Valpha gene replacement in a TCRalpha knock-in mouse

Using a TCRalpha chain knock-in mouse, we demonstrate that V-gene replacement can operate in the T cell receptor alpha locus. Functional TCRalpha chain transcripts generated by Valpha-gene replacement at the site of the Valpha-embedded heptamer were identified in splenic T cells. This finding shows that Valpha-gene replacement can likely be used to shape the peripheral T cell repertoire. The conservation of the embedded heptamer in most Valpha segments adds support to the notion that V-gene replacement is a mechanism maintained to diversify the immune system and that argues that it is common to B and T cells.

The role of flow-independent viscoelasticity in the biphasic tensile and compressive responses of articular cartilage

A long-standing challenge in the biomechanics of connective tissues (e.g., articular cartilage, ligament, tendon) has been the reported disparities between their tensile and compressive properties. In general, the intrinsic tensile properties of the solid matrices of these tissues are dictated by the collagen content and microstructural architecture, and the intrinsic compressive properties are dictated by their proteoglycan content and molecular organization as well as water content. These distinct materials give rise to a pronounced and experimentally well-documented nonlinear tension-compression stress-strain responses, as well as biphasic or intrinsic extracellular matrix viscoelastic responses. While many constitutive models of articular cartilage have captured one or more of these experimental responses, no single constitutive law has successfully described the uniaxial tensile and compressive responses of cartilage within the same framework. The objective of this study was to combine two previously proposed extensions of the biphasic theory of Mow et al. [1980, ASME J. Biomech. Eng., 102, pp. 73-84] to incorporate tension-compression nonlinearity as well as intrinsic viscoelasticity of the solid matrix of cartilage. The biphasic-conewise linear elastic model proposed by Soltz and Ateshian [2000, ASME J. Biomech. Eng., 122, pp. 576-586] and based on the bimodular stress-strain constitutive law introduced by Curnier et al. [1995, J. Elasticity, 37, pp. 1-38], as well as the biphasic poroviscoelastic model of Mak [1986, ASME J. Biomech. Eng., 108, pp. 123-130], which employs the quasi-linear viscoelastic model of Fung [1981, Biomechanics: Mechanical Properties of Living Tissues, Springer-Verlag, New York], were combined in a single model to analyze the response of cartilage to standard testing configurations. Results were compared to experimental data from the literature and it was found that a simultaneous prediction of compression and tension experiments of articular cartilage, under stress-relaxation and dynamic loading, can be achieved when properly taking into account both flow-dependent and flow-independent viscoelasticity effects, as well as tension-compression nonlinearity.

Temperature-dependent helix-coil transition of an alanine based peptide

The helix-coil transition of a synthetic alpha-helical peptide (the D-Arg peptide), Ac-YGG(KAAAA)(3)-CO-D-Arg-CONH(2), was studied by static far-UV circular dichroism (CD) and time-resolved infrared spectroscopy coupled with the laser-induced temperature-jump technique for rapid relaxation initiation. Equilibrium thermal unfolding measurements of the D-Arg peptide monitored by CD spectroscopy reveal an apparent two-state helix-coil transition, with a thermal melting temperature around 10 degrees C. Time-resolved infrared (IR) measurements following a laser-induced temperature jump, however, reveal biphasic (or multiphasic) relaxation kinetics. The fast phase rises within the 20 ns response time of the detection system. The slow phase has a decay lifetime of approximately 140 ns at 300 K and exhibits monotonic temperature dependence with an apparent activation energy around 15.5 kcal/mol.

Microsized 2D protein arrays immobilized by micro-stamps and micro-wells for disease diagnosis and drug screening

A novel method of protein array immobilization, using micro stamps to pick up proteins from micro wells and deposit them on to a bio-absorption chip, has been developed. This method can potentially transfer several protein spots on to an organized array for applications such as disease diagnosis and drug screening by parallel biological or chemical processes. Fabrication of the micro stamp and the micro well arrays involves thick-photoresist lithography, bulk micromachining, and a molding process, whereas fabrication of the bio-absorption chip involves amino-modification by use of APTS (aminopropyItrimethoxysilane) and surface activation by use of BS3 (bis-sulfosuccinimidyl suberate). Successful transfer of protein on to the bio-absorption surface using the micro stamp-well array has been demonstrated. The size variation between different stamping spots has been shown to be less than 10%, and the APTS-BS3 surface has also been proved to bind the protein efficiently. Appreciable protein retention was achieved during 6-h washing, which shows the binding strength of the bio-absorption surface is sufficient for protein processing.

