Biomedical subjects

T Y Lin

Publications and source records attributed to T Y Lin.

At least 109 records · Page 6Linked to original sources

PubMed1998

Schizophrenia: conceptual change in modern psychiatry.

Schizophrenia is perhaps the most devastating mental illness that psychiatrists must treat. Its chronic course with deteriorating consequences has been the focus of study throughout this century. This paper reviews the concept of schizophrenia, from fundamental Kraepelinian theory of 'dementia praecox' to biological correlates and explanation. Its causes, however, remain obscure and there were no appreciable changes in its treatment modality. A 'bio-psycho-social' model of care is emphasized, aiming at the prevention of deterioration of symptoms, functional impairment, disability and social handicap.

Humans↗

PubMed1997

Hepatitis C and G virus infections in polytransfused children.

UNLABELLED: The prevalence of hepatitis C virus (HCV) and a newly identified hepatitis G virus (HGV) and their clinical significance were studied in 42 polytransfused Taiwanese children. Serological assays for antibodies against HCV (anti-HCV) and polymerase chain reaction for serum HCV ribonucleic acid (RNA) and HGV RNA were performed. The prevalence of anti-HCV and HGV RNA was 17% and 14%, respectively in 42 polytransfused children. Anti-HCV seropositives had a significantly higher mean age, peak serum transaminase level, and longer transfusion duration than seronegatives, while children with HGV infection usually had no or only mild hepatitis activities. The prevalence of anti-HCV dropped sharply after implementation of anti-HCV screening, however the prevalence of HGV viraemia remained unchanged. CONCLUSIONS: HGV infection is not uncommon in polytransfused Taiwanese children and the virus does not cause significant hepatitis compared to HCV infection. Current blood donor screening for anti-HCV can effectively protect polytransfused children from HCV infection but the impact of additional screening for HGV markers awaits further studies.

Adolescent↗

PubMed1997

Specific immune response in adult medical personnel immunized with acellular pertussis vaccine with special emphasis on T helper cell response.

Recent epidemiologic data have indicated that adults are the most important reservoir that transmit pertussis to children. However, conventional whole cell pertussis vaccine is contraindicated in adults and children over 7 years of age because of the unacceptably high rate of adverse reactions. The aim of this study is to evaluate the specific cellular immune responses and adverse reactions to a less reactogenic acellular pertussis vaccine in adult volunteers. Eighty healthy medical personnel in Chang Gung Children's Hospital were enrolled. Volunteers in each group received: (1) Td + full strength acellular pertussis vaccine (PT, 1 microgram/0.5 ml; FHA, 4 micrograms/0.5 ml); (2) Td + half strength acellular pertussis vaccine; (3) Td alone. Lymphocyte phenotypic analysis, antigen-specific antibody titers, antigen-specific proliferative response and cytokine levels were evaluated before and 1 month after vaccination. Our data revealed: (1) the adverse reactions were minimal; (2) phenotypic analysis showed no non-specific activation of helper T or memory T cell after vaccination; (3) both PT and FHA-specific antibody titers increased significantly after vaccination, (4) PT antigens had a mitogenic effect on cord blood mononuclear cells and peripheral blood mononuclear cells of the adult volunteers; (5) FHA-specific T cell proliferative responses significantly increased after vaccination; (6) the cytokine production pattern showed predominant activation of Th 1 cells as reflected in increased production of gamma-IFN after vaccination. Acellular pertussis vaccine can effectively induce both humoral and cellular immune response in adults.

Adhesins, Bacterial↗

PubMed1997

Identification of febrile neonates unlikely to have bacterial infections.

