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Figure S1. (A) Cumulative incidence as a function of the maximum adaptive sampling population size. Dashed line represents the mean, and the dotted lines are the mean ± the standard deviation. (B) Epidemic time series for three different maximum adaptive sampling population sizes. Solid lines are means and shaded areas represent the range. Figures S2–S9. The joint distribution of parameter estimates for amount of rainfall-associated temporary larval mosquito habitat and the decay rate of that temporary habitat. Left panels are estimates from the single-patch departmental model, and right panels are estimated from the multi-patch departmental model. Each figure contains results from four departments, with the departments ordered from lowest to highest relative MASE as displayed in Fig. 2. Figures S10–S17. The joint distribution of parameter estimates for the timing of the initial importation event(s) and the magnitude of importation. Left panels are estimates from the single-patch departmental model, and right panels are estimated from the multi-patch departmental model. Each figure contains results from four departments, with the departments ordered from lowest to highest relative MASE as displayed in Fig. 2. Figures S18–S19. Comparisons of department-level results for single-patch and multi-patch models for three different symptomatic rates (0.54, 0.72, and 0.90). Black dots represent the observed time series, darker colored lines are the single best-fitting simulations, and lighter colored lines are the other 40 top simulations. (PDF 40161 kb)

Hybrid density functional theory (HDFT) and post Hartree–Fock CCSD(T) methods are applied to elucidate the binding energies and the optimized MO distances of transition metal oxides: MO (M = Cr, Mn, Fe, Co, Ni, Cu). The HDFT method can reproduce the CCSD(T) results, in agreement with the experimental ones. The nature of the manganese–oxygen bonds in the Mn(VI)O, Mn(IV)O porphyrin (PP), and Mn(V)O PP systems are examined in relation to possible mechanisms of oxygen evolution from H2O2 and H2O in native and non-native manganese complexes. It is found that the radical character of the high-valent (PP)Mn(V)O bond is remarkable, showing the strong potential to generate molecular oxygen because of its high reactivity. The electronic structure and magnetic property of μ-oxo-bridged manganese porphyrin dimer (PPMn(III)OMn(III)PP) are investigated for further discussion of structure and reactivity of PPMn(X)O (X = II–IV). The potential curve for release of molecular oxygen from PPMn(II)O2 is also examined to show weak affinity of O2 in the Mn complex where the oxidation number (X) of Mn is low. Implications of the computational results are also discussed in relation to oxygen evolution reactions. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004

Optical conductivity data of the intermetallic compounds (Fe1 - xVx)3Al (0 ? x ? 0.33) reveal that their density of states around the Fermi energy (EF) is strongly reduced as x is increased. In particular, Fe2VAl (x = 0.33) has a deep, well-developed pseudogap of 0.1-0.2 eV at EF and a small density (?5 × 1020 cm-3) of carriers, which is highly unusual for intermetallic compounds. It is shown that the pseudogap results from the band structure of Fe2VAl, rather than from temperature-dependent correlation effects. Based on the present results, we propose a simple model that consistently explains both the semiconductorlike transport and the metallic photoemission results previously observed for Fe2VAl.

D-Amino acid transaminase is a bacterial enzyme that uses pyridoxal phosphate (PLP) as a cofactor to catalyze the conversion of D-amino acids into their corresponding alpha-keto acids. This enzyme has already been established as a target for novel antibacterial agents through suicide inactivation by a number of compounds. To improve their potency and specificity, the detailed enzyme mechanism, especially the role of its PLP cofactor, is under investigation. Many PLP-dependent transaminases have a negatively charged amino acid residue forming a salt-bridge with the pyridine nitrogen of its cofactor that promotes its protonation to stabilize the formation of a ketimine intermediate, which is subsequently hydrolyzed in the normal transaminase reaction pathway. However, alanine racemase has a positively charged arginine held rigidly in place by an extensive hydrogen bond network that may destabilize the ketimine intermediate, and make it too short-lived for a transaminase type of hydrolysis to occur. To test this hypothesis, we changed Glu-177 into a titratable, positively charged lysine (E177K). The crystal structure of this mutant shows that the positive charge of the newly introduced lysine side chain points away from the nitrogen of the cofactor, which may be due to electrostatic repulsions not being overcome by a hydrogen bond network such as found in alanine racemase. This mutation makes the active site more accessible, as exemplified by both biochemical and crystallographic data: CD measurements indicated a change in the microenvironment of the protein, some SH groups become more easily titratable, and at pH 9.0 the PMP peak appeared around 315 nm rather than at 330 nm. The ability of this mutant to convert L-alanine into D-alanine increased about 10-fold compared to wild-type and to about the same extent as found with other active site mutants. On the other hand, the specific activity of the E177K mutant decreased more than 1000-fold compared to wild-type. Furthermore, titration with L-alanine resulted in the appearance of an enzyme-substrate quinonoid intermediate absorbing around 500 nm, which is not observed with usual substrates or with the wild-type enzyme in the presence of L-alanine. The results overall indicate the importance of charged amino acid side chains relative to the coenzyme to maintain high catalytic efficiency.

