A scytalone dehydratase gene from Ophiostoma floccosum restores the melanization and pathogenicity phenotypes of a melanin-deficient Colletotrichum lagenarium mutant

Scytalone dehydratase is involved in the production of fungal dihydroxynaphthalene (DHN) melanin. We have isolated and characterized OSD1, a gene encoding scytalone dehydratase from the sap-staining fungus Ophiostoma floccosum by PCR-based cloning. Sequence analysis suggests that the OSD1 gene encodes a protein of 216 amino acids with a molecular weight of 24.2 kDa that shows 51-70% sequence identity to other scytalone dehydratases. The cloned OSD1 contains two introns of 76 bp and 63 bp in length, and is the longest scytalone dehydratase gene sequence so far reported. Transformation of a DHN melanin-deficient, non-pathogenic, mutant of Colletotrichum lagenarium with the OSD1 gene restored melanin production and pathogenicity. The ability of the mutant to produce the OSD1 gene product was confirmed by RT-PCR analysis. These data show that the cloned OSD1 gene product can function in the DHN melanin biosynthetic pathway in C. lagenarium.

Crystallization of a complex between human CDK6 and a virus-encoded cyclin is critically dependent on the addition of small charged organic molecules

Human CDK6 plays an important role in controlling entry into the eukaryotic cell cycle. An activated complex of human CDK6 with a viral cyclin from herpesvirus saimiri was purified to homogeneity and crystallized using polyethylene glycol 3350 as precipitant. Crystallization was critically dependent on a narrow range of calcium acetate concentration and the presence of sulfo-betaine 201 as additive. Crystals belong to the hexagonal space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 70.14, c = 448.77 A, gamma = 120 degrees, and diffract X-rays to at least 3.1 A resolution.

Dependence of malformation upon gestational age and exposed dose of gamma radiation

In order to evaluate the importance of gestational age and the dose-incidence relationship by gamma radiation, pregnant ICR mice at gestational days from 2.5 to 15.5 days post-coitus (p.c.) were exposed to a single dose of 2.0 Gy and also at day 11.5 after conception, which was the most sensitive stage for the induction of major congenital malformations. The animals were sacrificed on day 18 of gestation and the fetuses were examined for mortality, growth retardation, changes in head size and other morphological abnormalities. The only demonstrable effect of irradiation during the pre-implantation period was an increase in prenatal mortality. Resorptions were maximal on exposure at day 2.5 after conception. The pre-implantation irradiated embryos which survived did not show any major fetal abnormalities. A small head, growth retardation, a cleft palate, dilatation of the cerebral ventricle, a renal pelvis, and abnormalities of the extremities and tail after exposure were prominent during the organogenesis period, especially on day 11.5 of gestation. As for the dose-incidence relationship, the incidence of a small head, growth-retarded fetuses, a cleft palate, dilatation of cerebral ventricle and abnormalities of the extremities in live fetuses rose as the radiation dose increased. The result indicated that the late period of organogenesis in the development of the brain, skull and extremities of a mouse was a particularly sensitive phase. The threshold doses of radiation that induced a cleft palate and dilatation of the cerebral ventricle, and abnormal extremities were between 1.0 and 2.0 Gy, and between 0.5 and 1.0 Gy, respectively.

Modification of radiation response in mice by Panax ginseng and diethyldithiocarbamate

The aim of this study was to determine the effect of Panax ginseng and its fractions on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells of mice irradiated with high- and low-dose of gamma-irradiation. The radioprotective effect of ginseng was compared with the effect of diethyldithiocarbamate (DDC). Ginseng administration before irradiation protected the jejunal crypts (p < 0.005), increased the formation of endogenous spleen colony (p < 0.005) and reduced the frequency of radiation-induced apoptosis (p < 0.05). The radioprotective effect on jejunal crypts and apoptosis in the DDC-treated group appeared similar to that in the ginseng--treated groups. Treatment with DDC showed no significant modifying effects on the formation of endogenous spleen colony. In the experiment on the effect of fractions of ginseng, the result indicated that the lipophilic non-polar compounds (Fraction 1), lipophilic-acidic compounds (Fraction 2), free sugars (Fraction 7) and saponin compounds (Fraction 8) might have a major radioprotective effect. Although the mechanisms of this inhibitory effect remain to be elucidated, these results indicated that ginseng might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to fully characterize the protective nature of ginseng extract and its components.