A study of apolipoproteins E and A-I in cutaneous amyloids

BACKGROUND

Apolipoprotein E (apoE) is present in a variety of biochemically different amyloid deposits, including Alzheimer's disease, systemic amyloidosis and primary cutaneous amyloidosis (PCA). Among the three closely related alleleic forms of apoE, the epsilon4 allele is linked to Alzheimer's disease. Apolipoprotein A-I (apoA-I), another apolipoprotein, is also found in senile plaques of Alzheimer's disease and in amyloid of aortic atherosclerotic plaques. Furthermore, apoA-I has recently been found to be associated with hereditary cutaneous and cardiac amyloidosis.

OBJECTIVES

To determine whether the apoE epsilon4 allele is associated with increased risk of PCA and whether apoE and apoA-I are present in PCA and common secondary cutaneous amyloidosis (SCA) (i.e. basal cell carcinoma, Bowen's disease and seborrhoeic keratosis).

METHODS

We examined the apoE genotype in 57 Chinese patients with PCA and 58 normal healthy control subjects of similar age. In addition, immunohistochemical staining was performed to determine the localization of apoE and apoA-I in skin tissues from 15 patients with SCA and 15 with PCA.

RESULTS

The frequency of the epsilon4 allele in the PCA group was not significantly higher than that in the control group (8.8% vs. 6.9%, P > 0.05). ApoE was present in amyloid deposits in both PCA and SCA, but apoA-I was not detected in these cutaneous amyloid deposits.

CONCLUSIONS

ApoE is also a component of amyloid deposits in SCA. Although the genetic susceptibility of certain apoE isoforms may not be a crucial factor in the development of PCA and, although apoA-I is not associated with amyloid deposits of PCA and SCA, the role of apolipoproteins in amyloidogenesis deserves further scrutiny.

Withering syndrome of the small abalone, Haliotis diversicolor supertexta, is caused by Vibrio parahaemolyticus and associated with thermal induction

The susceptibility of the small abalone Haliotis diversicolor supertexta to Vibrio parahaemolyticus 880915 strain and its extracellular products (ECP) at different temperatures was investigated. The strain was previously isolated from the haemolymph of the moribund small abalone with withering syndrome during an outbreak of mass mortality among the cultured animals in September 1999 in I-Lan, Taiwan. The bacterium and its ECP were lethal to the small abalone. Onset of the withering syndrome in the moribund or dead animals could be observed at 4-7 d post-bacterial challenge. The same bacterial strain could be isolated from the haemolymph of the moribund animals with or without the syndrome post-bacterial challenge. This syndrome could not be observed in the moribund or dead animals post-ECP challenge. The animals were more susceptible to the bacterium and ECP challenge at higher temperature (28 degrees C) indicating that the outbreak of the disease in warmer season is associated with thermal induction.

Retrospective comparison of the AJCC 5th edition classification for nasopharyngeal carcinoma with the AJCC 4th edition: an experience in Taiwan

OBJECTIVE

The aim of this study was to compare the new AJCC 5th edition classification system for nasopharyngeal carcinoma (NPC) with the AJCC 4th edition by re-evaluating the staging of patients treated in Taiwan.

METHODS

From 1992 through 1996, 117 NPC patients without distant metastasis were treated using complete courses of radiotherapy. All patients had complete CT examinations of the nasopharynx and neck. Each patient was re-staged according to the 5th edition of the AJCC classification system. Their overall survival (OS), loco-regional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS) and disease-free survival (DFS) were compared between the two staging systems, using the Kaplan-Meier method, log-rank test, Wilcoxon test and Cox proportional hazard model.

