Biomedical subjects

K M Liu

Publications and source records attributed to K M Liu.

At least 37 records · Page 2Linked to original sources

PubMed1997

Early genetic and cellular responses in the smooth muscle layer of obstructed ureters in a rat model of obstructive uropathy.

OBJECTIVE: To investigate the early genetic and cellular responses in the smooth muscle layer of completely obstructed ureters, and to determine whether myocytes proliferate (hyperplasia) in the ureters during the early stage of obstructive uropathy. MATERIALS AND METHODS: The study comprised 35 female Sprague-Dawley rats which had undergone unilateral ligation of their ureters. After ureteric ligation, five rats each were killed and examined at 0.5, 1, 2, 4, 8, 16 and 24 h after ligation. The proximal portion of the ureters was prepared for light and electron microscopy. The expression of c-Fos, c-Jun, c-Myc and Ki-67 antigen was assessed immunohistochemically. RESULTS: c-Fos and c-Jun were detected 2 h after ligation and the expression of these two proteins reached a maximum after 4 h, becoming undetectable 16 h after ligation. The expressions of c-Fos and c-Jun were strongly correlated (r = 0.9854, P < 0.001). The expressions were of c-Myc and Ki-67 antigen was not detected within 24 h after ureteric ligation. The amount of rough endoplasmic reticulum (rER) in the ligated ureters increased soon after complete ligation and the increase continued throughout the period of ureteric obstruction (r = 0.9699, P < 0.001). The change in rER was also significantly correlated with the expression of c-Fos and c-Jun within 8 h after ligation. CONCLUSION: The expression of c-Fos and c-Jun, but not c-Myc, might contribute to the hypertrophy of the ureteric smooth muscle layer during the course of complete ureteric obstruction. There is no hyperplasia in ureteric smooth muscle in the early stages of obstructive uropathy.

Animals↗

PubMed1997

Capgras' syndrome in a patient with vascular dementia: a case report.

Capgras' syndrome is characterized by a subjective certainty that a familiar person has been replaced by an identical double. This syndrome has been observed in psychiatric and neurological diseases, and has been reported in several cases of dementia of the Alzheimer type. Here, we present a patient with vascular dementia in whom Capgras' syndrome developed in the early stages of dementia, and who exhibited violence. This case suggests that Capgras' syndrome can occur in vascular dementia. In older patients with this syndrome, dementia should also be considered in its differential diagnosis. In addition, patients with Capgras' syndrome should be evaluated for violent potential.

Aged↗

PubMed1996

Logistic analysis of the effects of shovel trait on Carabelli's trait in a Mongoloid population.

Mongoloid populations differ from Caucasoids by having a high prevalence of shovel trait and a low prevalence of Carabelli's trait. This study was conducted to investigate the effects of the shovel trait on Carabelli's trait in a Mongoloid population. The research design sought a population that resides in an isolated area and exhibits low admixture with neighboring populations. The Mongoloid group selected for study was the Bunun tribe of aborigines who inhabit an alpine area in Taiwan. The effects of sex and age on Carabelli's trait were controlled in this investigation, as was the association between tooth size and Carabelli's trait. Results show that males were more likely to have Carabelli's trait expressed on teeth than females. The buccolingual diameter of Carabelli's trait teeth was larger than that of teeth without the trait. After adjusting for sex, age, and tooth size, the existence of the shovel trait increased the likelihood of having Carabelli's trait by a factor of three, an effect that is significant.

Adolescent↗

PubMed1996

Physical aggression and associated factors in probable Alzheimer disease.

Aggressive behavior is thought to be pervasive among and devastating to demented patients and their caregivers. This study investigated the prevalence of physical aggression in demented inpatients with Alzheimer disease (AD). Additionally, the characteristics and psychiatric symptoms that may be associated with aggression were tested. Forty-seven patients with probable AD were included in this study. Physical aggression was reported in 27 (57.4%) of the patients. These patients were older, had a later onset of dementia, and had a higher prevalence of misidentification, activity disturbances, and day/night disturbance. The relationship between these factors and physical aggression needs further clarification, which may help provide effective predictors and treatment of the aggressive behavior.