Lagophthalmos surgery in leprosy: findings from a population-based survey in Korea

Lagophthalmos continues to be a serious problem in cured leprosy patients. We conducted a population-based survey of lagophthalmos surgical coverage (LSC), barriers to lagophthalmos surgery and outcome of lagophthalmos surgery in leprosy patients in South Korea. In our survey, there were 60 patients with lagophthalmos who had needed surgery (> 5 mm gap), 34 of whom had received surgery, resulting in a lagophthalmos surgery coverage of 57%. Among the 34 patients who had received lagophthalmos surgery, 18 needed further surgery. Among those who had never had surgery, none of the demographic indicators predicted surgical uptake; the primary reason given for failure to have surgery was lack of knowledge about it. Outcome of surgery (by eye) showed that 29% of eyes still had a gap of 5 mm or more. The frequency of symptoms (tearing, blurring of vision, pain, etc.) was high. Even in settings with a good eye care infrastructure, such as Korea, uptake of surgery can still be low and results may not be satisfactory to patients. There is a need for practical guidelines for leprosy control programmes in the areas of (a) patient recognition, (b) patient education, (c) monitoring the uptake of surgery, and (d) monitoring the outcome of surgery to ensure the best possible outcome.

Induction of apoptosis in p53-deficient human hepatoma cell line by wild-type p53 gene transduction: inhibition by antioxidant

We investigated the role of wild-type (wt)-p53 as an inducer of apoptotic cell death in human hepatoma cell lines. Following the retrovirus-mediated transduction of the wt-p53 gene, Hep3B cells lacking the endogenous p53 expression began to die through apoptosis in 4 h. They showed a maximal apoptotic death at 12 h, whereas HepG2 cells expressing endogenous p53 did not. However, the transduction of the wt-p53 gene elicited growth suppression of both Hep3B and HepG2 cells. P21(WAF1/CIP1), a p53-inducible cell cycle inhibitor, was induced, not only in Hep3B cells undergoing apoptosis, but also in HepG2 cells. The kinetics of the p21(WAF1/CIP1) induction, DNA fragmentation, and growth suppression of the Hep3B cells showed that DNA fragmentation and growth suppression progressed rapidly following p21(WAF1/CIP1) accumulation. N-acetyl-cysteine or glutathione, potent antioxidants, strongly inhibited the DNA fragmentation, but did not reduce the elevated level of p21(WAF1/CIP1). These findings suggested that p21(WAF1/CIP1) was not a critical mediator for the execution of p53-mediated apoptosis, although it contributed to the growth inhibition of cells undergoing apoptosis. Furthermore, p53-mediated apoptosis could be repressed by antioxidants.

Synthesis and biological activity of novel epothilone aziridines

[reaction: see text]. A series of 12alpha,13alpha-aziridinyl epothilone derivatives were synthesized in an efficient manner from epothilone A. The final semisynthetic route involves a formal double-inversion of stereochemistry at both the C12 and C13 positions. All aziridine analogues were tested for effects on tubulin binding polymerization and cytotoxicity. The results indicate that the aziridine moiety is a viable isosteric replacement for the epoxide in the case of epothilones.

Traumatic perilymphatic fistulas in children: etiology, diagnosis and management

Post-traumatic perilymphatic fistulas have been described following ear and temporal bone injury, particularly in the setting of temporal bone fractures. However, indications for exploratory surgery in cases of trauma without temporal bone fracture are vague and not well described. We describe three children who presented with symptoms suggestive of perilymphatic fistula (PLF) without an associated temporal bone fracture: two with penetrating tympanic membrane injuries and one with blunt temporal bone trauma. All had symptoms of hearing loss and vestibular disturbance. Two of the children cooperated with ear-specific audiologic assessment, which demonstrated sensorineural hearing loss (SNHL) on the traumatized side. The third child showed audiometric evidence of a SNHL on the injured side, but due to his age, the degree of severity of the SNHL was unable to be appropriately addressed prior to the patient being surgically managed. All three children underwent exploratory surgery and were found to have bony defects in the region of the oval window. All were repaired with fascial grafts to the oval and round windows with complete resolution of vestibular symptoms. However, two of the three patients with documented post-operative audiograms suffered from persistent SNHL on the injured side. We conclude that exploratory middle ear surgery is indicated in patients suffering from blunt or penetrating temporal bone or middle ear trauma who demonstrate persistent vestibular symptoms, sensorineural hearing loss or radiographic evidence of oval window pathology. As this is a limited number of patients, a larger series may be warranted to study the actual incidence of post-traumatic PLF in the child with persistent hearing loss and vertigo after head or ear trauma.