RESULTS

After a median follow-up of 58.3 months, the 5-year OS for stage I, II, III and IV was 88, 86, 61 and 48%, respectively, according to the new staging. A more even distribution of patients was noted among the patients classified according to the AJCC 5th edition than the 4th edition. The distribution of stages I, II, III and IV was 13.7, 37.6, 15.4 and 33.3%, respectively, using the new staging system, whereas it was 0.8, 14.5, 20.5 and 64.2%, respectively, using the old staging system. More statistically significant differences among 5th edition stages and T classifications than the 4th edition were also noted.

CONCLUSIONS

The 5th edition of the AJCC staging system appears to have a more even distribution of patients and more statistically significant differences in predicting prognosis than the 4th edition, mostly in stages and T classification.

Surgical treatment for Haglund's deformity

Haglund's deformity, or "pump bump" is a common cause of posterior heel pain, characterized clinically by a painful soft tissue swelling at the level of the Achilles tendon insertion. We reviewed 30 heels in 19 patients with failure of conservative treatment. Surgical management consisted of excision of the posterior calcaneal tuberosity and bursectomy through a medial longitudinal incision. The average follow-up period was 6 years (range, 3-10 years). Only 3 heels (10%) in 2 patients had persistent pain. Twenty-seven heels (90%) were cured after operation. However, 25 heels (83%) had residual pain for a half to two years after operation and became free of symptoms thereafter. We conclude surgical treatment of Haglund's deformity produces a predictably good result (90%) but requires a long time about a half to two years for full recovery.

Familial influence on age of onset among siblings with Huntington disease

In order to provide data relevant to a search for modifying genes for age of onset in Huntington disease, we examined the relationship between CAG number and age of onset in a total of 370 individuals from 165 siblingships, in two cohorts of siblings with Huntington disease: an American group of 144 individuals from 64 siblingships, and a Canadian population of 255 individuals from 113 siblingships. Using a logarithmic model to regress the age of onset on the number of CAG triplets, we found that CAG number alone accounted for 65%-71% of the variance in age of onset. The siblingship an individual belonged to accounted for 11%-19% of additional variance. This adds to the previous evidence that there are familial modifiers of the age of onset, independent of the CAG number. Such modifiers may consist of additional genes, which could be the target of a linkage study. A linkage study is feasible with the cooperation of a number of major centers and may be made more efficient by concentrating on sibling pairs that are highly discordant for age of onset.

Combined effects of two sulfonylurea herbicides on soil microbial biomass and N-mineralization

The interaction effect of two sulfonylurea herbicides, bensulfuron-methyl (B) and metsulfuron-methyl(M), were tested on microbial biomass C, N, N-mineralization and C/N ratio in a loamy sand soil. The herbicides were applied at various levels of: control (B0M0), 0.01 and 0.01 (B1M1), 0.01 and 0.1 (B1M2), and 0.01 and 1.0 (B1M3) microgram/g soil. Determinations of soil microbial biomass-C, N and N-mineralization contents were carried out at 1, 3, 5, 7, 10, 15, 25 and 45 days after herbicides application. The results showed that the soil microbial biomass-C (Cmic) and microbial biomass-N (Nmic) decreased consistently with the increasing rates of herbicides. The results further indicated that B1M1 and B1M2 caused a significant reduction in Cmic and Nmic within first 10 and 7 days of incubation, respectively, as compared with the control. These reductions in Cmic and Nmic were also significant (P = 0.05) with B1M3 application especially within first 15 days of incubation. A significant reduction in N-mineralization (N-min) was observed with high doses (B1M2, B1M3) of herbicides within first 5 days of incubation, while low rate (B1M1) failed to produce any significant effect. An increase in the soil microbial biomass C:N ratio was also noted.

Cross-resistance and combined cytotoxic effects of paclitaxel and cisplatin in bladder cancer cells

PURPOSE

We studied the cross-resistance and combined cytotoxic effects of cisplatin and paclitaxel in bladder cancer cells in vitro.