OBJECTIVE: A prospective study was undertaken to evaluate the usefulness of low risk criteria for identifying febrile neonates unlikely to have bacterial infections, particularly bacteremia and meningitis. Using these criteria we wished to check whether these low risk neonates can be safely managed as inpatients under close observation but without receiving empiric antibiotic therapy. STUDY DESIGN: We conducted a prospective study of 250 consecutive infants 28 days of age or less (range, 4 to 28 days) who had rectal temperatures of at least 38 degrees C. After a complete history, physical examination and sepsis workup, the 131 febrile neonates with clinical and laboratory findings indicating low risk for bacterial infections were hospitalized, closely observed and not given antibiotics. The low risk criteria used to identify these neonates included well appearance; absence of physical signs of an ear, eye or soft tissue infection; a white blood cell count of 5000 to 15,000/mm3, a neutrophil band form count of < 1500/mm3, a spun urine specimen that had < 10 white blood cells per high power field on microscopy and a C-reactive protein value of < 20 mg/l. The remaining 119 febrile neonates who did not meet the low risk criteria were hospitalized and given empiric antibiotics pending culture results. RESULTS: The overall incidence of bacterial infections in the 250 febrile neonates was 16.4% (41 neonates) with bacteremia and/or meningitis occurring in 4.4% (11 neonates). Of the 131 low risk neonates only one (0.8%) had a bacterial infection (urinary tract infection) compared with 40 (33.6%) among the 119 who did not meet the criteria (P < 0.05). The negative predictive value of these criteria for excluding bacterial infections was 99.2% (95% confidence interval, 97.7% to 100%). For bacteremia and meningitis this figure became 100%. However, the positive predictive value and specificity of the criteria were too low to identify all febrile neonates with bacterial infections. Among the low risk group 58 (44.3%) were reclassified on the second or third hospital day, because of continued fever (35), poor activity (14) and white blood cell count > 15000/mm3 on a repeat blood test (9). They were given antibiotics, but only 1 had a urinary tract infection. This patient was then treated with a 7-day course of antibiotics. All low risk neonates recovered uneventfully with no relapses observed during their hospital stay or at the time of minimum 1-week outpatient follow-up visits. CONCLUSION: By the low risk criteria a substantial number of febrile neonates at low risk for bacterial infections can be identified and managed safely as inpatients without antibiotic therapy.

Anti-Bacterial Agents↗

PubMed1997

Oral acyclovir prophylaxis of varicella after intimate contact.

OBJECTIVES: Whether oral acyclovir (ACV) given in late incubation can prevent clinical varicella or not. MATERIALS AND METHODS: Twenty-seven healthy infants and children susceptible to varicella received oral ACV (40 mg/kg daily in four divided doses) for 5 days, starting 9 or 11 days after exposure from the index case in the family (2 in the classroom). The clinical features were compared with 13 control children who did not receive ACV. Enzyme-linked immunoassay was used to detect varicella-zoster virus (VZV) antibody and, in follow-up immunologic studies, lymphocyte proliferative response was added. In some cases, blood culture and polymerase chain reaction with Southern hybridization were used for detection of viremia. RESULTS: Among the 27 children in the treatment group, two (7.4%) developed the disease and seroconversion was observed in 17 subjects (63%). Follow-up immunologic studies in 12 of these 17 seroconverted subjects 30 months later showed persistent cellular and/or humoral immunity to VZV. Only one subject, bled 11 days after exposure, had positive VZV DNA and blood culture for VZV. On the other hand 10 of 13 (77%) control subjects developed clinical varicella. CONCLUSIONS: Oral ACV administration to healthy susceptible subjects at the beginning of secondary viremia in the late incubation period (9 days after exposure) can effectively prevent or modify clinical varicella.

Acyclovir↗

PubMed1997

Tuberculosis of the long bone in children.