Aged↗

PubMed1996

[Characteristics of dementia patients with hyperphagia].

Research into dementia has tended to concentrate on memory loss and other cognitive impairment, but attention has recently turned to the associated psychiatric symptoms and behavioral abnormalities. Among them, increases in the amount eaten or hyperphagia are not uncommon in dementia. This problem is of clinical importance since it not only jeopardizes patient's health, but also is a cause of caregiver burden. The aim of this study was to assess the prevalence of hyperphagia in dementia. Additionally, possible mechanisms underlying this problem were reviewed and related to the demographic data, cognitive function test, radiological findings and other psychiatric symptoms. Out of a sample of 91 demented inpatients, hyperphagia was present in 30.8%. Hyperphagia was significantly associated with delusion, misidentification, aggressive behavior, hoarding behavior and pica phenomena. But these patients did not show difference in cognitive function, radiological abnormalities, repetitive behavior and depressed mood when compared with other demented patients. The possible etiologies were discussed, including physiological and psychological factors. Hyperphagia is a complex phenomenon, better understanding of the underlying pathogenesis may highlight specific pharmacological or behavioral methods for the management this troublesome behavior.

Aged↗

PubMed1996

Sex determination by discriminant function analysis of lateral radiographic cephalometry.

The present work is an attempt to develop a new method to determine sex from the skull with lateral radiographic cephalometry and discriminant function analysis. The superciliary ridges, frontal sinuses, external occipital protuberance, and mastoid processes were adopted as objects of lateral radiographic cephalometric measurements. With discriminant functions created from 18 established cephalometric variables, a total of 100 cases were classified into two sexual groups with 100% accuracy in a random sample of Taiwanese adults. Therefore, we may obtain a much greater reliability of sex determination from skulls according to this newly developed technique.

Adult↗

PubMed1996

Psychotic symptoms in psychiatric inpatients with dementia of the Alzheimer and vascular types.

BACKGROUND: Demented patients often manifest psychotic symptoms including delusion, hallucination and misidentification. This report attempts to describe the frequencies and characteristics of such symptoms in psychiatric inpatients with dementia, and to identify the characteristics of dementia with and without psychotic symptoms. METHODS: The study included 78 demented patients who were consecutively admitted to the psychiatric ward. Their psychotic symptoms were obtained from semistructured interview and the assessment using BEHAVE AD. Delusion and hallucination were rated as "present" if the descriptions were consistent with the definition of Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). Misidentification was defined individually. RESULTS: There were 54 patients with DAT and 24 patients with VD. The frequency of psychotic symptoms in DAT and VD was 71.8%. The frequency of delusion in DAT and VD was 59.0%, misidentification, 33.3% and hallucination, 25.6%. Demented patients with psychotic symptoms were older (p = 0.037) than those without psychotic symptoms. CONCLUSIONS: Psychotic symptoms are common in psychiatric inpatients with DAT and VD, the most common being delusional. Delusion of theft is the most common one. Demented patients with psychotic symptoms were older than those without.

Aged↗

PubMed1996

Growth characteristics of normal and dystrophic myoblasts in primary myoblast cultures.

This study employed immunocytochemistry and toluidine blue counterstaining to compare different procedures utilized in primary myoblast cultures, from which an optimal culture model for normal myoblasts could be derived. The growth characteristics of normal and dystrophic myoblasts were also investigated by means of this model. Results indicate that the requirements for an ideal myoblast culture should include a combined enzyme of 0.25% trypsin and 0.2% collagenase (type IV) (1:1), a preplating time of approximately 15-20 minutes, and a seeding density of 1 x 10(5) cells/ml. Furthermore, the mouse samples should be newborn mice. A better proliferative capacity of myoblasts was noted in an incubator with 10% CO2 coupled with Dulbecco's MEM plus 15% fetal calf serum. With regard to the growth characteristics of normal and dystrophic myoblasts, the doubling time of normal myoblasts was shorter than that of dystrophic myoblasts. In terms of the fusion percentage of myoblasts, dystrophic myoblasts tended to fuse earlier than normal ones, especially after 5 days in culture. The findings of this study are valuable in understanding the myogenesis of myoblasts under different culture conditions. The establishment of requirements for good growth of myoblast cultures will facilitate myoblast transfer therapy. Finally, the growth characteristics of normal and dystrophic myoblasts as well as variances in the proliferation and differentiation of these two types of cells are clarified.

