of transient hyperthyrotropinemia or were normal. Twenty-nine cases were of ectopic thyroid (M:F = 9:20). Two cases were hemiagenesis, both were female. Eight cases were athyrosis (M:F = 4:4). Two cases were secondary hypothyroidism (M:F = 1:1). Twenty-five cases were eutopic hypothyroidism (M:F = 13:12). We considered that the Tc-99m thyroid scan is convenient and useful in the differential diagnosis of the etiology of congenital hypothyroidism.

Congenital Hypothyroidism↗

PubMed1993

Quick diagnosis of hyperthyroidism with semiquantitative 30-minute technetium-99m-methoxy-isobutyl-isonitrile thyroid uptake.

Ten normal volunteers and 14 patients with hyperthyroidism had pinhole thyroid imaging 30 min after an intravenous injection of 10 mCi 99mTc-MIBI. Technetium-99m-MIBI thyroid uptake was calculated by the formula: [total counts with a region of interest (ROI) over the whole thyroid gland] divided by [(mean counts of every pixel in the neck soft tissue) x (total number of pixels in ROI over the whole thyroid gland)]. The results showed that the 30 min 99mTc-MIBI thyroid uptake ratios had positive relationships with the 24 hr 131I-thyroid uptake (r = 0.79), and that the patients with hyperthyroidism had significantly higher 30 min 99mTc-MIBI thyroid uptake than the normal volunteers (5.31 +/- 0.78 s.e.m. versus 2.35 +/- 0.14 s.e.m., p < 0.005 using the Mann-Whitney U-test). Technetium-99m-MIBI thyroid uptake may be useful for the rapid diagnosis of hyperthyroidism.

Adult↗

PubMed1993

[The evaluation of blood perfusion of lower extremities in patients with NIDDM by 133Xe muscle clearance test: a preliminary report].

In this study, we collected twenty NIDDM patients with impaired sensation and clinically suspected angiopathy over both lower extremities. All the patients underwent testing by means of the ultrasonic Doppler technique and were separated into two groups, group 1 with impaired blood flow, and group 2 with no significant impairment of blood flow. Ten normal persons were also included in this study (group 3). The results of the 133Xe muscle clearance test showed that the Q value of group 1 was 0.85 +/- 0.24 [mean +/- SE, ml (100g tissue min-1)], 1.05 +/- 0.31 in group 2 and 1.78 +/- 0.23 in group 3 of normal controls. After statistical analysis, there were significant differences in groups 1 and 2 relative to group 3 (p < 0.05), respectively. This preliminary result indicates that the 133Xe muscle clearance test may be an effective and convenient method to evaluate angiopathy of lower extremities in patients with NIDDM.

Adult↗

PubMed1993

[Muscle blood flow in lower limbs of healthy Chinese and variance according to sex and age].

The Xe-133 clearance method is used to measure muscle blood flow in the lower limbs to establish normal values and evaluate the variance between different sex and age groups in healthy Chinese. 99 healthy volunteers were included in this study and divided into three groups according to age and two groups according to sex. Group I: < 40 y/o, 34 persons; Group II: 41-60 y/o, 30 persons; Group III: > 60 y/o, 35 persons; male group: 51 persons; and female group: 48 persons. Intramuscular injection of Xe-133 saline solution in the anterior tibial muscle of the right leg was performed in all the volunteers to calculate muscle blood flow. The muscle blood flow is 3.21 +/- 1.29 ml/100 gm/min in Group I, 3.19 +/- 1.28 in Group II, 2.71 +/- 1.17 in Group III, 3.09 +/- 1.38 in male, and 2.96 +/- 1.24 in female. There was no significant difference in Groups I and II, or in the male and female groups using the Student's t test for unpaired data. However, a mild difference was observed between Groups I and III, and between Groups II and III (P values of 0.09 and 0.11 respectively). We conclude that there is no variance of muscle blood flow in the lower limbs between different sexes and the effect of aging on peripheral muscle blood flow is not significant before 60 in healthy Chinese.

Adolescent↗

PubMed1993

[Effective renal plasma flow in renal transplant rejection].

It is important to differentiate between cell-mediated (acute) and humoral (chronic) rejection in renal transplantation in order to initiate appropriate therapy. Since effective renal plasma flow (ERPF) provides a sensitive method of analyzing renal function, this test was undertaken to evaluate the possibility of differentiating acute and chronic rejections by ERPF. A total of 90 patients (no rejection: 33, acute rejection: 45, chronic rejection: 12) were retrospectively included in this study. ERPF was determined by performing comprehensive renal function test (Tauxe et al., 1980) and Student's unpaired t-test was used to evaluate the statistical difference (no rejection vs chronic rejection, no rejection vs acute rejection, acute rejection vs chronic rejection). The ERPF value of the no rejection group (228.9 +/- 119.2 ml/min) was significantly higher than the ERPF value of the acute rejection group (167.5 +/- 86.9 ml/min) and the chronic rejection group (137.2 +/- 60.2 ml/min) (P < 0.05). By in contrast, there was no significant difference between the acute rejection group and the chronic rejection group (P > 0.05). We concluded that ERPF value alone could not differentiate between acute rejection and chronic rejection in renal transplantation.