Inverse photoemission spectra (IPES) of a decagonal single quasicyrstal Al72Ni12Co16 have been measured for various incident electron energiesEi together with its AlL2,3 soft X-ray emission spectra (SXES). Both IPES and SXES show low intensity near the photon energy corresponding to the Fermi level, which is consistent with an opening of a pseudo-gap across the Fermi level. The IPES shows no strong resonance enhancement, suggesting apparently small density of the transition metald states above the Fermi level. However, constant final state spectra of the inverse photoemission reveal faint humps aroundEi = 62 and 76 eV, which might indicate resonances due to the Co and Ni3d-derived states, respectively. A shoulder structure at the low photon energy side of the main band in the AlL2,3 SXES becomes prominant for the lower incident electron energy and is tentatively ascribed to the Ni3p emission band.

An anomalous negative temperature dependence of electrical resistivity has been observed in (Fe1-xVx)3Al alloys with V compositions up to x = 0.35. In particular, the Heusler-type Fe2VAl compound is found to be on the verge of magnetic ordering and to exhibit a semiconductorlike behavior with the resistivity reaching 3000 μΩ cm at 2 K, in spite of the possession of a clear Fermi cutoff as revealed in photoemission valence-band spectra. A substantial mass enhancement deduced from specific heat measurements suggests that Fe2VAl is a possible candidate for a 3d heavy-fermion system.

To investigate the incidence of ocular complications in patients with rheumatoid arthritis under modern modalities of treatment and find the relationship between its systemic activity and ocular complications, routine ophthalmological examinations were done as a prospective study in 111 consecutive patients including 89 inpatients and 22 outpatients with rheumatoid arthritis seen from April to May 1995, in a hospital with a special clinic for rheumatology. Keratoconjunctivitis sicca (secondary Sjögren's syndrome) was found in 19 patients (17.1%), scleritis in one patient (0.9%), central retinal vein occlusion in 2 patients (1.8%), and idiopathic retinal hemorrhage in 3 patients (2.7%). Patients with keratoconjunctivitis sicca had significantly higher titers of rheumatoid factor (Mann-Whitney's U-test, p = 0.0048), higher levels of IgM (p = 0.0484), and lower levels of HDL-cholesterol (p = 0.0191), compared to patients without it. The incidence of ocular complications was comparable to the previous studies and keratoconjunctivitis sicca should be considered in patients with high titers of rheumatoid factor.

We have developed a new fine-caliber (2.09 mm outer diameter) endoscope for peroral cholangiopancreatoscopy. The endoscope contains one image transmission fiber, 12 light guide fibers (the transmitter of light from the light source) and a working channel (a lumen for the guide wire and rinsing). The working channel, whose bore is 0.72 mm, is located centrally within the endoscope. The endoscope can be introduced reliably into the bile and pancreatic ducts using the same techniques as those for endoscopic nasobiliary drainage through the instrumental channel of a duodenoscope for examination without pretreatment of the papilla of Vater. Two patients with lesions of the pancreatic duct and seven patients with lesions of the bile duct suspected or detected by endoscopic retrograde cholangiopancreatography (ERCP) were examined. Direct inspection of the biliopancreatic duct not only provided enough information to make a definite diagnosis, but also revealed lesions that were not detectable by ERCP or other examinations.