Aging↗

PubMed1995

The temporal relationship between the severity of hydroureter and the dynamic changes of obstructed ureters in a rat model.

OBJECTIVE: To investigate dynamic changes in the obstructed rat ureter and to evaluate the usefulness of the rat model in the study of obstructive uropathy. MATERIALS AND METHODS: Unilateral ligation of the ureter was performed in 26 rats. After ureteric ligation, four to seven rats were killed and examined after 1, 3, 7, 10, and 14 days. The severity of hydroureter and hydronephrosis was assessed by pyelography and the hydroureter-hydronephrosis index. The middle portion of the ureter was prepared for light and electron microscopic observation. Five rats which received a sham operation were also examined as controls. RESULTS: The severity of hydroureter and hydronephrosis in the ligated ureters progressively increased during the period of obstruction (P < 0.005) and reached a maximum 10-14 days after ligation. Hypertrophy of the smooth muscle layer developed on the third day after ligation and proliferation of submucosal connective tissue occurred on the 10th day after ligation. The changes in smooth muscle and connective tissue layers also progressed consistently during ureteric obstruction (P < 0.001 and < 0.005, respectively). The number and size of granular endoplasmic reticulum and Golgi apparatus in the smooth muscle cells increased after ureteric ligation and then caveolae exocytosis developed. Deposition of collagen fibres between muscle cells became apparent later. CONCLUSION: The rat model of hydrouropathy demonstrated a clear temporal relationship between the severity of hydroureter and the dynamic changes in the obstructed ureter and could be used as a conventional method for the study of obstructive ureter.

Animals↗

PubMed1995

Use of rubella virus E1 fusion proteins for detection of rubella virus antibodies.

Two glutathione S-transferase fusion proteins containing 44 (p1503) and 75 (p1509) amino acid residues of the rubella virus E1 glycoprotein were expressed in Escherichia coli with the aim of producing a recombinant rubella virus antigen for use in serological assays. p1503 contained three neutralizing and hemagglutinating epitopes (G. M. Terry, L. M. Ho-Terry, P. Londesborough, and K. R. Rees, Arch. Virol. 98:189-197, 1988); p1509 contained the putative neutralization domain described by Mitchell et al. (L. A. Mitchell, T. Zhang, M. Ho, D. Decarie, A. Tingle, M. Zrein, and M. Lacroix, J. Clin. Microbiol. 30:1841-1847, 1992) in addition to the three epitopes present in p1503. Both fusion proteins were soluble and affinity purified on glutathione-Sepharose 4B. In Western blots (immunoblots), p1503 and p1509 reacted with human sera containing rubella virus-specific immunoglobulin G. When used as antigens in indirect enzyme immunoassays to detect rubella virus-specific immunoglobulin G, p1503 correctly identified the rubella virus antibody status of 43 (76.8%) and p1509 correctly identified that of 48 (85.7%) of 56 serum samples received for routine rubella virus antibody screening. The results obtained with p1509 compare well with those obtained with a latex agglutination assay.

Antibodies, Viral↗

PubMed1995

Primary culture of mouse myoblasts.

The literature has revealed variations in the protocols for myoblast cultures, and little information is available on myoblast and fibroblast proliferation. Therefore, the purposes of this study were to establish a prudent protocol for myoblast cultures by comparing a variety of culturing procedures used in previous research and to quantitate myoblast proliferation and fusion under different culture conditions. In addition, the growth status of myoblasts and fibroblasts was investigated. Results indicate that the requirements for an ideal myoblast culture should include a combined enzyme of 0.25% trypsin and 0.2% collagenase type IV (1:1), a preplating time of approximately 15-20 minutes, and a seeding density at 1 x 10(5) cells/ml. Furthermore, the mouse sample should be those of newborns. A better proliferative capacity of myoblasts was noted in an incubator of 10% CO2, coupled with Dulbecco's MEM plus 15% fetal calf serum. The doubling times of myoblasts were shorter than those of fibroblasts, and myoblast number reached its highest at 4 and 5 days. The findings of this study are valuable in understanding the growth status of myoblasts and fibroblasts in primary cultures. Moreover, the establishment of requirements for a good growth of myoblast cultures will facilitate myoblast transfer therapy.