Adolescent↗

PubMed1992

Evaluation of immunochemical changes in ovalbumin due to reaction with oxidizing methyl linoleate by an enzyme linked immunosorbent assay.

1. An enzyme linked immunosorbent assay (ELISA) was used to study the immunochemical properties of ovalbumin altered by the reaction with oxidizing methyl linoleate under various conditions. 2. The results indicated that the values of ELISA decreased with an increase of the degree of ovalbumin following reaction with oxidizing methyl linoleate. 3. The antigenicity of ovalbumin, when examined by competitive inhibition assay, reduced about 20-fold as compared with native ovalbumin when reacted with oxidizing methyl linoleate at 50 degrees C and water activity (0.68) for 30 days.

Binding, Competitive↗

PubMed1992

PKC epsilon-related kinase associates with and phosphorylates cytokeratin 8 and 18.

A 40-kD protein kinase C (PKC)epsilon related activity was found to associate with human epithelial specific cytokeratin (CK) polypeptides 8 and 18. The kinase activity coimmunoprecipitated with CK8 and 18 and phosphorylated immunoprecipitates of the CK. Immunoblot analysis of CK8/18 immunoprecipitates using an anti-PKC epsilon specific antibody showed that the 40-kD species, and not native PKC epsilon (90 kD) associated with the cytokeratins. Reconstitution experiments demonstrated that purified CK8 or CK18 associated with a 40-kD tryptic fragment of purified PKC epsilon, or with a similar species obtained from cells that express the fragment constitutively but do not express CK8/18. A peptide pseudosubstrate specific for PKC epsilon inhibited phosphorylation of CK8/18 in intact cells or in a kinase assay with CK8/18 immunoprecipitates. Tryptic peptide map analysis of the cytokeratins that were phosphorylated by purified rat brain PKC epsilon or as immunoprecipitates by the associated kinase showed similar phosphopeptides. Furthermore, PKC epsilon immunoreactive species and CK8/18 colocalized using immunofluorescent double staining. We propose that a kinase related to the catalytic fragment of PKC epsilon physically associates with and phosphorylates cytokeratins 8 and 18.

Cytoskeleton↗

PubMed1992

Detection of localized Salmonella infection by gallium-67 citrate scan.

Fifteen cases (9 males, 6 females, ages: 18-73 y/o) of salmonella bacteremia were referred for a Gallium-67 citrate (Ga-67) scan to detect the focal site(s) of salmonella infection. Among them, 8 were finally proved to have focal infection(s). Their underlying diseases were systemic lupus erythematous (SLE, 4 cases), malignancies (2 cases), immunocompromise (1 case) and unknown disease (1 case). The focal infections detected were septic arthritis in 6, soft tissue abscesses in 4 and lung abscesses in 2. This report suggests that Ga-67 scan is of great value in detection of localized salmonella infection.

Adolescent↗

PubMed1992

[Phagocytosis of the reticuloendothelial system in diabetes mellitus].

It has been assumed that patients with diabetes mellitus (DM), who are usually susceptible to bacterial infections, have a depression of the antibacterial defense mechanism. This study was undertaken to substantiate the hypothesis that phagocytosis of the reticuloendothelial system (RES) is depressed in diabetic patients. It is believed that intravenously injected colloidal suspensions whose particles are unable to pass through the capillary barrier will be phagocytized mainly by the reticuloendothelial cells in the liver and spleen. In the present study, the RES phagocytic index (RESPI) was measured in 48 subjects: 20 normal controls and 28 patients with DM. Measurements were based on the rate of disappearance (T1/2) of radioactivity in the heart (blood pooling) after rapid I.V. injection of 3mCi of Tc-99m phytate (2mg phytate). Using a gamma camera, sequential images of the liver and heart were obtained, and computer-generated time-activity curves were established. The T1/2 was then calculated. Our results revealed that the RESPI values in the DM group were significantly increased as compared to the normal control group (normal control = 4.60 +/- 1.01; DM = 6.78 +/- 3.83; P < 0.05). This prolonged half-disappearance time of blood radioactivity in diabetic patients is interpreted as a reflection of impaired phagocytotic efficiency in the reticuloendothelial system. The results of this preliminary study add support to the in vivo evidence explaining the increased susceptibility to infection in diabetic patients.

