Biomedical subjects

M C Lee

Publications and source records attributed to M C Lee.

At least 199 records · Page 11Linked to original sources

PubMed1995

99mTc-HMPAO labeled leukocyte SPECT in intracranial lesions.

BACKGROUND: Scintigraphy with 111In (indium-111)-oxine or 99mTechnetium-hexamethylpropyleneamine oxime (99mTc-HMPAO) labeled leukocytes has been used to differentiate brain abscess from brain tumor. However, there are false positive or false negative results from planar scintigraphic images. So a more specific and sensitive scintigraphic technique needs to be developed. METHODS: Planar and single photon emission computed tomography (SPECT) images were obtained and reviewed in 14 patients with intracerebral ring-enhancing lesions on computed tomography (CT) or magnetic resonance imaging (MRI). In all patients, diagnosis was confirmed by histopathologic examination. The effect of steroids or antibiotics on scintigraphic finding was examined. RESULTS: Abscess was confirmed in six patients, tumor in six, tuberculoma and cysticercosis in one each, respectively. In all the patients with abscess, SPECT showed increased focal activity irrespective of steroid or antibiotic therapy. Increased radioactivity, which could not be detected on planar images, could be identified in two patients with abscess. In three of the six patients with tumor, radiolabeled leukocytes did not accumulate in the tumor. In the other three patients with tumor, SPECT showed focally increased activity that was less intense than the activity shown in the patients with abscess. CONCLUSIONS: 99mTc-HMPAO labeled leukocyte SPECT is useful for the differential diagnosis of intracerebral ring-enhancing lesions, and the use of steroids or antibiotics does not influence the sensitivity of SPECT. Diagnostic sensitivity of scintigraphy with labeled leukocytes could be improved by SPECT in addition to planar image.

Adult↗

PubMed1995

Development of bone marrow immunoscintigraphy using a Tc-99m labeled anti-NCA-95 monoclonal antibody.

We evaluated the monoclonal antibody CEA-79.4 against carcinoembryonic antigen as an immunoscintigraphic agent for assessing the state of the bone marrow. Western blotting of human granulocyte extracts with the antibody could confirm that the binding was with the epitope of NCA-95. Immunocytochemical staining of bone marrow aspirates revealed specific uptake of this antibody by granulopoietic cells. The affinity constant was 2-9 x 10(9) L/mol. Immunoscintigraphy using 99mTc-labeled CEA-79.4 in a normal volunteer revealed high uptake in the bone marrow as compared to other organs.

Antibodies, Monoclonal↗

PubMed1995

Poor renal uptake of Tc-99m DMSA and Tc-99m MDP in a patient with Fanconi syndrome and near normal glomerular filtration rate.

The authors present a patient with Fanconi syndrome who demonstrated poor renal uptake of Tc-99m DMSA and high urinary concentration of the tracer. Tc-99m DTPA imaging was normal and the creatinine clearance was only minimally decreased. These findings suggest that Tc-99m DMSA may be accumulated in the kidney by glomerular filtration and subsequent tubular reabsorption. A Tc-99m MDP bone scan showed faint renal uptake, as well as diffuse high skeletal uptake, particularly in the spine, demonstrating that the metabolic bone disease associated with Fanconi syndrome can be one of the causes of poor renal visualization on a bone scan.

Bone and Bones↗

PubMed1995

Evaluation of bone metastases by Tc-99m MDP imaging in patients with stomach cancer.

The authors conducted a retrospective review of 234 bone scans of stomach cancer patients who had been diagnosed at the Seoul National University Hospital. In 106 of the 234 cases (45.3%), there were abnormal bone scan results, suggestive of bone metastases. The most common site of bone metastases was the spine, followed by the ribs, pelvis, femur, and skull. These sites were similar to those known for other malignant diseases. The incidence of bone metastases increased according to the duration of disease, especially within 12 months after diagnosis in patients with stage III gastric cancer. The incidence of bone metastases increased as the clinical stage increased. However, the incidence of metastases did not relate to gastric cancer pathologic type. The authors found 6 cases of "superscan" in the 234 bone scans (2.6%). The bone scan findings correlated positively with the level of serum alkaline phosphatase.