Leucine dehydrogenase has been purified to homogeneity from a moderate thermophilic actinomycete, Thermoactinomyces intermedius IFO 14230. The enzyme can be stored without loss of its activity at a low temperature (e.g., 4 degrees C) for over two years. The enzyme was more thermostable at higher concentrations of salts such as NaCl and KCl. It retained about 90% of activity on incubation at 70 degrees C for at least 40 min in the presence of 3 M NaCl. The Michaelis constants for NAD, L-leucine, NADH, 2-oxoisocaproate and ammonia were determined to be 0.36, 2.0, 0.042, 0.63 and 118 mM, respectively, from initial-velocity analyses. The enzyme showed pro-S stereospecificity for hydrogen transfer of NADH in the reductive amination. The enzyme gene was cloned into Escherichia coli and its complete DNA sequence was determined. The leucine dehydrogenase gene (leudh) consists of a 1098-bp open reading frame and encodes 366 amino acid residues corresponding to a subunit (M(r) 40586) of the octameric enzyme. The amino acid sequence of the enzyme showed 80.7% similarity with that of the Bacillus stearothermophilus enzyme. The enzyme was overproduced in E. coli JM 109 having a recombinant plasmid, pULDH2, which was constructed from pUC18 and the leudh gene. The enzyme was purified from the cell extract to homogeneity in one day, with 78% recovery.

We have cloned the thermostable alanine dehydrogenase gene from a thermophile, Bacillus stearothermophilus into Escherichia coli C600 with a vector plasmid pKK 223-3. The recombinant cells produced a large amount of the enzyme, which corresponded to about 10% of the total amount of cellular proteins. In order to prevent the cells from leaking to the environment, cell culture and disruption were consecutively carried out in the same fermentor equipped with a HEPA filter, which served as a biological barrier. The cells grown in the culture broth were treated with Triton X-100, lysozyme, and EDTA, whose final concentrations were 0.1%, 100 mg/ l , and 10 mM, respectively, for 30 min, followed by heating at 60°C for 30 min. Almost all of the enzyme (about 98%) was found in the broth, whereas no living recombinant cells were found in the broth, by these treatments. Based on these we established a large-scale production system of thermostable enzyme from recombinant cells.

The electronic structures of ZnTe and ${\mathrm{Zn}}_{0.7}$${\mathrm{Mn}}_{0.3}$Te have been investigated by means of synchrotron-radiation photoemission experiments. Te 4d core-yield spectra of ZnTe and ${\mathrm{Zn}}_{0.7}$${\mathrm{Mn}}_{0.3}$Te reflect the density of states (DOS) of the conduction bands. The two DOS peaks in the ZnTe spectrum observed at 0.6 and 4.3 eV above the conduction-band minimum are ascribed to relatively flat regions of the conduction bands near the ${\mathit{L}}_{1}$ and ${\mathit{X}}_{1}$, and the ${\mathrm{\ensuremath{\Gamma}}}_{15}$ and ${\mathit{L}}_{3}$, symmetry points, respectively. The contribution of the Mn 3d states to the valence bands of ${\mathrm{Zn}}_{0.7}$${\mathrm{Mn}}_{0.3}$Te has been evaluated by means of resonant enhancement of Mn 3d photoionization cross section near the Mn 3p-3d core excitation. The Mn 3d\char21{}derived partial DOS of ${\mathrm{Zn}}_{0.7}$${\mathrm{Mn}}_{0.3}$Te is found to be very similar to that of ${\mathrm{Cd}}_{0.8}$${\mathrm{Mn}}_{0.2}$Te. This suggests nearly equal Mn-Te bond lengths in these ternary alloys.

Thermal and stress analyses were performed using the finite element analysis code ABAQUS to clarify the factors which caused tears in the stainless steel liner of the reactor pressure vessel lower head of the Three Mile Island Unit 2 (TMI-2) reactor pressure vessel during the accident on 28 March 1979. The present analyses covered the events which occurred after approximately 20 tons of molten core material were relocated to the lower head of the reactor pressure vessel. They showed that the tensile stress was highest in the case where the relocated core material consisting of homogeneous UO2 debris was assumed to attack the lower head and the debris was then quenched. The peak tensile stress was in the vicinity of the welded zone of the penetration nozzle. This result agrees with the findings from the examination of the TMI-2 reactor pressure vessel that major tears in the stainless steel liner were observed around two penetration nozzles of the lower head.

An acoustic step-wave probing technique was used to investigate the electric field distribution in insulating materials subjected to a high DC electric stress. The acoustic step pressure was generated by applying a high-voltage step (rise time >

An enzymatic system for poly gamma-glutamate (PGA) synthesis in Bacillus subtilis, the PgsBCA system, was investigated. The gene-disruption experiment showed that the enzymatic system was the sole machinery of PGA synthesis in B. subtilis. We succeeded in achieving the enzymatic synthesis of elongated PGAs with the cell membrane of the Escherichia coli clone producing PgsBCA in the presence of ATP and D-glutamate. The enzyme preparation solubilized from the membrane with 8 mM Chaps catalyzed ADP-forming ATP hydrolysis only in the presence of glutamate; the D-enantiomer was the best cosubstrate, followed by the L-enantiomer. Each component of the system, PgsB, PgsC, and PgsA, was translated in vitro and the glutamate-dependent ATPase reaction was kinetically analyzed. The PGA synthetase complex, PgsBCA, was suggested to be an atypical amide ligase.