Animals↗

PubMed1995

[Clinical significance of dystrophin positive fibers in Duchenne muscular dystrophy].

Dystrophin is a protein product of the Xp 21 gene which is defective in patients with Duchenne muscular dystrophy (DMD). In immunohistochemical staining of dystrophin, the majority of DMD muscle fibers show negative staining. Nevertheless, biopsy specimens from DMD patients labeled with many different antibodies may show a small number of fibers which are clearly dystrophin positive. This very small percentage of dystrophin-positive fibers (DPF) probably represents somatic reversion, suppression of the DMD gene mutation or alternating splicing of dystrophin mRNA. To determine the significance of isolated DPF in muscle specimens of DMD patients, we examined 30 DMD muscle specimens, aged 4 years to 16 years, by the use of monoclonal antibody against the C-terminal region of dystrophin. Additionally, muscle specimens from 2 normal human controls and 2 mice with X-linked muscular dystrophy were used for positive and negative controls, respectively. Muscle specimens from DMD patients and mdx mice showed almost totally negative dystrophin staining in most of their muscle fibers, but in 20 patients, three was a trace of isolated DPF ranging from 0.06% to 0.77%. DMD patients with no isolated DPF seemed to have higher functional disability. In the whole group of 30 patients, a significant negative correlation was found between the abundance of DPF and clinical functional grading (r = -0.85, p < 0.0001, based on linear regression). It is suggested that even the very low concentrations of dystrophin found in DMD patients may have a favorable functional significance.

Adolescent↗

PubMed1995

Morphological remodeling of the motor end plate in rat soleus muscle after limb immobilization by casting.

The effects of muscular inactivity on motor end plate(MEP) structures of the rat soleus muscle were studied qualitatively and quantitatively. Eight adult rats were divided into two equal groups. One group had their right hind limbs immobilized by application of plaster casts. After 14 days in the casts, the soleus muscles of all the animals were removed. Three groups of MEPs were analyzed to compare their structural characteristics: the immobilized group (the MEPs of the casted soleus muscles), the contralateral group (the MEPs of soleus muscles which were in legs contralateral to the casted legs), and the control group (the MEPs of normal soleus). The MEPs were examined in a teased preparation of soleus muscles stained by silver-impregnation. The architecture of the MEPs was measured by an "AMS VIDS III Image Computerized System" which was mounted with a light microscope for morphological analysis. The measured parameters were the structural elements of MEPs. The results of the present study showed that: MEPs of the immobilized group exhibited more complex and highly branches structures than the other two groups. The total number of branches and the length of the terminal perimeter in the immobilized group increased significantly. Concomitantly, the amount of swollen terminals of this group were obviously larger than in the other two groups. The results demonstrated that the muscular inactivity of the casted limbs produced denervation-like changes at branches of nerve terminals. These changes were the result of altered muscular function, and led to structural remodeling of MEPs of the muscles.

Animals↗

PubMed1995

[Characteristics of dementia patients with aggressive behaviors].

Aggressive behaviors are found in dementia patients and pose major problems for their caregivers and may be amenable to treatment. The present study aims to determine the frequency of aggressive behaviors in dementia patients and to test whether there is a relationship with the psychiatric symptoms. Ninety-one dementia patients from a geriatric psychiatry unit were surveyed for the aggressive behaviors and psychiatric symptoms by semi-structured interview with the patients and their caregivers. Major findings included that 53.8% of these patients had aggressive behaviors; these patients were older and had later onset of dementia; the presence of hallucination, misidentification and wandering were significant predictors of physical aggression; the association of aggressive behaviors with the cognitive test and delusion was not significant. These observations suggest that dementia patients have a high prevalence rate of aggressive behaviors that warrants the prevention and intervention. Hallucination, misidentification and wandering are risk factors for physical aggression and potentially trestable. Further research is needed to identify the cause and the management of aggressive behaviors in dementia patients.