MATERIALS AND METHODS

The cytotoxicity of the 2 agents alone or in combination were studied in the bladder cancer cell line NTUB1 and the 2 sublines NTUB1/P, which is cisplatin resistant, and NTUB1/T, which is paclitaxel resistant, using the microculture tetrazolium assay. Schedule dependence of the 2-drug combination was assayed using 3 treatment schedules, including 1 concurrent and 2 sequential exposures.

RESULTS

The mean cisplatin concentration plus or minus standard error of the means inhibiting 50% of the growth of NTUB1, NTUB1/P and NTUB1/T was 1.9 +/- 0.19, 19.3 +/- 2.33 and 2.1 +/- 0.15 microM., respectively, and the mean paclitaxel concentration inhibiting 50% of the growth of the 3 cell lines was 30 +/- 3.9, 1,033 +/- 120 and 110 +/- 15 nM., respectively. NTUB1/P had strong cross-resistance to paclitaxel. In contrast, NTUB1/T was as sensitive as NTUB1 to cisplatin. On median effect analysis the combined effects of the 2 agents given concurrently were sub-additive in the low fraction affected range of 0.1 to 0.3 and additive in the median to high fraction affected range of 0.4 to 1.0 in the 3 cell lines. Combined cytotoxicity was more synergistic when paclitaxel was given 24 hours earlier than cisplatin. The effects were less synergistic when cisplatin was given before paclitaxel. This phenomenon was noted in sensitive and resistant cells.

CONCLUSIONS

In our bladder cancer cell model cisplatin resistant cells have strong cross-resistance to paclitaxel, whereas paclitaxel resistant cells are sensitive to cisplatin. The combined effects may be optimized by sequential use of the 2 agents, preferably paclitaxel given 24 hours before cisplatin. Our results have clinical implications for the treatment of bladder cancer.

Site-directed mutagenesis of the ionizable groups in the active site of Zymomonas mobilis pyruvate decarboxylase: effect on activity and pH dependence

Pyruvate decarboxylase (PDC, EC 4.1.1.1) is a thiamin diphosphate-dependent enzyme about which there is a large body of structural and functional information. The active site contains several absolutely conserved ionizable groups and all of these appear to be important, as judged by the fact that mutation diminishes or abolishes catalytic activity. Previously we have shown [Schenk, G., Leeper, F.J., England, R., Nixon, P.F. & Duggleby, R.G. (1997) Eur. J. Biochem. 248, 63-71] that the activity is pH-dependent due to changes in kcat/Km while kcat itself is unaffected by pH. The effect on kcat/Km is determined by a group with a pKa of 6.45; the identity of this group has not been determined, although H113 is a possible candidate. Here we mutate five crucial residues in the active site with ionizable side-chains (D27, E50, H113, H114 and E473) in turn, to residues that are nonionizable or should have a substantially altered pKa. Each protein was purified and characterized kinetically. Unexpectedly, the pH-dependence of kcat/Km is largely unaffected in all mutants, ruling out the possibility that any of these five residues is responsible for the observed pKa of 6.45. We conjecture that the kcat/Km profile reflects the protonation of an alcoholate anion intermediate of the catalytic cycle.

Proteolytic activation of ETK/Bmx tyrosine kinase by caspases

Etk/Bmx is a member of the Btk/Tec family of kinases, which are characterized by having a pleckstrin homology domain at the N terminus, in addition to the Src homology 3 (SH3), SH2, and the catalytic domains, shared with the Src family kinases. Etk, or Btk kinases in general, has been implicated in the regulation of apoptosis. To test whether Etk is the substrate for caspases during apoptosis, in vitro translated [(35)S]methionine-labeled Etk was incubated with different apoptotic extracts and recombinant caspases, respectively. Results showed that Etk was proteolyzed in all conditions tested with identical cleavage patterns. Caspase-mediated cleavage of Etk generated a C-terminal fragment, containing the complete SH2 and tyrosine kinase domains, but without intact pleckstrin homology and SH3 domains. This fragment has 4-fold higher kinase activity than that of the full-length Etk. Ectopic expression of the C-terminal fragment of Etk sensitized the PC3 prostate cancer cells to apoptosis in response to apoptosis-inducing stimuli. The finding, together with an earlier report that Etk is potentially antiapoptotic, suggests that Etk may serve as an apoptotic switch, depending on the forms of Etk existing inside the cells. To our knowledge, this is the first case where the activity of a tyrosine kinase is induced by caspase cleavage.