We investigated the total conversion of racemic lactate, L-lactate, and pyruvate into D-lactate, which is very useful as a starting material for the synthesis of chiral compounds and much more valuable than the L-enantiomer by means of coupling of L-specific oxidation of the racemate with L-lactate oxidase and non-enantiospecific reduction of pyruvate to DL-lactate with sodium borohydride. In this one-pot system, L-lactate was enantiospecifically oxidized to an achiral product, pyruvate, which was chemically reduced to DL-lactate leading to a turnover. Consequently, either DL-lactate, L-lactate, or pyruvate was fully converted to the D-enantiomer. We optimized the reaction conditions: DL-lactate was converted to D-lactate in 99% of the theoretical yield and with more than 99% enantiomeric excess. DL-alpha-Hydroxybutyrate and alpha-ketobutyrate were converted also to D-alpha-hydroxybutyrate in the same way, though slowly.

Vitamins are defined as essential organic micronutrients that are not synthesized by mammals. Coenzymes are defined as organic compounds with low molecular weight that are required to show enzyme activities by reversibly binding with their apoenzymes. Most of vitamins and coenzymes show various biofunctions besides their functions as vitamins and coenzymes. Accordingly, it is more appropriate to understand both as effective biofactors. Various retinoid derivatives synthesized bind to retinoid binding proteins to regulate gene expressions and show other biofunctions. Pyridoxal phosphate serves as an inhibitor of catepsins, and regulates the gene expression. Several novel built-in coenzymes such as topaquinone and lysyltyrosylquinone have been demonstrated in mammalian and microbial enzymes.

This study surveyed the sexual behaviour of commercial sex workers and their clients in an attempt to identify factors of transmission of STDs (including HIV/AIDS) and to control their epidemics in Cambodia and South-East Asia.Cross-sectional study.Trained questioners asked items of the questionnaires to each objective subject in December 1996. Data were analysed to show the descriptive status by risk group of each person.200 direct commercial sex workers, 220 indirect commercial sex workers, and 211 clients in Phnom Penh.Prostitution was widely accepted by both young males and females, and this was an easy way for young girls to obtain money. Although commercial sex workers and clients were knowledgeable about prevention methods against STDs, they seldom used condoms. Some commercial sex workers had been infected with STDs many times, and many of them incompletely treated the diseases by themselves. Social support from governmental and non-governmental organisation was poor.It is very important to support both commercial sex workers in practicing preventive methods against STDs and also visiting physicians when they notice symptoms of STDs. It is strongly recommended that not only governmental but also non-governmental organisations should be more active in this area.

To describe epidemiological features of HIV prevalence among female commercial sex workers (CSWs) in Cambodia, a cross-sectional study using a questionnaire study and serological tests was carried out from December 1997 to January 1998. We report the main results of the analyses of serological tests in this article.Two hundred ninety six CSWs working in Sisophon and Poi Pet, located in northwest Cambodia, Bantey Mean Chey province, were recruited for interview based on a questionnaire on sexual behavior, and serological tests. The blood samples were examined for HIV antibody, Chlamydia trachomatis IgG antibody, TPHA, Hepatitis B surface antigen, and Hepatitis B surface antibody. The relationship between HIV and the other STD's was analyzed by using logistic regression analysis.The HIV seroprevalence rate was 43.9% (130 out of 296). The seropositive rate of Chlamydia trachomatis IgG antibody (C.T.-IgG-Ab) was 73.3% (217 out of 296). Logistic regression analysis showed a significant association between C.T.-IgG-Ab positive and HIV prevalence. (Odds Ratio: 5.33; 95% Confidence Interval, 2.82-10.07).This study suggests that the existence of Chlamydia trachomatis is closely related with HIV prevalence among CSWs in Cambodia. Other STDs may also increase susceptibility to male-to-female sexual transmission of HIV. This suggests that appropriate prevention against STDs will be needed for the control of HIV prevalence in Cambodia.

