Daidzein reductase of Eggerthella sp. YY7918, its octameric subunit structure containing FMN/FAD/4Fe-4S, and its enantioselective production of R-dihydroisoflavones

S-Equol is a metabolite of daidzein, a type of soy isoflavone, and three reductases are involved in the conversion of daidzein by specific intestinal bacteria. S-Equol is thought to prevent hormone-dependent diseases. We previously identified the equol producing gene cluster (eqlABC) of Eggerthella sp. YY7918. Daidzein reductase (DZNR), encoded by eqlA, catalyzes the reduction of daidzein to dihydrodaidzein (the first step of equol synthesis), which was confirmed using a recombinant enzyme produced in Escherichia coli. Here, we purified recombinant DZNR to homogeneity and analyzed its enzymological properties. DZNR contained FMN, FAD, and one 4Fe-4S cluster per 70-kDa subunit as enzymatic cofactors. DZNR reduced the CC bond between the C-2 and C-3 positions of daidzein, genistein, glycitein, and formononetin in the presence of NADPH. R-Dihydrodaidzein and R-dihydrogenistein were highly stereo-selectively produced from daidzein and genistein. The K_m and k_cat for daidzein were 11.9 μM and 6.7 s^-1, and these values for genistein were 74.1 μM and 28.3 s^-1, respectively. This enzyme showed similar kinetic parameters and wide substrate specificity for isoflavone molecules. Thus, this enzyme appears to be an isoflavone reductase. Gel filtration chromatography and chemical cross-linking analysis of the active form of DZNR suggested that the enzyme consists of an octameric subunit structure. We confirmed this by small-angle X-ray scattering and transmission electron microscopy at a magnification of ×200,000. DZNR formed a globular four-petal cloverleaf structure with a central vertical hole. The maximum particle size was 173 Å.

Effect of High-Pressure Processing on Human Noroviruses in Laboratory-Contaminated Oysters by Bio-Accumulation

The contamination of oysters with human noroviruses poses a human health risk, since oysters are often consumed raw. In this study, human norovirus genogroup II was allowed to bio-accumulate in oysters, and then the effect of high-pressure processing (HPP) on human noroviruses in oysters was determined through a polymerase chain reaction (PCR)-based method with enzymatic pretreatment to distinguish infectious noroviruses. As a result, oysters could be artificially contaminated to a detectable level of norovirus genome by the reverse transcription-PCR. Concentrations of norovirus genome in laboratory-contaminated oysters were log normally distributed, as determined by the real-time PCR, suggesting that artificial contamination by bio-accumulation was successful. In two independent HPP trials, a 1.87 log₁₀ and 1.99 log₁₀ reduction of norovirus GII.17 genome concentration was observed after HPP at 400 MPa for 5 min at 25°C. These data suggest that HPP is a promising process of inactivation of infectious human noroviruses in oysters. To our knowledge, this is the first report to investigate the effect of HPP on laboratory-contaminated noroviruses in oysters.

Application of next-generation sequencing to investigation of norovirus diversity in shellfish collected from two coastal sites in Japan from 2013 to 2014

A better understanding of the role played by shellfish regarding the manner of pathogen contamination, persistence, and selection may help considering epidemiology of noroviruses. Thus, norovirus genotype profiles in shellfish (Crassostrea gigas and Mitilus galloprovincialis) were investigated by using Next-generation sequencing (NGS) technology. In genogroup I (GI), 7 genotypes (abbreviated as GI.2 to GI.7, and GI.9) were detected from C. gigas, whereas 9 genotypes (GI.1 to GI.9) were detected from M. galloprovincialis. The genotype with the highest proportion found in both C. gigas and M. galloprovincialis was GI.4, and the second highest was GI.3. In genogroup II (GII), 17 genotypes (GII.1 to GII.9, GII.11 to GII.17, GII.21 and GI.22) were detected from C. gigas, whereas 16 genotypes (GII.1 to GII.8, GII.11 to GII.17, GII.21 and GI.22) were detected from M. galloprovincialis. The genotype with the highest proportion in both C. gigas and M. galloprovincialis was GII.4, the next highest differed between C. gigas and M. galloprovincialis. To our knowledge, this study may be the first trial to utilize the latest technology in this field, and reveal the diversity of norovirus genotypes present in shellfish.