Utility of PCR assays for rapid diagnosis of BCG infection in children

We report Mycobacterium bovis BCG infection in two children vaccinated with BCG (Tokyo strain) on the first day of life. Their diagnoses were made by biopsy of skin lesions and pus from an anterior chest wall abscess, respectively, yielding a positive culture of mycobacteria fully susceptible to rifampicin, isoniazid and ethambutol, but resistant to pyrazinamide. M. bovis BCG was identified by a negative niacin test, absence of nitrate reductase and resistance to pyrazinamide and cycloserine. The diagnoses were further confirmed by a combination of an allele-specific polymerase chain reaction ated strain of Mycobacterium bovis, is the only available vaccine for the prevention of tuberculosis. Although complications are rare after BCG vaccination and the outcome is usually favourable, serious BCG infections can occur. We report two cases of M. bovis BCG infection in children, a 4-year-old immunocompetent girl and an 8-month-old immunodeficient boy. To our knowledge, this is the first report of BCG complications in children in which two recently developed polymerase chain reaction (PCR) based methods were used for rapid identification of M. bovis BCG infection. (PCR) and a multiplex PCR method. Based on the drug susceptibility results, treatment with rifampicin, isoniazid and ethambutol was instituted. One patient (Case 1) improved clinically and is well after treatment. However, the other patient with severe combined immunodeficiency died of disseminated BCG infection in spite of intensive anti-tuberculosis therapy. Although BCG is considered to be a safe vaccine, it should be kept in mind that complications related to BCG do occur.

School-aged homeless sheltered children's stressors and coping behaviors

The purpose of this study was to examine the stressors and coping behaviors of school-aged homeless children staying in shelters. A secondary analysis of interview data from 30 children, between the ages of 8 to 12 years, was used to delineate the stressors and coping behaviors. Homeless, family, self, peer, school, and violent behavior were the stressor categories derived from content analysis. The children expressed more stresses in the homeless, family, and self categories than in the other 3 categories. The coping behaviors from the content analysis were categorized by using Ryan-Wenger's (1992) coping taxonomy. The majority of the children's coping responses were in the social support, cognitive avoidance, and behavioral distraction categories. Nurses should assess each child's stressors and coping behaviors when providing care to homeless children, and assist the child in alleviating some stressors by strengthening one's coping behaviors.

The promoter region of the CTLA4 gene is associated with type 1 diabetes mellitus

The CTLA4 (cytotoxic T lymphocyte associated antigen-4) gene encodes the T cell receptor involved in the control of T cell proliferation and mediates T cell apoptosis. C-T polymorphism is present at position -318 from the ATG start codon in the promoter region of the gene. We report a study on the polymorphism in 347 unrelated children with type 1 diabetes mellitus (DM) (age at diagnosis 7.2+/-3.8 years) and their 260 healthy siblings as controls. Genotype C/C conferred a risk of type 1 DM (RR = 2.02, 95% CI 1.32-3.10, pc = 0.0033). The gene frequency of the C allele was higher in patients (RR = 1.91, 95% CI 1.28-2.84, pc = 0.0026). The gene frequency and phenotype frequency of the T allele were negatively associated with type 1 DM (RR = 0.52, 95% CI 0.35-0.78, pc = 0.0026 and RR = 0.49, 95% CI 0.32-0.76, pc = 0.0022, respectively). The frequency of genotype C/T was lower in patients (RR = 0.50, 95% CI 0.32-0.78, pc = 0.0051). This study demonstrates that nucleotide -318 C-T polymorphism of the CTLA4 gene is associated with type 1 DM. The promoter allele -318 C confers a risk of type 1 DM but allele -318 T confers protection against this disease.