Bone Neoplasms↗

PubMed1995

Obstructive leiomyoma of the female urethra: report of a case.

We report a case of leiomyoma of the female urethra and review the literature. A mass protruding from the urethral meatus during voiding caused dysuria. Urodynamic study showed an obstructive pattern with low maximum urine flow and high detrusor pressure in initiating voiding. Cystourethroscopy revealed a mass extending from the proximal segment of the left lateral urethral wall into the bladder. At transurethral resection of the tumor 12.2 gm. of tissue were excised. Histopathological studies confirmed urethral leiomyoma. Surgery completely resolved the original symptoms of dysuria.

Female↗

PubMed1995

Cloning and expression of the VP1 major capsid protein of diabetogenic encephalomyocarditis (EMC) virus and prevention of EMC virus-induced diabetes by immunization with the recombinant VP1 protein.

The development of diabetes in mice induced by encephalomyocarditis (EMC) virus provides the best experimental evidence that viruses have an aetiological role in the pathogenesis of this disease. The major capsid protein (VP1) of EMC virus is important for both the attachment of the virus to pancreatic beta cells and for the determination of antigenicity. This experiment was initiated to clone the gene for the major capsid protein, VP1, of the diabetogenic EMC (EMC-D) virus, express the VP1 protein, and test whether the recombinant VP1 protein can prevent development of EMC-D virus-induced diabetes in mice. We successfully cloned the VP1 gene of the EMC-D virus in the expression vector pRSET and subsequently expressed the protein in Escherichia coli. The recombinant VP1 protein was then purified by affinity chromatography. Five- to six-week-old male SJL/J mice were immunized intraperitoneally with purified VP1 protein and then challenged after various intervals with highly diabetogenic EMC-D virus. None of the VP1-immunized mice developed diabetes, irrespective of the interval between immunization and virus challenge, whereas 80 to 95% of the EMC-D virus-infected control mice did develop diabetes. All of the VP1-immunized mice showed intact pancreatic islet architecture, whereas most of the infected control mice showed severe beta cell necrosis and lymphocytic infiltration of their pancreatic islets. On the basis of these observations, we conclude that the recombinant VP1 protein of EMC-D virus can completely prevent the development of EMC-D virus-induced diabetes in mice.

Amino Acid Sequence↗

PubMed1995

The use of arch index to characterize arch height: a digital image processing approach.

Attempts to evaluate foot arch types from footprint parameters have yielded conflicting results in the past. This could be caused by the uncertainty inherent in the definition of some footprint parameters and the inaccuracy during the footprint acquisition and the parameter calculation phases of the traditional methods. In order to avoid these problems, digital image processing methods were used to acquire and to calculate the Arch Index (AI), a parameter which is robust in its definition. A significant correlation (r = -0.70, p < 0.0001) was found between AI and arch height. Therefore this study confirms that foot arch type does correlate with the footprint parameter, AI. This was further revealed by a new parameter, the Modified Arch Index (MAI), which incorporates foot pressure information in the evaluation. MAI not only correlated well with arch height (r = -0.71, p < 0.0001) but appeared to characterize abnormal foot types better than AI.

Adult↗

PubMed1995

Sensory changes in the ipsilateral extremity. A clinical variant of lateral medullary infarction.

BACKGROUND: Classically, patients with unilateral lateral medullary infarction exhibit sensory abnormalities over the ipsilateral face and contralateral hemibody. As a variant, bilateral or contralateral facial sensory changes can be seen. However, sensory changes in the ipsilateral extremities are extremely rare. CASE DESCRIPTIONS: We describe three patients with lateral medullary syndrome in whom impaired deep sensation in the ipsilateral limbs was found. MRI results showed that the infarcts were located superficially in the lateral (case 1) and dorsal (cases 2 and 3) areas of the lower medulla, which probably involved the ascending or crossing dorsal column sensory tracts. CONCLUSIONS: Although rare, impaired ipsilateral deep sensation is encountered in patients with lateral medullary infarction syndrome.

Adult↗

PubMed1995

Syndromes of pontine base infarction. A clinical-radiological correlation study.