Adolescent↗

PubMed1992

[Bone mineral density in patient with renal transplant].

Progressive renal failure may cause disturbance of mineral metabolism. Successful renal transplantation may correct many features of disturbance of calcium and phosphorus metabolism. Dual photon absortiometry (DPA) provides a noninvasive method for the serial measurements of bone mass of the vertebral bodies. Using this method, bone mineral density (BMD) was detected and evaluated in patients with renal transplants. In this study, BMDs of lumbar vertebrae 2 to 4 were measured and the mean value was presented as gm/cm2. Forty seven patients (over 40 years of age) with renal transplants and 103 normal controls of a similar age group were included in this study. Surprisingly, no significant difference in bone mineral density was found between the patients with renal transplant and the normal controls in our preliminary study.

Adult↗

PubMed1992

The effects of hyperthyroidism on oesophageal motility.

This study, evaluating the effects of hyperthyroidism (HT) in oesophageal motility, depended on an oesophageal radionuclide transit test. A modified standard method was used to calculate: (a) total mean transit time (MTT), (b) residual fraction (RF) and (c) retrograde index (RI) in a supine position. Eighteen untreated patients with HT and 25 normal volunteers (NV) with a similar age distribution were included in this study. The results showed that oesophageal motility in patients with HT was worse than in the normal controls (P < 0.05 by Student's t-test). The correlation of MTT, RF and RI with size and function of thyroid glands in the patients with HT were calculated to explain the effects of HT in oesophageal motility. The results showed that neither the size nor the function of the thyroid glands in HT affected oesophageal motility.

Adult↗

PubMed1992

I-131 NP-59 adrenal cortical scintigraphy in suspected primary aldosteronism.

Dexamethasone suppression [Iodine-131] 6-Beta-Iodomethy1-19- Norcholesterol (I-131 NP-59) adrenal cortical scintigraphy was performed in 35 patients with suspected primary aldosteronsim, between May 1983 and June 1990. Based on clinical, biochemical, radiographic and pathologic data, the diagnostic accuracy of primary aldosteronism from I-131 NP-59 adrenal cortical scintigraphy was evaluated. The sensitivity, specificity, positive predictive accuracy and negative predictive accuracy was 78.9%, 100%, 100% and 80% respectively. We conclude that I-131 NP-59 adrenal cortical scintigraphy is an accurate and noninvasive technique for the diagnosis of suspected primary aldosteronism.

Adosterol↗

PubMed1992

Comparison between thallium-technetium subtraction scan and other imaging modalities in the preoperative localization of abnormal parathyroid glands.

A total of 15 patients who underwent total neck exploration for hyperparathyroidism were studied with four different imaging modalities: (a) Tl-201/Tc-99m subtraction scan (SS), (b) ultrasonography (US), (c) computed tomography (CT) and (d) magnetic resonance imaging (MRI). Accuracy for locating enlarged parathyroid(s) was 60.0% by SS, 60.0% by US, 33.3% by CT and 71.4% by MRI. Our results suggested that at present none of the imaging modalities was adequate on its own to locate all enlarged parathyroid gland(s) in patients with hyperparathyroidism.

Adult↗

PubMed1991

Differential innervation patterns of three divisions of frog auditory midbrain (torus semicircularis).

The connectivity pattern of the laminar, principal, and magnocellular nuclei of the frog torus semicircularis (TS) was investigated. A small amount of horseradish peroxidase was injected focally into individual divisions of the TS and anterograde and retrograde transport patterns were observed. Results of our tracing study showed that these divisions of the TS possessed distinct innervation patterns. The principal nucleus appeared to be the primary input port of the TS receiving extensive inputs from all caudal brainstem auditory nuclei bilaterally, but especially from the contralateral dorsal medullary nucleus and the ipsilateral superior olivary and lateral lemniscus nuclei. Descending projection to this nucleus was limited to that from the posterior thalamic nucleus. In contrast, the laminar nucleus, but even more markedly the magnocellular nucleus, received extensive descending inputs from numerous structures in the dorsal thalamus and less pronounced ascending afferents from caudal brainstem auditory nuclei. Similar to the afferent connection patterns, the efferent projections originating from these three toral divisions differed substantially. The principal nucleus gave restricted ascending projections, limited mainly to the caudal region of the posterior thalamic nucleus, a region important in processing spectral information of complex sounds, and the pretectal gray. Its descending projection was also somewhat restricted, being limited to the superior olivary and lateral lemniscus nuclei. The laminar nucleus and especially the magnocellular nucleus gave robust descending as well as ascending projections; these nuclei serve as the main output paths for the TS and provide the main routes by which auditory input reaches the central thalamic nucleus, a structure previously shown to be involved in temporal information processing.