Mitogen-stimulated TIS21 protein interacts with a protein-kinase-Calpha-binding protein rPICK1

TIS21 is induced transiently by PMA and a number of extracellular stimuli. Yeast two-hybrid screening has identified three TIS21 interacting clones from a rat cDNA library [Lin, Gary, Yang, Clarke and Herschman (1996) J. Biol. Chem 271, 15034-15044]. The amino acid sequence deduced from clone 5A shows 96.9% identity with the murine PICK1, a protein kinase Calpha (PKCalpha)-binding protein postulated to act as an intracellular receptor for PKC. A fusion protein of glutathione S-transferase and rPICK1 associates with the TIS21 translated in vitro, suggesting a direct physical interaction between these two proteins. TIS21 and rPICK1 are co-immunoprecipitated from NIH 3T3 cells overexpressing these two proteins. This indicates that the interaction also occurs in mammalian cells. Deletion of the PDZ domain at the N-terminus of rPICK1 abolishes its interaction with TIS21. A putative carboxylate-binding loop required for PICK1 to bind PKCalpha [Staudinger, Lu and Olson (1997) J. Biol. Chem 272, 32019-32024] is within this deleted region. Our results suggest a potential competition between TIS21 and PKC for binding to PICK1. We show that recombinant TIS21 is phosphorylated by PKC in vitro. The catalytic activity of PKC towards TIS21 is significantly decreased in the presence of rPICK1, whereas phosphorylation of histone by PKC is not affected. rPICK1 seems to modulate the phosphorylation of TIS21 through specific interactions between these two proteins. TIS21 might have a role in PKC-mediated extracellular signal transduction through its interaction with rPICK1.

Sequences at the 3' untranslated region of bamboo mosaic potexvirus RNA interact with the viral RNA-dependent RNA polymerase

The 3' untranslated region (UTR) of bamboo mosaic potexvirus (BaMV) genomic RNA was found to fold into a series of stem-loop structures including a pseudoknot structure. These structures were demonstrated to be important for viral RNA replication and were believed to be recognized by the replicase (C.-P. Cheng and C.-H. Tsai, J. Mol. Biol. 288:555-565, 1999). Electrophoretic mobility shift and competition assays have now been used to demonstrate that the Escherichia coli-expressed RNA-dependent RNA polymerase domain (Delta 893) derived from BaMV open reading frame 1 could specifically bind to the 3' UTR of BaMV RNA. No competition was observed when bovine liver tRNAs or poly(I)(C) double-stranded homopolymers were used as competitors, and the cucumber mosaic virus 3' UTR was a less efficient competitor. Competition analysis with different regions of the BaMV 3' UTR showed that Delta 893 binds to at least two independent RNA binding sites, stem-loop D and the poly(A) tail. Footprinting analysis revealed that Delta 893 could protect the sequences at loop D containing the potexviral conserved hexamer motif and part of the stem of domain D from chemical cleavage.

Congenital lactic acidosis: evaluation of the properties of the a199t natural variant of human pyruvate dehydrogenase e1alpha by in vitro mutation

One cause of congenital lactic acidosis is a mutation in the E1 alpha-subunit of the pyruvate dehydrogenase multienzyme complex. Little is known about the consequences of these mutations at the enzymatic level. Here we study the A199T mutation by expressing the protein in Escherichia coli. The specific activity is 25% of normal and the K(m) for pyruvate is elevated by 10-fold. Inhibitors of lactate dehydrogenase might be a useful therapy for patients with such mutations.

Overexpression of copper-zinc superoxide dismutase attenuates acute activation of activator protein-1 after transient focal cerebral ischemia in mice

BACKGROUND AND PURPOSE

Reactive oxygen species (ROS) have been implicated in reperfusion injury after focal cerebral ischemia (FCI). ROS are known to regulate the activity of transcription factors such as activator protein-1 (AP-1), which is a dimer consisting of members of the Jun and Fos families. We investigated the role of ROS in AP-1 activity after FCI using transgenic mice that overexpressed copper-zinc superoxide dismutase (SOD1) and that had reduced infarction volume after FCI.