BACKGROUND AND PURPOSE: Although there have been sporadic reports of lacunar syndromes due to pontine base infarction, studies of clinical-radiological correlation in sufficient numbers of patients have not yet been reported. METHODS: We studied the clinical features of 37 patients with acute infarcts that mainly involved the base of the pons and correlated the clinical syndromes with the radiological findings. RESULTS: The clinical presentations included pure motor hemiparesis (PMH) in 17, sensorimotor stroke in 3, ataxic hemiparesis (AH) in 4, and dysarthria-clumsy hand (DA-CH) syndrome in 6 patients. Variants of AH included 1 patient with dysarthria-hemiataxia and 2 with quadrataxic hemiparesis, and in 4 patients dysarthria-facial paresis syndrome was considered a variant of DA-CH syndrome. Hypertension was the single most common and important risk factor, and the pathogenetic mechanisms of ischemia were likely to be small arterial (lacunar) occlusion or basilar atheromatous branch occlusion in most of the patients. Our clinical-radiological correlation study suggested that large lesions involving the paramedian caudal or middle pons correlate with severe hemiparesis (PMH), whereas lesions of similar size located in the paramedian rostral pons tended to produce DA-CH syndrome. Lesions producing AH were located variously but tended to spare the pyramidal tracts. The prognosis of these patients is fair or good, although residual hemiparesis remained in patients with initially severe hemiparesis. CONCLUSIONS: Our data suggest that the various lacunar syndromes that follow pontine base infarcts reflect the balance of the involvement of the corticospinal, corticopontocerebellar, and corticobulbar tracts. Analysis of radiological findings aids in determining the clinical-anatomic correlation in patients with pontine base infarction.

Adult↗

PubMed1995

[Psychosocial responses of infertile couples attending an assisted reproduction program].

The purpose of this study was to evaluate gender differences in the psychosocial responses of 85 couples who attended the assisted reproduction program at Chung Shan Medical & Dental College Hospital from September 1991 to February 1992. The infertile couples were investigated by a self-administered structured questionnaire about demographic data, infertility history, and psychosocial responses and 75 couples completed the questionnaire. The average age of husbands was 35.0 years/and wives, 31.6 years. The average duration of infertility and treatment was 52.7 and 34.6 months, respectively. Parental expectation was the leading source of stress for men, while women counted being unable to meet childbearing demands as the main source of stress. Infertile women showed a higher psychosocial distress than their partners on the global measures and all the subscales of the infertility questionnaire and psychiatric symptoms test. Except for hostility, the differences between couples in subscales of self-esteem/body image, guilty, and all psychiatric symptoms reached statistical significance (p < 0.05). Among varied psychosocial responses of infertile couples, concordant response was demonstrated only in response to sexuality and physical condition. We consistently conclude with previous reports that infertile women showed a higher level of distress than their spouses, and that men and women displayed different psychosocial responses to infertility.

Adult↗

PubMed1995

Technetium-99m-labeled antigranulocyte antibody bone marrow scintigraphy.

UNLABELLED: Although bone scintigraphy is a sensitive method for detecting skeletal metastases, it is often equivocal for metastases due to poor specificity. This study evaluates 99mTc-antigranulocyte antibody (AGA) bone marrow scintigraphy in differentiating malignant from benign lesions, in 42 patients with skeletal tumors who had equivocal bone scans. METHODS: AGA scans performed approximately 1 wk after 99mTc-MDP bone imaging were visually assessed for the presence of concordant marrow defects. Final diagnoses were made from radiological results, follow-up bone scans or clinical evaluation for 12 mo or longer. RESULTS: The final diagnoses were: skeletal metastasis (19 patients), no metastasis (20 patients) and unconfirmed (3 patients). AGA scans could not determine the presence of a concordant defect in three patients because of overlying liver activity or previous irradiation of the region. Seventeen patients had bone marrow defects concordant with bone scan lesions, whereas 15/19 patients without metastasis had normal AGA scans. The sensitivity and specificity of AGA for detecting skeletal metastases were 100% and 79%, respectively. CONCLUSION: AGA scans had a low incidence of skeletal metastases in patients who had equivocal bone scans. Although a concordant marrow defect increases the possibility of metastasis, further radiological investigation to exclude benign disease is warranted.