Immobilization of poly(ethylene glycol) or its sulfonate onto polymer surfaces by ozone oxidation

A novel surface modification method has been developed to improve biocompatibility of polymeric biomaterials. This approach involves ozonation and then followed by graft polymerization with acrylates containing PEG, sulfonated PEG or by coupling of PEG derivatives. All the reactions were confirmed by ATR FT-IR and ESCA. The degree of ozonation measured by the iodide method was dependent on the ozone permeability of the polymers used. Surface hydrophilicity was investigated by measuring the contact angles. Ozonation itself yielded a slight increase in hydrophilicity and a decrease in platelet adhesion, but PEG immobilization showed a significant effect on surface hydrophilicity and platelet adhesion to confirm well-known PEG's passivity which minimize the adhesion of blood components on polymer surfaces. Both graft polymerization and coupling were effective for PU. In contrast, only grafting gave enough yields for PMMA and silicone. Platelet adhesion results demonstrated that all PEG modified surfaces adsorbed lower platelet adhesion than untreated or ozonated ones. Polymers coupled with sulfonated PEG exhibited the lowest platelet adhesion when compared with control and PEG coupled ones by virtue of the synergistic effect of non-adhesive PEG and negatively charged SO3 groups. This PEG or sulfonated PEG immobilization technology using ozonation is relatively simple for introducing uniform surface modification and therefore very useful for practical application of blood contacting medical devices.

Deep brain stimulator electrodes used for lesioning: proof of principle

OBJECTIVE

Patients with chronically implanted deep brain stimulator (DBS) electrodes can encounter complications requiring hardware removal. We assessed the safety and efficacy of using implanted DBS electrodes to create a therapeutic lesion before their removal.

METHODS

Revision or removal of the DBS electrodes was required in two patients who had previously undergone DBS implantation. We conducted a series of in vitro experiments to confirm that the DBS electrodes could be used to generate radiofrequency lesions and to assess the relationship between radiofrequency parameters and lesion size. With this information, and with the approval of the hospital ethical review board, implanted electrodes were used to create incremental radiofrequency lesions in the thalamus in one patient and in the subthalamic nucleus in another. The procedures were performed under local anesthesia with contiguous contacts of the DBS lead connected to the active and reference sites of the RF generator to create a bipolar lesion.

RESULTS

A 51-year-old man with essential tremor and a thalamic DBS required repeated battery changes secondary to tolerance and high voltage demands. Rather than replacing the battery, a radiofrequency thalamotomy was performed by using the existing left DBS electrode. At the 6-month follow-up examination, successful lesioning provided near complete tremor control. A second patient, a 50-year-old man with Parkinson's disease who had undergone bilateral subthalamic deep brain stimulation, developed skin erosion over the DBS hardware. A subthalamic nucleus lesion was made through the right DBS electrode. Lesion position and size were confirmed with magnetic resonance imaging.

CONCLUSION

Lesions can be made through chronically implanted DBS electrodes in a safe, graded fashion and can produce therapeutic benefit.

CYP2D6*4 polymorphism is not associated with Parkinson's disease and has no protective role against Alzheimer's disease in the Korean population

CYP2D6*4 polymorphism is reported to be associated with Parkinson's disease (PD) and to have protective role against Alzheimer's disease (AD). Such findings are not extensively studied in the Oriental population, especially Koreans. The effects of CYP2D6*4 polymorphism on AD and PD were investigated by polymerase chain reaction-restriction fragment length polymorphism in Korean subjects. Heterozygous mutant allele was found in four of 93 patients with PD, 0 of 32 patients with AD and one of 121 control subjects (59 stroke, 59 normal controls and four other psychiatric disorders), but no homozygous mutant allele was found. There were no statistically significant differences between the AD group and controls, and between the PD group and controls. In conclusion, we suggest that CYP2D6*4 polymorphism does not confer susceptibility to PD in the Korean population. Also, due to such a rare occurrence of the CYP2D6*4 polymorphism, we can not confirm the protective role of the polymorphism against AD in the Korean population.