The lysine residue binding with the cofactor pyridoxal 5'-phosphate (PLP) plays an important role in catalysis, such as in the transaldimination and abstraction of alpha-hydrogen from a substrate amino acid in PLP-dependent enzymes. We studied the role of Lys39 of alanine racemase (EC 5.1.1.1) from Bacillus stearothermophilus, the PLP-binding residue of the enzyme, by replacing it site-specifically with alanine and characterizing the resultant K39A mutant enzyme. The mutant enzyme turned out to be inherently inactive, but gained an activity as high as about 0.1% of that of the wild-type enzyme upon addition of 0.2 M methylamine. The amine-assisted activity of the mutant enzyme depended on the pKa values and molecular volumes of the alkylamines used. A strong kinetic isotope effect was observed when alpha-deuterated D-alanine was used as a substrate in the methylamine-assisted reaction, but little effect was observed using its antipode. In marked contrast, only L-enantiomer of alanine showed a solvent isotope effect in deuterium oxide in the methylamine-assisted reaction. These results suggest that methylamine serves as a base not only to abstract the alpha-hydrogen from D-alanine but also to transfer a proton from water to the alpha-position of the deprotonated (achiral) intermediate to form D-alanine. Therefore, the exogenous amine can be regarded as a functional group fully representing Lys39 of the wild-type enzyme. Lys39 of the wild-type enzyme probably acts as the base catalyst specific to the D-enantiomer of alanine. Another residue specific to the L-enantiomer in the wild-type enzyme is kept intact in the K39A mutant.

A strain of Bacillus sphaericus isolated from a local soil sample has been found to use beta,beta-dimethyl-DL-cysteine (DL-penicillamine) as the sole nitrogen source. Crude cell extract of the bacterium showed potent penicillamine-consuming activity only in the presence of NAD, which, however, was not used as an electron acceptor. Characterization of reaction products revealed that penicillamine was derivatized to a phosphoramide adduct with the ADP moiety of NAD, whereas the nicotinamide-ribose group was released and hydrolyzed spontaneously to ribose and nicotinamide. The phosphoramide product, ADP-penicillamine, caused potent product inhibition on the purified enzyme, and adenylate deaminase was found to be effective in converting the inhibitory product into inosine-diphosphate-penicillamine and thereby maintained the catalysis for several hours. The novel enzyme, termed as NAD:penicillamine ADP transferase, showed a single band on SDS-polyacrylamide gel electrophoresis with a mass of approximately 42 kDa. The native enzyme was monomeric. The enzyme showed high substrate specificity to NAD (Km = 13.0 mM) and L-penicillamine (Km = 6.5 mM); other nucleotides such as NADP, NAD(P)H, AMP, ADP, and ADP-ribose did not substitute for NAD, and L-valine, L-cysteine, L-homocysteine, L-cystine, L-leucine, and L-isoleucine did not serve as the substrate. Kinetic studies suggested an Ordered Bi Bi mechanism, with NAD as the first substrate to bind and ADP-L-penicillamine as the last product released. The novel NAD-dependent enzyme may catalyze the first step in penicillamine degradation in the strain of B. sphaericus.

This paper reviews atomic structures and binding energies of binary Au and Ag atoms adsorbed at the Si(111) surface which have been studied under thermal annealing and ion bombardment by major use of Rutherford Backscattering Spectroscopy (RBS) and transmission ion channeling with low energy electron diffraction (LEED) and Auger Electron Spectroscopy (AES). On iso-chronal annealing from 200 °C to 430 °C for 15 min, it is shown by LEED that the Ag/Si(111)-5×1-Au surface shows the √3×√3 structure on the initial annealing at 200 °C and the Ag/Si(111)-√3×√3-Au surface with Ag coverages above 0.6 ML shows the 2√3×2√3 structure on the initial annealing, which changes into the √21×√21R(±10.89°) structure and furthermore into the √3×√3 structure as the temperature rises. The atomic arrangements and binding strengths of Au and Ag at the 2√3×2√3-(Au, Ag) surface have been determined by ion impact desorption with 5 keV Ar+ ions and transmission ion channeling with 6 MeV Li ions. The double layered structure and the ...

This paper describes the exchange of deuterium in a tritium breeding ceramics, Li2ZrO3, for protium by exposure to air-vapor which has been studied by means of the elastic recoil detection technique with 1.7 MeV He+ ion beam. The ceramic specimen implanted up to saturation concentration at room temperature with 5 keV D2+ ions is exposed to normal air introduced into the vacuum chamber at room temperature. It is found that the retained number of D implanted decreases, while the retain number of H increases as the exposure time to normal air increases. The exchange behavior of D for H in Li2ZrO3 is compared with that in SrCe0.95Yb0.05O3−δ studied previously and the processes for hydrogen isotope exchange observed are discussed.