Antibodies, Monoclonal↗

PubMed1995

[Evaluation of the effects of a general medical course for non-medical university students].

In order to evaluate the effects of a general medical course on students' related attitudes and knowledge, 186 students who took the general medical course in the National Chung-Hsing University or the Private Fung-Chia University were asked to fill in a structured questionnaire both before and after their course during February, 1993 and January, 1994. The average age of the 177 students who completed the questionnaire on both occasions was 21.9 years; 109 were males and 68 were females. Two thirds of the students indicated that they would like to learn more about health and medical sciences as the main reason for taking the course. Before the class, the leading two perceptions of health given by students were no biopsychological problem (54.2%) and no biomedical problem (18.6%), while no biopsychological problem (55.4%) and no biopsychosocial problem (23.7%) were the leading two perceptions afterwards. After the course, about 21% of students counted health as the greatest concern in their lives, while only 16% did before the class. At first only 18.6% of students considered life style as the most important contributing factor to human health, but the frequency increased to 28.2% at the end of the class. Regarding knowledge on health and medical care, mean scores in all five domains of knowledge were significantly higher after than before the course. The general medical curriculum was welcomed and highly valued by students based on their evaluations after the class. We concluded that university students' attitudes toward and knowledge on health and medical care can be significantly increased by a general medical curriculum.

Adult↗

PubMed1995

Proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NORs) in benign, atypical and malignant meningiomas.

Expression of proliferating cell nuclear antigen (PCNA) and numbers of nucleolar organizer regions (NORs) were studied by immunohistochemistry and the silver staining technique in 99 meningiomas and related to histopathologic grading, recurrence and their predictive value for recurrence. The results indicated that there was a significant correlation between PCNA or AgNORs and histopathologic grading of meningiomas. Slightly higher expression of PCNA in atypical meningiomas was correlated with the increased recurrence rate; however, expression of PCNA and numbers of AgNORs in meningiomas are not reliable criteria to predict tumor recurrence.

Humans↗

PubMed1994

Mapping studies of two G protein-coupled receptor genes: an amino acid difference may confer a functional variation between a human and rodent receptor.

We recently isolated two orphan human G protein-coupled receptor genes designated GPR1 and GPR6. The gene GPR1 was shown to be transcribed abundantly but only in the hippocampus. Here we report the cloning of the rat GPR1 gene and report the absence of expression in hippocampus, demonstrating a functional variation for this receptor in these two species. The evolutionary history of an important sequence difference in the gene GPR1 in primate and rodent species has been examined. In contrast extensive mapping of gene GPR6 mRNA in rat brain was in keeping with the described distribution in human brain.

Amino Acid Sequence↗

PubMed1994

Inactivation of Acacia confusa trypsin inhibitor by site-specific mutagenesis.

Native Acacia confusa trypsin inhibitor (ACTI) contains two disulphide bonds; one is an intrachain disulphide bond (Cys40-Cys86), located in the A-chain, while the other is an interchain disulphide bond (Cys133-Cys141) connecting the A- and B-chain; the inhibitor consists of 175 amino acid residues, 136 residues in the A-chain and 39 residues in the B-chain. The putative reactive site of ACTI is located at Lys64, while for all other Kunitz family trypsin inhibitors it is at Arg64. When the Lys64 residue of ACTI was converted into Ile or Arg by site-specific mutagenesis, the K64I mutant completely lost its inhibitory activity but the K64R mutant retained most of its inhibitory activity. The C133G mutant lost its inhibitory activity while the C40G mutant did not. This suggests that the interchain disulphide bond (Cys133-Cys141) linking two beta-strands of the six-strand beta-barrel is essential for ACTI inhibitory activity, while the intrachain disulphide bond (Cys40-Cys86) connecting the two loops is non-essential.

Acacia↗

PubMed1994

Neuropeptide Y functions as a physiologic regulator of cephalic phase acid secretion.