A case of successful primary coronary intervention for the total occlusion of left main stem with the aid of abciximab

A 61-yr-old male patient presented with severe chest pain with cardiogenic shock due to an extensive anterolateral myocardial infarction. Two-dimensional echocardiogram showed severe left ventricular systolic dysfunction (ejection fraction=17%). Emergent coronary angiogram obtained immediately after placing temporary pacing electrode revealed total thrombotic occlusion in the left main stem. We performed direct coronary intervention using kissing balloon technique with the aid of Abciximab (ReoPro) infusion. Residual stenosis with thrombus remained even after high pressure balloon dilatations, therefore we placed two stents, one in the ostia of left anterior descending (LAD) and the other in left circumflex artery (LCX). Coronary angiogram after kissing stents showed improved LAD and LCX flows without residual stenosis. Chest pain resolved and blood pressure normalized after coronary intervention. The whole procedure time was 15 min. Follow-up coronary angiogram taken one week later showed patent previous stented arteries, and echocardiography demonstrated 40% of left ventricular ejection fraction. The clinical course for one-year follow-up was uneventful.

Epidemiological significance of sero-positive inhabitants against sparganum in Kangwon-do, Korea

Sparganum is a plerocercoid of pseudophyllidean tapeworms, Diphyllobothrium or Spirometra spp. Human sparganosis is endemic mainly in East and Southeast Asian countries where the custom of eating raw snake or frog meat, or poulticing with snake's skin exists. From January 1995 to November 1999, an epidemiological survey was undertaken to evaluate the serum levels of anti-sparganum specific IgG antibodies in Whachon-gun residents, Korea. An enzyme- linked immunosorbent assay (ELISA) and immunoblot analysis of the sera from 316 subjects were used. In addition, a stool examination from 416 inhabitants and questionnaires regarding the consumption of raw meat were given. Out of 416 inhabitants examined coprologically, one was infected with Clonorchis sinensis and two were infected with Metagonimus spp. The sera from 36 inhabitants (11.4 %) showed a positive reaction to the sparganum antigen. Out of these 36 inhabitants, the sera from 25 people were examined 7, 19, and 50 months later. The sera were found to still show positive reactions without any remarkable changes of anti-sparganum specific antibody titers except for one. An analysis of the questionnaires suggested that a history of eating of raw snakes or frogs was important risk factor for clinical or covert sparganosis (odd ratio=15.6 and 3.1, respectively).

Differential roles of interleukin-18 (IL-18) and IL12 for induction of gamma interferon by staphylococcal cell wall components and superantigens

The roles of endogenous cytokines induced by either intact staphylococcal microorganisms or staphylococcal exotoxins were examined using human whole-blood cultures. To accomplish this, interleukin-18 binding protein (IL-18BP) and tumor necrosis factor binding protein (TNFbp) were used to neutralize IL-18 and TNF, respectively, whereas an anti-IL-12 monoclonal antibody was used to neutralize IL-12 and the IL-1 receptor antagonist (IL-1Ra) was used to block IL-1 receptors. Heat-killed Staphylococcus epidermidis and Staphylococcus aureus, as well as the staphylococcal superantigens toxic shock syndrome toxin-1 (TSST-1) and staphylococcus enterotoxin B (SEB) induced gamma interferon (IFN-gamma) production. Staphylococcus spp.-induced production of IFN-gamma required the presence of endogenous IL-18, IL-12, and TNF. In contrast, TSST-1-induced IFN-gamma was not significantly reduced in the presence of IL-18BP, anti-IL-12 antibodies, IL-1Ra, or anti-TNFbp. SEB-induced IFN-gamma was significantly inhibited only by anti-IL-12 antibodies, indicating that endogenous IL-18, IL-1, and TNF are not required for SEB-induced IFN-gamma. In conclusion, the mechanisms of IFN-gamma stimulation by intact staphylococcal microorganisms and by exotoxins differ, and this is likely due to the different receptors which are triggered on the cell membranes. In contrast to its role in the interactions between staphylococci and host cells, IL-18 does not appear to play a major role in superantigen-induced IFN-gamma.