Effect of stress ratio on the fatigue behaviour of compact bone

During the fatigue process of bone, cracks generally initiate from the inherent defects existing in the bone. The fatigue lives of bone specimens at different stress levels as well as at different stress ratios R were evaluated using a computer simulation in which the crack propagation behaviour initiated from the inherent defects in the bone are herein considered. The S-N curves as well as the distributions of fatigue lives obtained by the simulations accurately conform with the experimental results. With the strain threshold epsilon(max) representing fatigue failure of the bone specimen, the values of 1500 microepsilon for R = -1, 2500 microepsilon for R = 0.1 and 4000 microepsilon for R = 10 were extrapolated from the simulations. These values conform with experimental values reported in the literature. Such conformity indicates that the strain threshold for fatigue failure is associated with the threshold value for crack propagation.

The static and cyclic strength of a bone-cement bond

Four-point bending static and fatigue tests were carried out on bone-cement bonds. The effects of the pressurization and the washing of the bone joint face on the bond strength were investigated. The results are summarized as follows. When the bond surface of cancellous bone is washed prior to the application of the bone cement, both the static and fatigue strengths of the bond are increased relative to the corresponding properties of unwashed bone-cement bonds. From observations of bone-cement interfaces as well as the fracture surfaces of bone-cement specimens, it has been determined that bone cement was able to infiltrate into fine holes present in washed cancellous bone. However, such infiltration occurred to a much lesser degree in the case of unwashed cancellous bone. Increasing the molding pressure during the time of cement application to the bone from 39200 to 117600 Pa had a beneficial effect on the bending strength and fatigue properties, particularly in the case of washed bone cement specimens. An increase in molding pressure also resulted in a reduction in the amount of scatter in test results.

On fatigue lifetimes and fatigue crack growth behavior of bone cement

Bone cement is used to develop a mechanical bond between an artificial joint and the adjacent bone tissue, and any degradation of this bond is of serious concern since it can lead to loosening and eventually malfunction of the artificial joint. In the present study, the fatigue lives and fatigue crack propagation behavior of two bone cements, CMW Type 3 and Zimmer, were investigated, and it was found that the size and distribution of pores played a major role in influencing both the fatigue crack initiation and propagation processes. The fatigue lifetimes of CMW exceeded those of Zimmer because of a lesser density of large pores. When the fatigue lifetimes were plotted as a function of Klimax, the maximum initial stress intensity factor based upon the initiating pore size, the difference in fatigue lifetimes between CMW and Zimmer bone cements was greatly reduced. The fatigue crack growth behavior of both bone cements were similar. This is a further indication that the noted differences in fatigue lifetimes were related to the size of the pore at the crack initiating site.

[Population pharmacokinetic analysis of theophylline: relationship between serum concentrations and clinical effects in therapeutic drug monitoring]

Therapeutic drug monitoring (TDM) of theophylline is essential duties at hospital pharmacy in Japan. The relationship between serum concentrations and clinical effects of theophylline has been investigated. The pharmacokinetics of theophylline was determined from the concentration of theophylline in the serum which were calculated on the basis of TDM for patients administered theophylline. The one-compartment model as a pharmacokinetic model was assumed. The relationship between clinical effects of theophylline and the predicted concentrations calculated using population parameters was evaluated. The obtained parameters are ka(h-1) = 0.223, ke(h-1) = 0.047 (1-0.0025.age(y) (p.o.) and 0.076(1-0.0025.age(y)) (d.i.v.), Vd(1/kg) = 0.733 (p.o.) and 0.830 (d.i.v.). The bioavailability is 0.732, and theophylline/aminophylline is 0.846. The model including no serum creatinine as a variational factor was considered to be best. The following three groups were used as a clinical evaluation; effective as theophylline therapy was 43%, no change of the clinical status after administration of theophylline was 42%, and aggravation after administration of theophylline was 15%. There is no relationship between the predicted concentration using parameters of the final model and these three groups. These results suggest that TDM of theophylline should be assessed in terms of clinical effects and also suggests that in should be kept monitoring from the viewpoint of the prevention of toxic effects in the theophylline therapy.

