Differential expression of p53 gene family members p63 and p73 in head and neck squamous tumorigenesis

p73 and p63 are recently cloned genes that share considerable structural and functional homologies with the p53 tumor suppressor gene. These genes, unlike p53, express multiple mRNA isoforms with variable biologic functions, and their suppressor nature has yet to be confirmed. To determine the interrelationship between these genes in the tumorigenesis of head and neck squamous carcinoma (HNSC), we performed immunohistochemical analyses of their protein products and compared the data with clinicopathologic parameters in 38 patients. In histologically normal epithelium, p53 and p73 showed similar basal and/or parabasal expression, but that of p53 was weaker and discontinuous. p63 staining was noted in more suprabasal cellular layers and was stronger. In dysplasias, all three markers manifested variable but gradual increase in extent and intensity of cellular expression with histologic progression. In carcinomas, p63 was the most frequently expressed (94.7%), followed by p73 (68.4%) and p53 (52.6%). Significant statistical correlation was noted only between p63 and p73 expressions (P =.04). Although no statistical correlation was found between p53 and p63 or p73, p53-negative tumors overexpressed either p63 or p73. p73 expression was associated with distant metastasis and perineural/vascular invasion. Our study indicates that (1) p63 and p73 expression may represent an early event in HNSC tumorigenesis, (2) the lack of correlation between p73 or p63 and p53 expression suggests an independent and/or compensatory functional role, (3) p73 expression may play a part in HNSC progression, and (4) p73 and p63 may function as oncogenes in the development of these tumors.     

A novel missense mutation (I344K) in the SPG4gene in a Korean family with autosomal-dominant hereditary spastic paraplegia

 Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower extremities. Among eight loci linked with autosomal-dominant (AD)-HSP, the SPG4 locus on chromosome 2p22 accounts for about 40% of all patients. Recently, mutations in a new member of the AAA protein family, called spastin, have been identified as responsible for SPG4-linked AD-HSP. Here, we describe a novel missense mutation (c.1031T>A; I344K) in exon 7 of the SPG4 gene identified in a Korean family with typical clinical features of pure AD-HSP. The mutation affects the third amino acid of the highly conserved AAA cassette domain, which is the most fore part of the domain altered by a missense mutation reported so far. Clinical presentations of affected individuals carrying the I344K mutation were not different from those of pure AD-HSP with SPG4 mutations reported previously. However, it is noteworthy that neither urinary dysfunction nor involvement of upper extremities was noticed in this family. To our knowledge, this is the first report of genetically confirmed AD-HSP in Korea. Received: February 20, 2002 / Accepted: May 21, 2002     

Antigenic and immunogenic investigation of B-cell epitopes in the nucleocapsid protein of peste des petits ruminants virus

Attempts were made to identify and map epitopes on the nucleocapsid (N) protein of peste des petits ruminants virus (PPRV) (Nigeria75/1 strain) using seven monoclonal antibodies (MAbs) and deletion mutants. At least four antigenic domains (A-I, A-II, C-I, and C-II) were identified using the MAbs. Domains A-I (MAb 33-4) and A-II (MAbs 38-4, P-3H12, and P-13A9) were determined to be located on the amino-terminal half (amino acids [aa] 1 to 262), and domains C-I (P-14C6) and C-II (P-9H10 and P-11A6) were within the carboxy-terminal region (aa 448 to 521). Nonreciprocal competition between A-II MAbs and MAbs to C-I and C-II domains was observed, indicating that they may be exposed on the surface of the N protein and spatially overlap each other. Blocking or competitive enzyme-linked immunosorbent assay studies using PPRV serum antibodies revealed that epitopes on the domains A-II and C-II were immunodominant, whereas those on the domains A-I and C-I were not. The competition between MAb and rinderpest virus (RPV) serum antibodies raised against RPV strain LATC was found in two epitopes (P-3H12 and P-13A9) on the domain A-II, indicating that these epitopes may cause cross-reactivity between PPRV and RPV. Identification of immunodominant but PPRV-specific epitopes and domains will provide the foundation in designing an N-protein-based diagnostic immunoassay for PPRV.     

Autologous stem cell transplantation in the treatment of refractory rheumatoid arthritis

The concept of using high-dose immunosuppressive treatment (HDIT) with autologous stem cell transplantation (ASCT) to treat patients with refractory rheumatoid arthritis has been provided by animal studies and anecdotal case reports. Over the past five years, an increasing number of patients with refractory rheumatoid arthritis have received HDIT with ASCT as an adjunct to intense immunosuppression. Here, we present a case of refractory rheumatoid arthritis in a 54-yr-old woman using HDIT with ASCT. Peripheral blood stem cells were mobilized with cyclophosphamide (4 g/m(2)) followed by G-CSF (5 microg/kg/day). Leukapheresis continued daily until the number of harvested progenitor cells reached 2 x 10(6) CD34+ cells/kg after CliniMax CD34+ positive selection. For HDIT, high-dose cyclophosphamide (total dose 200 mg/kg) and antithymocyte globulin (total dose 90 mg/kg) were administered and CD34+ cells were infused 24 hr after HDIT. The patient tolerated the treatment well but experienced an episode of neutropenic fever. She achieved an early dramatic improvement of joint symptoms during therapy. Fifty percent of improvement of rheumatoid arthritis by the American College of Rheumatology (ACR 50) preliminary definition was fulfilled during the 6 months following ASCT. Although further long-term follow-up is required, the patient's activity of arthritis has been stable since receiving HDIT with ASCT.     