In vitro establishment of cis-diammine-dichloroplatinum(II) resistant lung cancer cell line and modulation of apoptotic gene expression as a mechanism of resistant phenotype

After exposure of H460 cells to an increasing concentrations of cis-diammine-dichloroplatinum(II) (cisplatin, CDDP) for 6 months, cisplatin resistant cells were isolated (H460/CIS). The biologic behaviors of H460 and H460/CIS cells were tested using animal experiments. Only the resistant cells developed lung metastases despite cisplatin treatment. The characteristics of H460/CIS cells are as follows, MTT analyses revealed that H460/CIS cells were markedly resistant to cisplatin compared with their parental cells. Also, H460/CIS cells exhibited cross-resistance to DNA damaging agents such as doxorubicin (DXR) and etoposide. Cisplatin treatment dramatically increased p53 expression in parental cells but not in H460/CIS cells which expressed basal levels of p53. Without cisplatin treatment, Bcl-2 and Bax were expressed in H460/CIS cells, but not in parental cell. Our data suggested that p53, Bax and Bcl-2 were up-regulated in H460/CIS cells. These changes could explain some of the mechanisms of cisplatin resistance. Thus, H460/CIS could be useful to investigate the mechanisms of drug resistance to cisplatin including apoptotic gene expressions conferring drug resistance, thereby making progress in the treatment of cisplatin-resistant tumor cells.

Enhancement of tumor radioresponse by combined chemotherapy in murine hepatocarcinoma

BACKGROUND AND AIMS

Recent studies have shown that local radiotherapy can be an effective component of the treatment for hepatocellular carcinoma. To further improve therapeutic efficacy, use of drugs that can beneficially interact with radiation has been suggested. The purpose of this study was to identify drugs that can enhance radioresponse of murine hepatocarcinoma.

METHODS

C3H/HeJ mice bearing 8 mm tumors of murine hepatocarcinoma, HCa-I, were treated with 25 Gy radiation and one of the following drugs: 5-Fu, 150 mg/kg; adriamycin, 8 mg/kg; cisplatin, 6 mg/kg; paclitaxel, 40 mg/kg; and gemcitabine, 50 mg/kg. Tumor response to the treatment was determined by the use of a tumor growth delay assay and by an enhancement factor. The apoptotic level was assessed in tissue sections. The expression of regulating molecules was analyzed by using western blotting for p53, Bcl-2, Bax, Bcl-XL, Bcl-XS, and p21(WAF1/CIP1).

RESULTS

Among the drugs tested, only gemcitabine enhanced the antitumor effect of radiation, with an enhancement factor of 1.6. The induction of apoptosis by a combination of gemcitabine and radiation was shown as only an additive level. In the analysis of radiation-induced expression of regulating molecules, the most significant change by combining gemcitabine with radiation was the activation of p21(WAF1/CIP1).

CONCLUSION

Gemcitabine is the first to show an enhancement of radioresponse of murine hepatocarcinoma when combined with radiation. The key element of enhancement is thought to be p21(WAF1/CIP1).

Cloning and disruption of a phenylalanine ammonia-lyase gene from Ustilago maydis

The enzyme L-phenylalanine ammonia-lyase (PAL) catalyzes the non-oxidative deamination of L-phenylalanine to form trans-cinnamic acid and ammonia. This enzyme is universally present in higher plants and it catalyzes the starting reaction for a central pathway that generates hundreds of different phenylpropanoid metabolites. Genes encoding PAL have been identified in fungi, but the role of the enzyme has not been determined. We cloned and characterized a gene that encodes PAL from the phytopathogenic fungus Ustilago maydis and we constructed fungal strains carrying a null mutation in the gene. These mutants behaved like wild-type strains in terms of growth, mating, and pathogenicity. These results indicate that PAL does not play a major role in the life cycle of U. maydis under laboratory conditions.

Characterization of monoclonal antibodies against carcinoembryonic antigen (CEA) and expression in E. coli

Eight monoclonal antibodies (MAbs) against carcinoembryonic antigen (CEA) were characterized. Five clones are IgG(1), two clones are IgM and one clone is IgG(2b); all have kappa light chain. The affinities are in the range of 1.1 x 10(-7) approximately 2.4 x 10(-9) M; the affinities of two IgM clones could not be estimated because of their low enzyme-linked immunoadsorbent assay (ELISA) signal. Each clone was constructed as single-chain Fv (scFv) and expression was performed in E. coli. Four clones out of 8 could express scFv soluble to culture media and the expression was confirmed further by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The nucleotide and amino acid sequences of V(H) and V(L) of four scFvs were deduced and their family and subgroup were analyzed. We found that the clones that do not express the scFv have aberrant kappa chain (incorrect V/J recombination or stop codon); in contrast, their heavy chain sequences proved correct. The E. coli-expressed scFvs showed 1.5 x 3.4-fold lower affinities (2.8 x 10(-8) approximately 3.6 x 10(-9) M) than those of hybridoma-derived parental antibodies except the one clone (C5), which exhibited approximately 10(-6) M of affinity.