From 1985 to 1994, there were 24 cases of long bone solitary tuberculosis. They were 18 boys and 6 girls with an average age of 18 months. All of the patients were treated by open biopsy and curettage and antituberculosis therapy (isoniazid and rifampin) for 6 months. Two patients had incomplete administration of the drug therapy. The lesions were in the metaphysis. Epiphyseal involvement was not significant. The tuberculin skin test was negative in 3 children and the culture was negative in 17 cases. After 2 years and 8 months' followup, there was radiographic evidence of good bone remodeling. Although there uncommonly is not a delay in diagnosis of skeletal tuberculosis despite prolonged symptoms, diagnostic biopsy with curettage of the lesion is indicated for isolated lesions, especially when the diagnosis is in doubt. It is significant that surgical debridement can shorten the duration of antituberculosis therapy and lead to improved results.

Antitubercular Agents↗

PubMed1997

Microbiologic and histologic diagnosis of histoplasmosis in Taiwan.

Histoplasmosis is one of the most common opportunistic fungal infections in immunocompromised patients in endemic areas. We report the first two microbiologically documented cases of histoplasmosis in Taiwan. The first patient, with acquired immunodeficiency syndrome and a depleted CD4+ lymphocyte count, presented with a history of prolonged fever, papular skin rashes, pancytopenia and elevation of liver enzymes. He was diagnosed and treated initially for systemic toxoplasmosis, but the microbiologic and pathologic findings of the autopsied specimens disclosed disseminated infection caused by Histoplasma capsulatum. The second patient, an elderly man receiving corticosteroids for adrenal insufficiency, manifested with laryngeal histoplasmosis and was successfully treated with ketoconazole.

AIDS-Related Opportunistic Infections↗

PubMed1997

Unusual manifestations in children with Kawasaki disease.

Between January 1983 and December 1992, the medical records of 187 patients (116 boys and 71 girls) with Kawasaki disease (KD) who were admitted to the hospital in the acute phase were retrospectively reviewed. Of these, 175 patients (93.6%) were under 4 years of age. Among the six principal symptoms of KD, the incidence of cervical lymphadenopathy (41.2%) was relatively low. Additionally, we found some unusual features including intussusception in a 4-month-old female, transient thrombocytopenia in seven children (3.7%) and isolated azotemia in five. KD is a systemic disease of unknown etiology. The diverse associated features make KD puzzling and difficult to diagnose. In caring for children with KD, physicians should be alert to the principal symptoms as well as the unusual associated manifestations.

Child↗

PubMed1997

A pilot study of seven days of ceftriaxone therapy for children with Salmonella enterocolitis.

BACKGROUND: The most effective therapy for non-typhoid Salmonella enterocolitis is still unknown. Traditionally, unless extraintestinal complications are present, antimicrobial drugs are not recommended, since earlier trials have shown that antibiotics such as ampicillin, chloramphenicol, or co-trimoxazole, do not shorten the duration of diarrhea and may even prolong convalescent fecal carriage of the bacteria. However, the recently-developed third generation cephalosporin ceftriaxone has been used successfully in the treatment of typhoid fever and other systemic salmonellosis. A controlled, pilot study was therefore undertaken to evaluate the efficacy of intravenous ceftriaxone in the treatment of children with non-typhoid Salmonella enterocolitis. METHODS: Fifteen children with Salmonella enterocolitis and bacteremia who were eligible for antibiotic therapy were given ceftriaxone intravenously for 7 days and 15 children with enterocolitis but without bacteremia who were admitted for supportive treatment during the study period were selected as the control group. Available stool samples collected on days, 7, 14, and 30 after the completion of the drug therapy were checked for the presence of the bacteria using polymerase chain reaction (PCR) and culture methods. RESULTS: The result showed that the duration of diarrhea was not significantly affected by ceftriaxone treatment. However, the difference in the rate of clearance of Salmonella from stools, as defined by negative stool cultures and PCR, was statistically significant between the two groups on posttreatment days 7 and 14. Only one patient given ceftriaxone was shown to have recrudescence of the bacteria in feces on day 14. One month after therapy, PCR was positive in two of the ten cases tested and one of these two experienced a relapse of diarrhea, whereas bacterial carriage was maintained in 63% of the control patients. CONCLUSION: A prompt eradication of Salmonella in feces was observed in most of the patients treated with ceftriaxone in this study. If further studies confirm the efficacy of this therapy and the risk of inducing drug resistance is minimal, the epidemiologic problem created by convalescent fecal bacterial carriage may justify a short-course of ceftriaxone therapy for children with Salmonella enterocolitis.