[Induction of protective immunity for Bordetella pertussis by nasal inoculation of pertussis vaccine in mice]

Although nasal vaccination has emerged as an interesting alternative to intramuscular or oral vaccination, knowledge is scarce about the immune responses after such immunization. In the present study, we inoculated purified Pertussis Toxin (PT) and Filamentous Haemagglutinin (FHA) with or without adjuvant (kayexalate), or Diphtheria acellular Pertussis Tetanus (DaPT) combined vaccine to mice intranasally three times every four weeks to investigate the references of the immunoresponses between nasal and intramuscular vaccination. The levels of pertussis specific serum IgG antibodies (Abs) and secretory IgA Abs in the nasal wash were measured by ELISA, and cytotoxic T cell activities were examined by proliferative response, and compared with the result from intramuscular inoculation. We also studied the efficacy of adjuvant in the nasal vaccination. The intramuscular inoculation of pertussis vaccine induced serum IgG antibodies and cellular immunity against PT and FHA, but did not induce local IgA antibodies. On the other hand, the nasal inoculation induced both serum and local antibody responses. Moreover, it also induced significant cellular immunity to pertussis antigen. In nasal vaccination, the inoculation with adjuvant was superior to inoculation without adjuvant for the induction of both humoral and cellular immunity.

Evidence for the archaebacterial-type conformation about the bond between the beta-ionone ring and the polyene chain of the chromophore retinal in chlamyrhodopsin

Previous studies using retinal analogs (Wada, A., Sakai, M., Kinumi, T., Tsujimoto, K., Yamauchi, M. and Ito, M. (1994) J. Org. Chem. 59, 6992-6997; Wada, A., Sakai, M., Imamoto, Y., Shichida., Y., Yoshizawa, T. and Ito, M. (1993) Chem. Pharm. Bull. 41, 793-795) revealed that both retinochrome and visual pigments share a common chromophoric conformation in which the ring region of retinal is twisted ca. 50 degrees with respect to the plane of the polyene chain, suggesting a highly conserved 6-s-cis conformation throughout rhodopsin-like pigments in animals. By contrast, 6-s-trans conformation was commonly observed or suggested in archaebacterial rhodopsins examined thus far. Here we have reconstituted in vivo both the photoreceptor for photobehavioral responses of the unicellular alga Chlamydomonas reinhardtii and the second archaeal sensory photoreceptor phoborhodopsin from a series of retinal analogs. Results exclusively point to the conclusion that in both photoreceptors retinal has the coplanar 6-s-trans conformation, though recent molecular cloning studies revealed no homology between Chlamydomonas photoreceptor (chlamyrhodopsin) and archaeal rhodopsins.

Determination of 6s-trans conformation of retinal chromophore in sensory rhodopsin I and phoborhodopsin

8,16-Ethanoretinal 3 was synthesized from 2-methylcyclohexanone. From the binding experiments of 3 and 8,18-ethanoretinal 2 with apoproteins of sensory rhodopsin I and phoborhodopsin, it was found that retinal was incorporated as 6s-trans conformation in the both proteins.

[Clinical and bacteriological studies on panipenem/betamipron in pediatrics. Kanagawa Research Group for Infectious Diseases of Children]

Following its introduction into the market, PAPM/BP (panipenem/betamipron) was clinically studied in 188 evaluable cases out of 207 cases primarily of respiratory infectious diseases treated at the pediatric departments of 15 hospitals. In the clinical evaluation, the drug proved effective in three of three cases of sepsis; three of three cases of suppurative meningitis; nine of ten cases of laryngopharyngitis, six of seven cases of tonsillitis, 56 of 63 cases of acute bronchitis, 90 of 98 cases of pneumonia, and one of one case of phyothorax, all of which are respiratory infectious diseases; one of one case of secondary infection of a chronic respiratory disease; and two of two cases of lymphadenitis, which is a disease of the soft dermal structure. The overall efficacy rate was 91.0% (171/188 cases). In the bacteriological study, Gram-positive bacteria were eliminated in five of five strains of S. aureus, 30 of 31 strains of S. pneumoniae (96.8%), and three of three strains of S. pyogenes. Gramnegative bacteria were eliminated in 15 of 17 strains of H. influenzae (88.2%), three of four strains of M. catarrhalis, and two of two strains of K. pneumoniae. The overall elimination rate was 92.1% (70/76 strains). In the 23 strains of S. pneumoniae that were examined, penicillin-resistant strains accounted for 56.5%, showing an elimination rate of 100%. No serious adverse effects were observed, and the incidence of adverse effects was 1.45%. As for abnormalities in laboratory tests, levels of GOT and GPT increased in eight cases (3.88%), LDH increased in one case (0.48%), and neutropenia occurred in one case (0.51%). These results suggest that PAMP/BP could be considered the first choice in the treatment of infectious diseases in pediatrics, due to its effectiveness and high level of safety.