Afferent Pathways↗

PubMed1991

Terbium(III) luminescence study of the spatial relationship of tryptophan residues to the two metal ion binding sites of Escherichia coli glutamine synthetase.

The luminescence of Tb(III) was used to explore the topography of the metal ion sites of Escherichia coli glutamine synthetase and the relationship between these sites and tryptophan residues of the enzyme. By irradiation of tryptophan residues at 295 nm and measurement of the resulting Tb(III) luminescence at 544 nm, a biphasic curve was obtained upon titrating apoenzyme with Tb(III) indicating sequential binding of Tb(III) ions to the two binding sites of glutamine synthetase. The luminescence intensity was greater in the second region of the titration curve which is mostly due to energy transfer from Trp-158 to the second Tb(III) binding site of the enzyme. By use of the Förster equation for energy transfer from donor Trp to acceptor Tb(III), distances from Trp-57 to Tb(III) at the n1 and n2 sites were calculated, by using a mutant enzyme in which Trp-158 was replaced by Ser, to be 16.4 and 15.7 A, respectively; distances from Trp-158 to Tb(III) at the n1 and n2 sites were calculated, by using a mutant enzyme in which Trp-57 was replaced by Leu, to be 16.8 and 9.5 A, respectively. All the distances are in reasonably good agreement with the crystal structure distances from Salmonella typhimurium glutamine synthetase except the distance from Trp-158 to the second Tb(III) binding site. The discrepancies may result from a slightly different conformation of glutamine synthetase in solution and in the crystal and/or a slightly different conformation for trivalent Ln(III) binding compared to divalent Mn(II) binding.

Binding Sites↗

PubMed1991

Fluorescent probes for measuring the binding constants and distances between the metal ions bound to Escherichia coli glutamine synthetase.

TNS, 2-p-toluidinylnaphthalene-6-sulfonate, has been used as a fluorescent probe to determine the binding constants of metal ions to the two binding sites of Escherichia coli glutamine synthetase (GS). TNS fluorescence is enhanced dramatically when bound to proteins due to its high quantum yield resulting from its interactions with hydrophobic regions in proteins. The fluorescence energy transfer from a hydrophobic tryptophan residue of GS to TNS has been detected as an excitation band centered at 280 nm. Therefore, TNS is believed to be bound to a hydrophobic site on the GS surface other than the active site and is located near a hydrophobic Trp residue of GS. GS binds lanthanide ions [Ln(III)] more tightly than either Mn(II) or Mg(II), and the binding constants of several lanthanide ions were determined to be in the range (2.1-4.6) x 10(10) and (1.4-3.0) x 10(8) M-1 to the two metal binding sites of GS, respectively. The intermetal distances between the two metal binding sites of GS were also determined by measuring the efficiencies of energy transfer from Tb(III) to other Ln(III) ions. The intermetal distances of Tb(III)-Ho(III) and Tb(III)-Nd(III) were 7.9 and 6.8 A, respectively.

Binding, Competitive↗

PubMed1991

Terbium(III) luminescence study of tyrosine emission from Escherichia coli glutamine synthetase.

Radiationless energy transfer from tyrosine to Tb(III) in Escherichia coli glutamine synthetase and its two mutants (W57L and W158S) has been utilized to assess the tyrosine residue(s) responsible for the observed tyrosine emission and to investigate its spatial relationships to the two metal binding sites of GS. The interference from tryptophan fluorescence was removed by chemical modification of the tryptophan residues by N-bromosuccinimide (NBS). The Tyr-Tb(III) distances measured by using Förster energy-transfer theory were in good agreement among the three enzymes with average distances of 10.7 and 11.2 A from Tyr to the two metal binding sites. The pKa value for the ionization of tyrosine was determined from fluorescence titration experiments to be approximately 10 for both mutant enzymes. The similarities in pKa values and Tyr-Tb(III) distances observed for all three enzymes lead to the conclusion that the same tyrosine residue(s), is (are) most likely responsible for the Tyr emission. According to the crystal structure distances from tyrosine residues to the two metal binding sites of GS, it is believed that Tyr-179 is the main contributor to the observed Tyr emission. The fact that an intense Tyr emission was observed for W57L GS but not for W158S GS indicates that Trp-57 is much more effective than Trp-158 in quenching the Tyr-179 emission probably through a Förster-type energy transfer. Furthermore, modification of Trp-57 by NBS causes no significant increase in Tyr-179 emission while replacement of Trp-57 by leucine does. This may indicate that oxidized Trp-57 is also an effective quencher for Tyr-179 emission.

Binding Sites↗