METHODS

The SOD1 transgenic mice and their wild-type littermates were subjected to middle cerebral artery occlusion and reperfusion by intraluminal suture blockade. After 60 minutes of middle cerebral artery occlusion, mice were allowed to recover for 1, 2, and 4 hours before euthanasia. Protein expression of c-Jun and c-Fos was examined by immunohistochemistry and Western blotting. AP-1 DNA-protein binding activity was assessed by electrophoretic mobility shift assays.

RESULTS

In wild-type mice, immunohistochemistry demonstrated acute c-Jun and c-Fos activation in ischemic cortex and its outer boundary. Expression of both was reduced in SOD1 transgenic mice. Western blotting confirmed that SOD1 overexpression was associated with reduced c-Jun and c-Fos protein levels in ischemic brain. Electrophoretic mobility shift assays revealed that the ischemia-enhanced DNA binding activity observed in wild-type mice was reduced in SOD1 transgenic mice. Supershift assays indicated that c-Jun participated in the bound AP-1 complex.

CONCLUSIONS

SOD1 overexpression prevents early activation of AP-1 after transient FCI in mice. This may block the expression of downstream target genes that are injurious, thereby reducing the infarction volume after transient FCI in mice.

Metabolic disturbance in obese children: glucose, insulin levels and lipid profile

Obesity is a common nutritional disorder among children and adolescents. The purpose of this study was to investigate the biochemical changes in obese children in Taiwan, in comparison with those observed by other authors. Children with weights above 120 percent of ideal body weight were considered obese. Serum glucose, insulin, uric acid, and creatinine levels and lipid profiles of 298 obese children (mean age 11.3 +/- 2.4 years, 158 boys) and 60 controls (mean age 11.6 +/- 2.2 years, 38 boys) were determined using accepted procedures. Demographic and serum biochemical characteristics were compared between obese and control groups overall and by gender. Serum glucose, insulin, cholesterol, and triglyceride levels, known risk factors for coronary heart disease, were higher in the obese patients than in the control group. Early treatment and prevention of childhood obesity may keep the metabolic disturbance from deteriorating and becoming risk factors for coronary heart disease.

Intra-thoracic failure pattern and survival status following 3D conformal radiotherapy for non-small cell lung cancer: a preliminary report

BACKGROUND

To study the intra-thoracic failure pattern, clinical target volume (CTV) and survival status following 3D conformal radiotherapy (3DCRT) boost for non-small cell lung cancer (NSCLC).

METHODS

From May 1994 through June 1998, 33 patients (26 male, seven female) with NSCLC were treated with a complete course of radiotherapy (RT) in our institute. Group A included 10 patients receiving radical operation and adjuvant postoperative RT. The other 23 patients (groups B and C) received definitive radiotherapy as local treatment. Among them there were seven cases as group B (stage I-II) and 16 cases as group C (stage III). Fifteen (15/33) patients received chemotherapy. The radiotherapy strategy constituted conventional AP/PA radiotherapy (RT) 19.8-45 Gy (median 39.6 Gy) plus 3DCRT boost 6-34.2 Gy (median 20 Gy). The median total tumor dose was 59.6 Gy (ranging from 39.8 to 64.8 Gy). Patients were followed up regularly (6/33) or until their death (27/33). Nineteen patients received follow-up chest computed tomography (CT). The relationship between intra-thoracic failure found by chest CT and the initial RT and boost RT fields was analyzed. Local failure was defined as one of the following: clinical disease progression, CXR progression or relapse noted by CT. The overall survival (OS) and local failure free survival (LFF) were obtained using the Kaplan-Meier method.

RESULTS

Sixteen intra-thoracic failures were noted in 15 follow-up chest CT examinations, which included nine in-field relapses, three partial in-field relapses and four out-field relapses. The 2-year OS and LFF for groups A, B and C were 78.8/59.2, 14.2/16.7 and 6.2/7.1% respectively. RTOG grade III/IV complications included one pneumothorax (RTOG grade III).