Cervical dermal sinus associated with dermoid cyst

We report a rare case of cervical dermal sinus associated with a dermoid cyst in a 10-month-old infant, who presented with a 1-month history of motor weakness of the right upper extremity. Magnetic resonance imaging showed an intradural extramedullary dermoid cyst extending from C3 to C4, which was connected with the skin dimple along the sinus tract. Total excision of the dermoid cyst and the sinus tract with C3-5 laminectomy resulted in good functional recovery.

Secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis : report of two cases

Amenorrhea is rarely presented as a manifestation of endocrinological disturbances in patients of chronic hydrocephalus. We describe two cases of secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis. Two female patients of age 30 and 20 yr presented with amenorrhea and increasing headache. Magnetic resonance images revealed marked, noncommunicating hydrocephalus without any tumorous lesion. In one patient, emergent extraventricular drainage was necessary because of progressive neurological deterioration. Each patient underwent surgical intervention for the hydrocephalus-ventriculoperitoneal shunt and endoscopic third ventriculostomy. Both resumed normal menstruation continuing so far with further normal menstrual bleeding. These two cases and others reported in the literature indicated that the surgical intervention for hydrocephalus resolves amenorrhea in all the cases of amenorrhea due to hydrocephalus. The suspected role of the surgery is the correction of increased intracranial pressure, which is an important pathogenetic factor in the development of amenorrhea.

Comparison of nitrophenylethyl and hydroxyphenacyl caging groups

Nitrophenylethyl (NPE)- and hydroxyphenacyl (HPA)-caged nucleotides were employed in a time-resolved Fourier transform IR spectroscopy study on Ras-catalyzed guanosine triphosphate (GTP) hydrolysis. A fast kinetic component was observed following the photolysis of NPE-caged nucleotides in the NPE-GTP-Ras complex. However, this kinetic component was not observed in the HPA-GTP-Ras experiment. This fast kinetic component was likely due to a chemical reaction between Ras and the detached caging group, nitrosoacetophenone. This communication serves as a note of caution in interpreting spectral changes and kinetic behavior of the enzymatic systems employing NPE-caged compounds.

Efficient induction of antigen-specific, T helper type 1-mediated immune responses by intramuscular injection with ovalbumin/interleukin-18 fusion DNA

The balance of two types of T helper (Th) cells, Th1 and Th2 subsets, is important with respect to susceptibility or resistance to particular infections, or to autoimmune diseases and allergic diseases. To effectively induce Th1 immune responses in an antigen-specific manner, we constructed a mammalian expression plasmid (pOVA/IL-18) carrying a fusion gene in which the ovalbumin (OVA; a model antigen) cDNA was covalently linked to mature interleukin-18 (IL-18) cDNA. Intramuscular injection of C57BL/6 mice with the pOVA/IL-18 DNA efficiently increased the production of both OVA-specific IFN-gamma and anti-OVA IgG2a isotype, compared with the injection with the pOVA DNA. In addition, the pOVA/IL-18 was more efficient than a simple mixture of pOVA and pIL-18 in inducing antigen-specific, Th1 immune responses and in inhibiting OVA-specific, IL-4 production. These studies indicate that vaccination with the OVA/IL-18 fusion DNA efficiently induces Th1 immune response in an antigen-specific manner.

BeF(3)(-) acts as a phosphate analog in proteins phosphorylated on aspartate: structure of a BeF(3)(-) complex with phosphoserine phosphatase