To study the relationship between dietary calcium intake and bone mineral density (BMD) among young Japanese females, we recruited 1298 females under 40 years living in Yokohama city for BMD measurement by Computed X-ray densitometer (CXD method) and dietary questionnaire. 1. The average of BMD was 2.75 mm/AI and was highest in the 35 to 39 year old group. 2. Calcium intake (Ca) and protein intake (Protein) were highest in 35 to 39 year old group. 3. BMD, Ca, and Protein were significantly higher in those who had regular dietary habits than those with irregular habits. 4. Among those who had lower Ca, (less than 600 mg per day), the amount of small fish consumed whole was negatively correlated with BMD (p = 0.035), and those with higher consumption of small fish than average had significantly (p = 0.018) lower BMD than those with lower small fish consumption adjusting for age and Ca and protein intake. These findings imply a possibility that small fish accompanied by higher salt intake may influence BMD adversely in this population by an interaction with calcium urinary excretion, which has been suggested by experimental and epidemiologic studies. Dietary composition of Ca may be important for prevention of osteoporosis.

Selenocysteine lyase (EC 4.4.1.16) exclusively decomposes selenocysteine to alanine and elemental selenium, whereas cysteine desulfurase (NIFS protein) of Azotobacter vinelandii acts indiscriminately on both cysteine and selenocysteine to produce elemental sulfur and selenium respectively, and alanine. These proteins exhibit some sequence homology. The Escherichia coli genome contains three genes with sequence homology to nifS. We have cloned the gene mapped at 63.4 min in the chromosome and have expressed, purified to homogeneity, and characterized the gene product. The enzyme comprises two identical subunits with 401 amino acid residues (Mr 43,238) and contains pyridoxal 5'-phosphate as a coenzyme. The enzyme catalyzes the removal of elemental sulfur and selenium atoms from L-cysteine, L-cystine, L-selenocysteine, and L-selenocystine to produce L-alanine. Because L-cysteine sulfinic acid was desulfinated to form L-alanine as the preferred substrate, we have named this new enzyme cysteine sulfinate desulfinase. Mutant enzymes having alanine substituted for each of the four cysteinyl residues (Cys-100, Cys-176, Cys-323, and Cys-358) were all active. Cys-358 corresponds to Cys-325 of A. vinelandii NIFS, which is conserved among all NIFS-like proteins and catalytically essential (Zheng, L., White, R. H., Cash, V. L., and Dean, D. R. (1994) Biochemistry 33, 4714-4720), is not required for cysteine sulfinate desulfinase. Thus, the enzyme is distinct from A. vinelandii NIFS in this respect.

In cooperation with the Chinese Academy of Preventive Medicine and Yunnan Province Provincial Office for AIDS Control and Prevention, we studied the current status of HIV infection intravenous drug users (IVDUs) and other high risk groups in Yunnan province of China. As of the end of 1995, 1,807 HIV cases were officially reported (Positive rate was 0.6%), of which 1,278 (77.9%) were IVDUs, and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili which borders on Myammar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women and blood donors were 0.2%, 0.07% and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, (1) the integration and coordination of such preventive strategies in cooperation with community health workers, (2) general health education for condom use promotion and (3) care of psychological vulnerable person such as IVDUs, should be developed.In cooperation with the Chinese Academy of Preventive Medicine and the Yunnan Provincial Office for AIDS Control and Prevention, the authors studied the current status of HIV infection among intravenous drug users (IVDUs) and other high-risk groups in Yunnan province, China. As of the end of 1995, 1807 HIV cases had been officially reported (positive rate was 0.6%), of which 1278 (77.9 %) were IVDUs and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili, which borders on Myanmar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women, and blood donors were 0.2%, 0.07%, and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with the HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, the integration and coordination of such preventive strategies in cooperation with community health workers, general health education for condom use promotion, and care of psychologically vulnerable people such as IVDUs should be developed.