Ceftriaxone↗

PubMed1997

Isolation and expression of a porcine lactoferrin gene.

OBJECTIVE: To elucidate the spatial and temporal expression of a porcine lactoferrin (LTF) gene. ANIMALS: 4 female and 4 male Large White pigs. PROCEDURES: We examined LTF expression in various organs excised from the pigs, using northern blot hybridization with a porcine LTF cDNA probe. Antibodies against porcine LTF were raised in rabbits and were used along with immunohistochemical staining to localize the LTF protein. RESULTS: High amounts of porcine LTF mRNA were detected in the secreting mammary gland and epididymis. This distribution is consistent with that of porcine LTF examined by immunohistochemistry. In female pigs, porcine LTF mRNA concentration increased remarkably in the ductal cells of the lactating mammary gland then significantly decreased at day 21 after parturition. Furthermore, specific staining for LTF was observed in the epithelial cells of the gastrointestinal tract of female pigs, but not in the uterus, ovaries, spleen, kidneys, pancreas, muscles, heart, brain, lungs, or liver of postpartum female pigs, or in the testes of male pigs. CONCLUSIONS: Gene expression of porcine LTF is closely related to lactation in the mammary gland. Distribution of LTF in the epididymis suggests that LTF may have a regulatory role in development of the reproductive tract of male pigs.

Animals↗

PubMed1997

Salmonella typhimurium brain abscess in a six-month-old infant: a case report and review of the literature.

We report the case of a six-month-old male infant with brain abscess caused by Salmonella typhimurium. Upon admission, he was suffering from fever, diarrhea, drowsiness and convulsion. Salmonella meningitis was identified by CSF examination. Following failure of antibiotic therapy to control his fever, brain computerized tomography (CT) was ordered 5 days later and revealed a brain abscess. He received surgical excision of the abscess and recovered completely after receiving ceftriaxone therapy for 8 weeks. The case of our patient, together with 11 cases of Salmonella brain abscess from the English literature are reviewed. There was a male preponderance among these patients (male: female = 2.67 : 1) and the majority were less than one year old. Salmonella typhimurium, typhi, and enteritidis occurred most frequently. Fever, seizure, signs and symptoms of increased intracranial pressure and change in mental status were the most common clinical features. Purulent meningitis was a major predisposing factor. Successful treatment was associated with early identification, prompt surgical intervention, high dose, long-term antibiotic therapy, and close follow-up for possible recurrence and to determine the presence of neurological sequelae.

Anti-Bacterial Agents↗

PubMed1997

Fatal Haemophilus influenzae pneumonia: two cases report.

Haemophilus influenzae is a common cause of acute childhood pneumonia. Most Haemophilus pneumonia generally follow a benign course with occasional complications of pleural effusion, pneumothorax or pneumatocele. Deaths following invasive Haemophilus pneumonia have rarely been reported in children older than 3 years of age. We report 2 deaths in children presenting with fulminant pneumonia, complicated by sepsis and adult respiratory distress syndrome despite vigorous antibiotic therapy and full resuscitative measures.

Child, Preschool↗

PubMed1997

The arc index in evaluation of Class III malocclusion.