Prevalence and risk factors of urinary stones in Koreans.

To estimate the prevalence of urinary stone disease in Koreans, and to determine the inter-relationships between urinary stone disease and various epidemiological factors, 1,521 controls and 1,177 cases with urinary stones were evaluated. Of special interest in this study were: 1) proportion of past urinary stone history among controls; 1.9% 2) the point prevalence rate of urinary stones among controls; 0.2% 3) the recurrence rate of urinary stones (the proportion of past history of urinary stone) among cases; 56.8% 4) high incidences (76.3%) in the thirties to the fifties among cases 5) the risk factors for urolithogenesis; obesity [higher than 25 of BMI (body mass index, weight/height2)], more than 10 year-experience as a production worker, past stone history, familial stone history, low physical activity (< 2,000 Kcal/day), and low intake of fruit. However, the well-known risk factors for urinary stones; over intake of meat or fish and milk or dairy products, perspiration, amount and kind of drinking water, and stress unexpectedly were not significantly different between the controls and the cases.     

Differential involvement of GABA system in mediating behavioral and neurochemical effect of acupuncture in ethanol-withdrawn rats

In our previous study we demonstrated that acupuncture at Shenmen (HT7) points suppressed a decrease of accumbal dopamine (DA) release in ethanol-withdrawn rats. Furthermore, here we found that it inhibited behavioral withdrawal signs of ethanol. In an effort to better understand the mechanisms underlying this inhibition, the potential role of GABA receptor system in acupuncture was investigated. Male Sprague–Dawley rats were treated with 3 g/kg/day of ethanol (20%, w/v) or saline by intraperitoneal injection for 21 days. Following 48 or 72 h of ethanol withdrawal, acupuncture was applied at bilateral HT7 for 1 min. The selective GABA_A antagonist bicuculline and the selective GABA_B antagonist SCH 50911 were injected intraperitoneally 20 min before acupuncture, respectively. Importantly, suppressive effects of acupuncture on DA deficiency were completely abolished by SCH 50911, but not by bicuculline, whereas ameliorating effects of acupuncture on ethanol withdrawal syndrome were completely blocked either by SCH 50911 or bicuculline. These results suggest that acupuncture at specific acupoint HT7 may normalize the DA release in the mesolimbic system and attenuate withdrawal syndrome through the GABA_B receptor system in ethanol-withdrawn rats.     

Serum neopterin for early assessment of severity of severe acute respiratory syndrome

Neopterin and C-reactive protein (CRP) concentrations were determined in serum samples from 129 severe acute respiratory syndrome (SARS) patients and 156 healthy blood donors. In the patients with confirmed SARS, an early neopterin elevation was detected already at the day of onset of symptoms and rose to a maximum level of 45.0 nmol/L 3 days after the onset. All SARS patients had elevated neopterin concentrations (>10 nmol/L) within 9 days after the onset. The mean neopterin concentrations were 34.2 nmol/L in acute sera of SARS patients, 5.1 nmol/L in convalescent sera, and 6.7 nmol/L in healthy controls. In contrast, the mean CRP concentrations in both acute and convalescent sera of SARS patients were in the normal range (<10 mg/L). Serum neopterin level in SARS patients was associated with fever period and thus the clinical progression of the disease, while there was no significant correlation between the CRP level and the fever period. Serum neopterin may allow early assessment of the severity of SARS. The decrease of neopterin level was found after steroid treatment, which indicates that blood samples should be collected before steroid treatment for the neopterin measurement.     

Characterization of erythromycin-resistant Streptococcus pneumoniae in Korea, and In Vitro activity of telithromycin against erythromycin-resistant Streptococcus pneumoniae

To characterize the phenotypes and genotypes of erythromycin-resistant clinical isolates of Streptococcus pneumoniae in Korea and to evaluate the in vitro activity of telithromycin against these erythromycin-resistant isolates, we tested a total of 676 isolates of S. pneumoniae collected from 1997 to 2002 in a tertiary hospital in Seoul, Republic of Korea. MICs for erythromycin and telithromycin were determined by the agar dilution method. The macrolide resistance phenotypes of erythromycin-resistant isolates were determined by the erythromycin- clindamycin-rokitamycin triple disk (ECRTD) and MIC induction tests, whereas their macrolide resistance genotypes were determined by PCR for the erm(B), erm(A), subclass erm(TR), and mef genes. To discriminate between mef(A) and mef(E), PCR-restriction fragment length polymorphism (RFLP) analyses were performed. Of the 676 S. pneumoniae isolates, 459 (67.9%) were resistant to erythromycin. Of the 459 erythromycin-resistant isolates, 343 (74.7%) were assigned to the cMLS phenotype, 48 (10.4%) to the iMcLS phenotype, 4 (0.9%) to the iMLS phenotype, and 64 (14.0%) to the M phenotype. The erm(B) gene was detected in 251 (54.6%) isolates, the mef gene was detected in 64 (14.0%), and both the erm(B) and mef genes were detected in 144 (31.4%) isolates. All of the mef genes detected were identified as mef(E). Of the 459 erythromycin- resistant isolates, all but one were susceptible to telithromycin. The MIC(50)/MIC(90) to telithromycin of isolates carrying erm(B), mef(E), and both genes was 0.06/0.5 microg/ml, 0.03/0.125 microg/ml, and 0.5/1.0 microg/ml, respectively. Although the MICs of telithromycin for the erythromycin-resistant isolates varied according to genotype, telithromycin was very active against these erythromycin-resistant S. pneumoniae.