Aged↗

PubMed1994

Comparative study of growth of Chinese infants: Hong Kong versus Guangzhou.

The growth of 174 infants from Hong Kong and 221 infants from Guangzhou from birth to 2 years were compared. Ethnic origins, parental size, and birth weights were similar. Common illnesses in the two groups were upper respiratory tract infection and diarrhoea. The early infant feeding practices were different, with more breastfeeding and earlier introduction of solids in Guangzhou. Compared to those of Hong Kong, Guangzhou babies had lower weight for length in the first year of life. Within the Guangzhou group, babies totally breastfed for the first 2-4 months were heavier than those given rice cereals as supplement and they had less diarrhoea in the first 6 months. Hong Kong infants suffered more diarrhoea than the Guangzhou group. It was concluded that breastfeeding should be promoted and supported in these two cities.

Adult↗

PubMed1993

Purification and characterization of reversible sperm motility inhibitors from porcine seminal plasma.

Two sperm motility inhibitors (SMI1 and SMI2) were purified from porcine seminal plasma with high performance liquid chromatography (HPLC). Their molecular weights are about 15,000 as estimated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Both of them decreased the percentage of motile spermatozoa in a dose-dependent manner. The inhibitory effect can be abolished by addition of the porcine follicular fluid. Both SMI1 and SMI2 have similar amino acid composition, suggesting that they may be structurally related. They also have inhibitory effect on chymotrypsin.

Amino Acid Sequence↗

PubMed1993

Effects of long-term estradiol exposure on the hypothalamic neuron number.

Neuron density, volume of the area and total neuron number were measured in the medial preoptic area, anterior hypothalamic area and arcuate nucleus of the hypothalamus of young (6-month-old), middle age (14-month-old) and old (22-month-old) male and female rats. Intact male rats did not show neuron loss even in old age, while intact female rats manifested neuron loss in the medial preoptic area, anterior hypothalamic area and arcuate nucleus in old age. Long-term administration of estradiol benzoate to castrated male rats induced neuron loss in the anterior hypothalamic area and arcuate nucleus of the middle age group and in all three areas of the old age group. However, long-term ovariectomy could not prevent neuron loss in these hypothalamic areas in old age. The results suggested that estradiol can have a cumulative impact on the degree of neuron damage and simulate female-type age-related neuron loss in male rats and that there may be the possibility of an intrinsic aging process inducing neuron loss in female rats.

Animals↗

PubMed1993

The gastro-intestinal absorption of griseofulvin can be enhanced by encapsulation into liposomes.

Liposomes are microscopic structures consisting of one or more lipid bilayers enclosing a definite aqueous space. They are widely used as a drug carrier and for the delivery of drugs through membranes. Drugs can be encapsulated into the inner water phase or lipidic wall, depending on their own hydro- or lipophilicity. The characteristics of the vesicles is fusion with cells and natural endocytosis uptake. We applied the properties of liposomes to overcome the poor gastro-intestinal (GI) absorption of griseofulvin and compared results with the traditional dosage form. In this experiment, the maximum plasma concentration obtained from griseofulvin liposomes was about 2.6 times than that from griseofulvin suspension. We used the lipids to prepare liposomes that consisted of phosphatidycholine, cholesterol, and dicetylphosphate in the molar ratio, 1:1.6:0.2, which is similar to the membrane composition of red blood cells. We examined some factors affecting the encapsulation ratin (E.R.%) and physicochemical properties of liposomes. When the lipid-to-griseofulvin weight ratio approached 38:1, the encapsulation ratio reached 94%. The different lipid/aqueous ratio (19/1 48/1 96/1) appeared to have little effect on E.R. value. The stability of griseofulvin liposomes in terms of leakage of griseofulvin was negligible over a period of 18 days at 4 degrees C. The sedimentation of vesicles bearing negative charges exhibited the best flocculation state. The plasma level-time profile of griseofulvin obtained from ingestion of liposomal dosage form showed itself to be significantly higher (P<0.01) Cmax, AUC, Ka, and t1/2 than that from suspension.

Absorption↗