We investigated the incidence of atopic dermatitis and related factors at infant physical examination at health centers. Subjects were 900 infants (290 four-month-old infants, 298 one-year and six month-old infants, 312 three-year-old infants) who participated in infant physical examinations in Kanazawa-ku, Yokohama City. Overall, we analyzed 696 infants whose mothers had cooperated with the survey by completing questionnaires during physical examinations, and who submitted to examination by consulting dermatologists. The incidence of atopic dermatitis was 11.6% in 4-month-old infants, 12.2% in 1.5-year-old infants, and 12.1% in 3-year-old infants. The following were found to be related to the atopic dermatitis of infants. 1. Family history of atopic dermatitis in their mothers and older siblings. 2. Mothers' limited diet during pregnancy (avoiding some food which are suspected allergens). 3. Past history of molluscum contagiosum. 4. The frequency of taking bath. While epidemiological surveys of atopic dermatitis have previously been performed, the criteria at each survey was not identical and results could not be compared precisely. In this survey, 1. Dermatologists specializing in atopic dermatitis performed examinations. 2. All diagnoses were made according to standardized criteria which are applied nationwide. 3. All subjects were from a specific region. Because of this approach, this survey provides important information that can form the basis of comparison for future epidemiological surveys of atopic dermatitis.

In December 1995 and March 1996, we visited institutes which were conducting epidemiological studied of HIV/AIDS in Cambodia, and obtained data for further collaborative study between Japan and Cambodia. Data included information on AIDS patients and HIV infected persons, and behavioral epidemiology of CSWs (Commercial Sex Workers). The cumulative reported number of AIDS patients and HIV infected persons in Cambodia was 86 and 2,536 cases respectively in 1995. The cause of infection was mostly heterosexual contact with very few cases from injecting drug use (IDU) and other causes. The seroprevalence rate of HIV antibody among donated blood rapidly increased from 0.08% in 1991 to 4.47% in 1995, and those among CSWs and pregnant women were 37.9% and 2.6%, respectively, in 1995. The average rate of condom use among CSWs was 66%, but the rate of usual usage was only 14%. These results indicate that the HIV/AIDS epidemic had spread rapidly through CSWs, that it had been spread among peoples in communities, and that usage of condoms among CSWs was insufficient in Cambodia. Without strong countermeasures against HIV/AIDS in this country, HIV/AIDS epidemic may spread significantly to not only peoples in this country but also those in neighbouring countries in the future.

Asp10 of L-2-haloacid dehalogenase from Pseudomonas sp. YL was proposed to act as a nucleophile to attack the alpha-carbon of L-2-haloalkanoic acids to form an ester intermediate, which is hydrolyzed by nucleophilic attack of a water molecule on the carbonyl carbon (Liu, J.-Q, Kurihara, T., Miyagi, M., Esaki, N., and Soda, K. (1995) J. Biol. Chem. 270, 18309-18312). We have found that the enzyme is paracatalytically inactivated by hydroxylamine in the presence of the substrates monochloroacetate and L-2-chloropropionate. Ion spray mass spectrometry demonstrated that the molecular mass of the enzyme inactivated by hydroxylamine during the dechlorination of monochloroacetate is about 74 Da greater than that of the native enzyme. To determine the increase of the molecular mass more precisely, we digested the inactivated enzyme with lysyl endopeptidase and measured the molecular masses of the peptide fragments. The molecular mass of the hexapeptide Gly6-Lys11 was shown to increase by 73 Da. Tandem mass spectrometric analysis of this peptide revealed that the increase is due to a modification of Asp10. When the enzyme was paracatalytically inactivated by hydroxylamine during the dechlorination of L-2-chloropropionate, the molecular mass of the hexapeptide was 87 Da higher. Hydroxylamine is proposed to attack the carbonyl carbon of the ester intermediate and form a stable aspartate beta-hydroxamate carboxyalkyl ester residue in the inactivated enzyme.

L-2-Haloacid dehalogenase catalyzes the hydrolytic dehalogenation of L-2-haloalkanoic acids to yield the corresponding D-2-hydroxyalkanoic acids. The crystal structure of the homodimeric enzyme from Pseudomonas sp. YL has been determined by a multiple isomorphous replacement method and refined at 2.5 A resolution to a crystallographic R-factor of 19.5%. The subunit consists of two structurally distinct domains: the core domain and the subdomain. The core domain has an alpha/beta structure formed by a six-stranded parallel beta-sheet flanked by five alpha-helices. The subdomain inserted into the core domain has a four helix bundle structure providing the greater part of the interface for dimer formation. There is an active site cavity between the domains. An experimentally identified nucleophilic residue, Asp-10, is located on a loop following the amino-terminal beta-strand in the core domain, and other functional residues, Thr-14, Arg-41, Ser-118, Lys-151, Tyr-157, Ser-175, Asn-177, and Asp-180, detected by a site-directed mutagenesis experiment, are arranged around the nucleophile in the active site. Although the enzyme is an alpha/beta-type hydrolase, it does not belong to the alpha/beta hydrolase fold family, from the viewpoint of the topological feature and the position of the nucleophile.