Protein phosphoaspartate bonds play a variety of roles. In response regulator proteins of two-component signal transduction systems, phosphorylation of an aspartate residue is coupled to a change from an inactive to an active conformation. In phosphatases and mutases of the haloacid dehalogenase (HAD) superfamily, phosphoaspartate serves as an intermediate in phosphotransfer reactions, and in P-type ATPases, also members of the HAD family, it serves in the conversion of chemical energy to ion gradients. In each case, lability of the phosphoaspartate linkage has hampered a detailed study of the phosphorylated form. For response regulators, this difficulty was recently overcome with a phosphate analog, BeF(3)(-), which yields persistent complexes with the active site aspartate of their receiver domains. We now extend the application of this analog to a HAD superfamily member by solving at 1.5-A resolution the x-ray crystal structure of the complex of BeF(3)(-) with phosphoserine phosphatase (PSP) from Methanococcus jannaschii. The structure is comparable to that of a phosphoenzyme intermediate: BeF(3)(-) is bound to Asp-11 with the tetrahedral geometry of a phosphoryl group, is coordinated to Mg(2+), and is bound to residues surrounding the active site that are conserved in the HAD superfamily. Comparison of the active sites of BeF(3)(-) x PSP and BeF(3)(-) x CeY, a receiver domain/response regulator, reveals striking similarities that provide insights into the function not only of PSP but also of P-type ATPases. Our results indicate that use of BeF(3)(-) for structural studies of proteins that form phosphoaspartate linkages will extend well beyond response regulators.

Cataract in leprosy patients: cataract surgical coverage, barriers to acceptance of surgery, and outcome of surgery in a population based survey in Korea

BACKGROUND/AIMS

Cataract is the leading cause of blindness in leprosy patients. There is no population based information on the cataract surgical coverage, barriers to use of surgical services, and outcome of surgery in these patients. We sought to determine these measures of cataract programme effectiveness in a cured leprosy population in South Korea.

METHODS

The population consisted of residents of six leprosy resettlement villages in central South Korea. All residents were invited to participate in a study of eye disease and interviewed regarding use of surgical services and reasons for not using these services.

RESULTS

The cataract surgical coverage in this population was 55.4% when <6/18 was used as the cut off and increased to 78.3% when the cut off was <6/60. Barriers reported by patients included being told by the doctor that the cataract was not mature and a perception by the patient that there was no need for surgery. Among patients who had aphakic surgery, 71% were still blind in the operative eye while among patients who had pseudophakic surgery, 14% were still blind (presenting vision). Blindness in pseudophakic patients could be reduced to 3% with spectacle correction.

CONCLUSION

Cataract prevalence in leprosy patients will increase as life expectancy continues to increase. Leprosy control programmes will need to develop activities aimed at reducing the burden of cataract. Recommendations include establishing collaborative agreements with ophthalmological services to provide high quality IOL surgery to these patients, training of health staff to identify and refer patients in need of surgery, monitoring the uptake of cataract surgery among patients needing services, and monitoring the outcome of surgery to improve refractive outcome.

Effective treatment of head and neck squamous cell carcinoma by an oncolytic herpes simplex virus

BACKGROUND

The prognosis of patients with advanced or recurrent head and neck squamous cell carcinoma remains poor despite refinements in multimodality therapies. This study evaluates the efficacy of a replication-competent, attenuated, oncolytic herpes simplex virus, NV1020, as a novel agent in the treatment of human head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Five different HNSCC lines were exposed to NV1020 in vitro at varying viral concentrations. The ability of the virus to lyse and replicate within these cancer cells in vitro was determined by cytotoxicity assay and plaque assay, respectively. Three HNSCC lines were grown in the subcutaneous flanks of athymic nude mice and treated with an intratumoral injection of NV1020 or saline as a control. Tumor dimensions were subsequently measured at serial time points and tumor volumes were calculated. Herpes simplex virus (HSV)-1 immunohistochemistry was performed on excised tumors to determine the efficacy of in vivo tumor infection by NV1020.

RESULTS

NV1020 was highly cytotoxic in vitro to all five human HNSCC lines at a concentration of one infectious viral particle per cancer cell, and had variable cytotoxicity at a 100-fold lower concentration. Viral replication in vitro by NV1020 was efficient in four of five HNSCC lines with a greater than 200-fold increase in viral titers. Flank tumors treated with intratumoral injections of NV1020 resulted in significant regression of all tested HNSCC lines. HSV-1 immunohistochemistry of excised flank tumors treated with NV1020 demonstrated positive cytoplasmic staining and areas of tumor necrosis at 24 hours after injection.

CONCLUSIONS

NV1020 is an oncolytic HSV that displays efficient replication and oncolysis in human HNSCC lines in vitro. Injection of NV1020 into murine flank tumors demonstrated effective tumor regression. Treatment of HNSCC with NV1020 is a promising form of therapy with potential clinical applicability in humans.