Lateral cephalometric radiographs were obtained for 46 individuals (18 men and 28 women) aged 20 to 30 years. The sample consisted of Taiwanese with Class III malocclusions and prognathic facial profiles. A modification of the Sassouni arch analysis was used to evaluate this group. All parameters were compared with the norms for adult Taiwanese. The facial pattern of the Class III group was similar to that reported in other studies. The maxilla was in a retrusive position; the lengths of the maxilla and the mandible were significantly different from those in the normal group; the mandibular central incisor was retroinclined; and the total gonial angle, upper gonial angle, and lower gonial angle in the Class III group were significantly different from those angles in the normal group in both sexes. The arc index represented the maxillomandibular positional relationship. There was a statistically significant difference between the mean arc indexes of the Class III and the normal groups. The results indicated that the more negative the arc index, the greater the Class III tendency.

Adult↗

PubMed1996

The structure and expression of an hsc70 gene from Lycopersicon esculentum.

A tomato hsc70 genomic clone (Lehsc70-3; Lycopersicon esculentum heat-shock cognate 70-3) was obtained by screening a genomic library with the tomato Lehsc70-2 cDNA. Two restriction fragments of 2.6 and 5 kb, which compose the Lehsc70-3 gene, were subcloned into pBluescriptIIKS+ and analyzed. Transcript mapping reveals that the mature Lehsc70-3 mRNA contains a 122-nt 5' untranslated region (UTR), a coding region of 1956 nt corresponding to a polypeptide of 651 amino acids, an intron of 717 nt and a 3' UTR. Analysis of genomic DNA indicates that Lehsc70-3 is present as a low-copy-number gene. We note that the sequence upstream from the coding region of Lehsc70-3 shares common features with a number of hsc/hsp genes. High-temperature treatment (37 degrees C) caused a twofold increase in the level of the Lehsc70-3 mRNA. However, Lehsc70-3 has also been expressed at substantial levels in tomato vegetative tissues, suggesting a general function of this hsc70 gene in L. esculentum.

Amino Acid Sequence↗

PubMed1996

Hydrophobic interactions control zymogen activation in the trypsin family of serine proteases.

Trypsinogen is converted to trypsin by the removal of a peptide from the N terminus, which permits formation of a salt bridge between the new N-terminal Ile (residue 16) and Asp194. Formation of this salt bridge triggers a conformational change in the "activation domain" of trypsin, creating the S1 binding site and oxyanion hole. Thus, the activation of trypsinogen appears to represent an example of protein folding driven by electrostatic interactions. The following trypsin mutants have been constructed to explore this problem: Asp194Asn, Ile16Val, Ile16Ala, and Ile16Gly. The bovine pancreatic trypsin inhibitor (BPTI), benzamidine, and leupeptin affinities and activity and pH-rate profiles of these mutants have been measured. The changes in BPTI and benzamidine affinity measure destabilization of the activation domain. These experiments indicate that hydrophobic interactions of the Ile16 side chain provide 5 kcal/mol of stabilization energy to the activation domain while the salt bridge accounts for 3 kcal/mol. Thus, hydrophobic interactions provide the majority of stabilization energy for the trypsinogen to trypsin conversion. The pH-rate profiles of I16A and I16G are significantly different than the pH-rate profile of trypsin, further confirming that the activation domain has been destabilized. Moreover, these mutations decrease kcat/Km and leupeptin affinity in parallel with the decrease in stability of the activation domain. Acylation is selectively decreased, while substrate binding and deacylation are not affected. Together these observations indicate that the stability of protein structure is an important component of transition state stabilization in enzyme catalysis. These results also suggest that active zymogens can be created without providing a counterion for Asp194, and thus have important implications for the elucidation of the structural features which account for the zymogen activity of tissue plasminogen activator and urokinase.

Amino Acid Sequence↗

PubMed1996

On the role of surface tension in the stabilization of globular proteins.