CONCLUSION

Our retrospective study showed that selective omission of contralateral mediastinal lymph node station irradiation may be appropriate in RT for NSCLC. Chest wall and pleural relapses may not be a negligible cause of intra-thoracic failure after RT for NSCLC.

Effect of percent free prostate-specific antigen measurement on improving the specificity of serum prostate-specific antigen testing in Taiwanese patients

BACKGROUND AND PURPOSE

Measurement of percent free prostate-specific antigen (fPSA) has been shown to enhance the diagnostic performance of traditional serum PSA determination. We sought to determine whether measurement of percent fPSA could improve the specificity of serum total PSA testing in the detection of prostate cancer in Taiwanese patients with intermediate serum PSA concentrations.

METHODS

The medical records of 211 patients examined from March 1998 through March 2000 were analyzed retrospectively; all had a serum total PSA concentration of between 4.1 and 20.0 ng/mL and negative digital rectal examination (DRE) findings, and had undergone a prostate biopsy. Biopsy results were correlated with the serum total PSA concentration and percent fPSA, which were determined using a microparticle enzyme immunoassay. Percent fPSA was calculated as the ratio of fPSA to total PSA multiple by 100. The sensitivity and specificity were calculated and the receiver operating characteristic (ROC) curves were generated from different cutoff values of percent fPSA and total PSA.

RESULTS

Thirty-four patients (16.1%) had positive biopsy results (prostate cancer). Patients with positive biopsy results had significantly lower percent fPSA values than those with negative results (11.7% vs 16.0%, p < 0.001). Patients with a lower percent fPSA (< 10%) had a higher probability of a positive biopsy result than those with a high percent fPSA (> 20%) (positive biopsy rate, 29% vs 10%, p < 0.05). Using a cutoff value of 25% fPSA or below, the sensitivity, specificity, and positive predictive value in differentiating patients with positive biopsy results from those with negative results were 97%, 13%, and 18%, respectively. Consequently, 27 unnecessary biopsies could have been avoided at the cost of missing one cancer. The area under the ROC curve was 0.68 for percent fPSA and 0.63 for total PSA (p > 0.05).

CONCLUSIONS

For Taiwanese patients with a serum PSA concentration of between 4.1 and 20.0 ng/mL, the incidence of prostate cancer is relatively low; measurement of percent fPSA only weakly enhances the specificity of serum PSA testing in detecting prostate cancer.

Clinical and histopathological characteristics of primary cutaneous amyloidosis in 794 Chinese patients

BACKGROUND

Primary cutaneous amyloidosis (PCA) is not uncommon in Chinese patients. The disease is usually persistent and quite pruritic. Patients who suffer from this disease usually respond poorly to conventional treatment. We thus reviewed our cases of PCA to discuss the clinical and pathological characteristics.

METHODS

Seven hundred and ninety-four Chinese patients with PCA who visited the Department of Dermatology, Taipei Veterans General Hospital during the last 26-year period were examined and retrospectively studied. The diagnosis in these patients was confirmed by histopathological studies.

RESULTS

Among the many types of PCA, lichen amyloidosis was the most common clinical variant (67%). Pure cases of macular amyloidosis accounted only 8% and were often associated with lichenoid lesions to form biphasic amyloidosis, which was composed of 25% in our series. Other rare types of PCA, such as nodular, anosacral, and vitiliginous amyloidosis, always required a careful differential diagnosis clinically from other similar skin disorders. In addition, 56 familial cases were found. Histopathologically, the most common epidermal findings of PCA were hyperkeratosis, irregular acanthosis with thinning of rete ridges, and expansion of dermal papillae by amyloid deposition. Special histochemical stains were helpful for confirming the existence of amyloid.

CONCLUSIONS

Our study represents the largest number of cases of PCA collected to date. Based on the data, most cases are sporadic, except 56 familial cases which may suggest the possible genetic role. Rare types of PCA, such as anosacral and vitiliginous amyloidosis which need special attention, compose a diagnostic challenge to a dermatologist. Histochemically, H&E stain can give a primary clue for the diagnosis of amyloidosis and crystal violet stain is a very simple and sensitive method to detect the existence of amyloid.