Neuropeptide Y (NPY) has been established as a potent orexigenic peptide, and recent studies suggest that NPY stimulates cephalic phase secretion as well. However, it is not known whether NPY's effects are pharmacologic or physiologic. In order to determine the physiologic significance of NPY, we examined the effects of two putative NPY receptor antagonists, PYX-1 and PYX-2, on sham feeding and gastric acid secretion in dogs. Our results demonstrate that intracerebroventricular (i.c.v.) injection of PYX-1 and PYX-2 at 1000 pmol/kg doses significantly suppresses the gastric acid response to sham feeding in dogs. The volumes sham fed were not significantly altered with i.c.v. administration of the antagonists. Peripheral administration did not affect acid secretion nor sham feeding volumes. Our data suggest that central administration of the novel NPY antagonists, PYX-1 and PYX-2, results in significant suppression of acid secretion in dogs. This supports our hypothesis that NPY functions as a physiologic modulator of cephalic phase acid secretion.

Animals↗

PubMed1994

Changes in lumbar disc angles of Chinese subjects from upright to flexion.

STUDY DESIGN: This study analyzed the sizes and angles of vertebrae and discs in Chinese subjects. Lateral lumbar spine radiograph films were taken of subjects in upright and 60 degrees flexion positions to evaluate disc height and angle changes. OBJECTIVES: This study sought to gather data regarding the contribution of each segment to lumbar lordotic curvature in upright posture, and angle changes of individual segments from upright to flexion positions. SUMMARY OF BACKGROUND DATA: Although the dimensions of vertebrae and discs have been measured, little has been done regarding in vivo measurements of lumbar lordotic curvature formation, especially during flexion. In addition, no data are available for the Chinese population. METHODS: Five men and six women were studied. The lateral lumbar spine radiograph films were taken for upright and 60 degrees flexion positions. The dimensions of vertebral bodies and discs and lumbosacral angle were measured. RESULTS: The disc heights ranged from 0.7 to 1.2 cm in upright posture. Mean disc angle ranged from 9 degrees to 14 degrees in men and 6 degrees to 13 degrees in women. The lowest three segments (L3-L5) contributed 80% to 90% of the lumbosacral angle (L1-S1), which was approximately 47 degrees. Mean sacral horizontal angle was 35 degrees. From upright to 60 degrees flexion positions, all disc angles decreased uniformly from a total of 53 degrees +/- 6 degrees to 11 degrees +/- 12 degrees in men and 46 degrees +/- 11 degrees to 0 degrees +/- 18 degrees in women. CONCLUSIONS: The dimensions of lumbar vertebral bodies and discs, in upright and flexion positions, appear to be similar between Chinese and Western populations.

Adult↗

PubMed1994

Polysaccharide conjugate vaccine responses in bone marrow transplant patients.

Bone marrow transplant patients have impaired responses to pure polysaccharide (PS) vaccines and are at an increased risk for disease caused by PS encapsulated pathogens such as Haemophilus influenzae type B (HIB) and Streptococcus pneumoniae. We immunized 35 BMT patients (21 allogeneic and 14 autologous) ages 2-45 years with pure PS pneumococcal (Pnu-imune 23) HIB-conjugate (HibTITER), and tetanus toxoid vaccines. Patients were assigned to receive vaccines at either 12 and 24 months after transplantation or at 24 months only. Only 19% of all enrolled patients developed protective antibody concentrations (> or = 0.300 microgram antibody nitrogen/ml) to the 6 pneumococcal serotypes measured after the 24-month immunization. Poor response to pneumococcal vaccine was not different for the 2 study groups and was similar to previous studies. In contrast, HIB-conjugate vaccine elicited protective concentrations of antibody (> or = 1.0 microgram/ml) in 56% of patients after 1 dose and in 80% after 2 doses. The group that received 2 doses of HIB-conjugate vaccine had a significantly higher geometric mean antibody concentration of 14.5 micrograms/ml as compared with 1.43 micrograms/ml for those receiving only 1 dose (P = 0.012). Responses to tetanus toxoid vaccine were similar to HIB-conjugate vaccine, with a booster response documented after the second dose. In summary, 2 doses of HIB-conjugate vaccine given at 12 and 24 months after transplantation produced protective antibody concentrations in 80% of patients. While the response to pure PS pneumococcal vaccine was poor, the results with HIB-conjugate vaccine suggest that future pneumococcal conjugate vaccines may also benefit BMT patients.

Adolescent↗