During early Meiji era in Japan, there were frequent epidemics of fatal acute communicable diseases such as cholera, dysentery and smallpox, and preventive measures and preparations for acute infectious diseases were urgently needed. Together with improvement of scientific preparations, the Communicable Disease Prevention Law was promulgated in 1897. Then gradually until 1940's, the focus of preventive measures have been shifted from acute infectious diseases to chronic ones, particularly tuberculosis. After the World War II, except the short period of social confusion, major legally-defined communicable diseases had been decreasing rapidly mainly due to the use of antibiotics and improvement of environmental sanitation. At the same time, the introduction of preventive vaccination marked a new era for the prevention of infectious diseases and was largely responsible for the remarkable decrease of infant mortality in Japan. Recently the concept of defense by vaccination against infectious diseases has evolved from group-oriented to individual-oriented, so that the Preventive Vaccination Law was drastically revised in 1994. Currently, effective counter-measures against newly emerged infectious diseases, as viral hepatitis, institution-acquired infection, viral hemorrhagic fever etc., have been implemented. For the future, improvement of infections disease surveillance, vaccine development and expansion of vaccination coverage along with monitoring side-effects, preventive health education on AIDS/STDs, addressing the special needs of foreigners living in Japan and international collaboration for disease control abroad are all vital to the success of protection of the public's health from infectious diseases in Japan.

The data obtained from the national reporting system of acquired immune deficiency syndrome (AIDS) and its causative immune deficiency virus (HIV), the epidemic pattern of AIDS cases and HIV carriers in Japan from 1985 to 1995 could be summarized as follows: 1) the total number of reported AIDS cases and HIV carriers were 1,154 and 3,524 which included 167 and 915 foreigners, respectively; 2) among them the number of HIV carriers in hemophiliacs transmitted through HIV contaminated blood products was 1,806, including 582 AIDS victims; 3) excluding these hemophiliacs, there are 572 AIDS cases (167 foreigners) which shared risk factors for heterosexual contacts (37%) and homosexual contacts (31%), respectively; 4) on the other hand, more than 50% were heterosexuals and only 20% were homosexuals in 1,718 HIV carriers (915 foreigners); 5) the peak incidence is 33% in the 30s in AIDS, while more than 50% are in their 20s; 6) male-to-female ratio was 6.8 in AIDS cases but only 1.1 in HIV carriers; 7) the estimated number of HIV carriers in 2000 was 6,300-8,500 in Japanese and 700-1,700 in foreigners, respectively. From the above mentioned epidemic pattern of AIDS/HIV in Japan, we have to recognize that the recent number of HIV infection is actually increasing and the most of current HIV carriers even in foreigners are infected with HIV in our country and general activities for AIDS prevention in Japan and neighboring Asian countries should be promoted.

The dimeric L-2-haloacid dehalogenase from Pseudomonas sp. YL, (subunit mass, 26179 Da), has been crystallized by vapor diffusion, supplemented by repetitive seeding, against a 50 mM potassium dihydrogenphosphate solution (pH 4.5) containing 15% (w/v) polyethylene glycol 8,000 and 1% (v/v) n-propanol. The crystals belong to the monoclinic space group C2 with unit cell dimensions of a = 92.21 angstrom, b = 62.78 angstrom, c = 50.84 angstrom, and beta = 122.4 degrees, and contain two dehalogenase dimers in the unit cell. They are of good quality and diffract up to 1.5 angstrom resolution.

We here describe activation mechanisms of three characteristic metalloenzymes by metals. The copper-containing amine oxidase contains a topaquinone residue at the active site. The inactive precursor form of the enzyme, which contains a tyrosine residue at the position corresponding to topaquinone of the matured protein, was isolated and converted to the matured form by incubation with cupric ions through self-processing of the protein. The selenocysteine residue of selenium-containing formate dehydrogenase is synthesized cotranslationally through a process directed by a UGA codon that normally functions as a stop codon. We describe the mechanism of recognition of UGA and specific incorporation of selenium into the protein. Vanadium-containing haloperoxidases afford stable apo forms lacking vanadium. Reconstitution of holo forms by vanadium ions are also described.