The stabilization of proteins by a variety of co-solvents can be related to their property of increasing the surface tension of water. It is demonstrated that, during the thermal unfolding of proteins, this increase of the surface tension can be overcome by the increase in the temperature of the solution at the midpoint of the transition, Tm, and the weak binding of co-solvent molecules. Three such co-solvents were studied: trehalose, lysine hydrochloride (LysHCl), and arginine hydrochloride (ArgHCl). Trehalose and LysHCl increase the midpoint of Tm. The increase of the surface tension by addition of trehalose is completely compensated by its decrease due to the increase in Tm. However, for LysHCl, the increase of the surface tension by the co-solvent is partly reduced by its binding to the protein. For trehalose, preferential interaction measurements with RNaseA demonstrate that it is totally excluded from the protein. In contrast, LysHCl gives evidence of binding to RNaseA. ArgHCl also increases the surface tension of water. Nevertheless, Tm of RNaseA decreases on addition of ArgHCl to the solution. Preferential interaction measurements showed very small values of preferential hydration of the native protein, indicating extensive binding of ArgHCl to the protein. During unfolding, the amount of additional ArgHCl binding is sufficiently large to counteract the surface tension effects, and the protein is destabilized. Therefore, although surface tension appears to be a critical factor in the stabilization of proteins, its increase by co-solvent does not ensure increased stabilization. The binding of ligands can reduce significantly, or even overwhelm, its effects.

Animals↗

PubMed1996

Diagnostic value of C-reactive protein in children with perforated appendicitis.

UNLABELLED: The diagnostic value of serum C-reactive protein (CRP) levels in children with perforated appendicitis was prospectively studied in 78 consecutive patients with histologically confirmed appendicitis. The patients were divided into two groups: group A included 56 patients with perforated appendicitis and group B consisted of 22 patients with simple appendicitis. Serum CRP level and leucocyte count were assayed in all and abdominal ultrasonography was performed in 75. The mean age group A patient was significantly lower than that of group B patients (7.5 vs. 10.4 years, P < 0.001). Group A patients had a significantly higher mean serum CRP levels than group B patients (92 vs. 31 mg/l, P < 0.001), while the mean leucocyte count was comparable in the two groups. Of 75 examined patients, 73 (97%) had a pre-operative sonographic diagnosis of appendicitis. CONCLUSION: Perforation is a common complication in children with appendicitis, especially in those of young age and with prolonged pain duration. Greatly increased serum CRP levels (> or = 50 mg/l) and abdominal ultrasonography are important diagnostic aids in such patients.

Adolescent↗

PubMed1996

Responses to primary and a booster dose of acellular, component, and whole-cell pertussis vaccines initiated at 2 months of age.

A second generation acellular pertussis vaccine (component pertussis vaccine) containing purified pertussis toxin (PT) and filamentous hemagglutinin (FHA) was tested for its immunogenicity and safety in 2-month-old infants in comparison with first-generation acellular and whole-cell pertussis vaccines. At the ages of 2, 4, 6, and 18 months, respectively, 350 subjects were inoculated one dose of pertussis vaccine, which was combined with diphtheria and tetanus toxoids. Both acellular and component vaccines elicited significantly much fewer local and systemic reactions than whole-cell vaccine did. Besides, although not reaching statistical significance, the component vaccine was less reactogenic than the acellular vaccine. After each dose of the primary immunization, antibodies against PT and FHA were much higher in acellular and component pertussis vaccinees than in whole-cell vaccinees. However, at 18 months of age, just before the booster dose, both anti-PT and anti-FHA declined very close to, or even lower than, the prevaccination levels in all three groups and then responded rapidly to a booster dose to attain high levels. The booster responses were also significantly higher (P < 0.01) in acellular and component groups than in whole-cell group. Component and acellular vaccines induced similar levels of anti-FHA but the former induced higher anti-PT than the latter (P < 0.01). Our results indicate that both in primary immunization and as a booster, acellular and component pertussis vaccines are much more immunogenic for PT and FHA and much less reactogenic than whole-cell vaccine. However, the persistence of anti-PT and anti-FHA was not as good as one can expect from other protein antigens without giving a booster dose. A long-term follow-up of the vaccinees has been underway to understand the persistence of these antibodies after the first booster.

Antibodies, Bacterial↗