[Clinical evaluation of faropenem against infections in pediatric fields]

The recent increases in the prevalence of penicillin-resistant Streptococcus pneumoniae becomes a point at issue clinically. We carried out a clinical study in 40 cases in the pediatrics department, as faropenem (FRPM) was proved to have an excellent antimicrobial activity against penicillin-resistant Streptococcus pneumoniae. The study was planned to investigate in detail the movement of stools that had been a problem in a clinical development studies out before. In this study, an observation of the daily movement of stools was one of the principal evaluation items, hence the patients were divided into two groups. One group (S-group) were administered FRPM only, the other group (E-group) were administered FRPM in combination with a medicine for intestinal disorders (Enteronon-R). An observed frequencies of any loose bowel movements were 94.7% in S-group, and 63.2% in E-group, hence the study suggested that the combination drug was effective. The patients observed higher frequencies of development of the movement of stools, all of them were recovered from in the course of administration or within 4 days after administration, however whether or not being treated symptomatic therapy. Clinical efficacy rates of FRPM on mainly respiratory infections were 94.6%. In this study, 4 strains (patients) of penicillin-resistant Streptococcus pneumoniae were isolated. Against penicillin-resistant Streptococcus pneumoniae, FRPM demonstrated more potent antibacterial activity than the oral penicillins and cephems tested here except cefditoren. Clinical efficacies was deemed effective in all of the 4 cases, and bacteriologically, 3 organisms were eradicated. As for side effects including diarrhea and loose stool, no serious side effects were observed. Based on the above results, FRPM is effective against most infections in the pediatric field which Streptococcus pneumoniae are isolated at high frequencies highly, and is considered to cases in be useful an attention will have to be paid to stool movement, however.

A comparison of young and aged populations for the diphtheria and tetanus antitoxin titers in Japan

The antitoxin levels for diphtheria and tetanus were measured with samples of a young group immunized with diphtheria-tetanus-acellular pertussis combined vaccine and those of an aged group, members of which had not received vaccination in their youth. In the young group members of which had already received basic immunization with diphtheria-tetanus-acellular pertussis combined vaccine, the levels of both antitoxins rose well after injection at 11 to 12 years old with diphtheria-tetanus combined toxoids and remained high until 20 years of age. In the aged group, more than 80% showed antitoxin levels above 0.01 u/ml for diphtheria, while all had levels below that for tetanus, except three persons with confirmed tetanus immunization history. Maintenance of the protective antitoxin levels in the population by vaccination is necessary to prevent outbreaks of infection among unvaccinated or only partially immunized persons.

[Investigation for VP4 region of coxsackie virus A16 RNA sequence from hand-foot-mouth disease patients at eastern district of Shizuoka prefecture in 1995]

In 1995 an investigation was made for VP4 regions of coxsackie virus A16 (CA16) RNA sequence from hand-foot-mouth disease patients in eastern district of Shizuoka Prefecture. Subjects were seven patients who were diagnosed as hand-foot-mouth disease due to CA16 at the Ohashi Pediatric Clinic in Susono City. Throat swabs of patients were extracted to RNA. Extracted RNA were assayed by reverse transcription polymerase chain reaction that primers corresponded to VP4 resion of enteroviruses. PCR products were marked by dye-deoxy terminator methods and assayed by direct sequence methods. RNA sequences were classified into two types. Type 1 were three cases, and type 2 were four. The homology was 90.8% between type 1 and type 2. All cases of sixty-nine amino acids were the same as prototype strain. We concluded that the two type strains of CA16 were prevalented in eastern district of Shizuoka Prefecture in 1995. It was at the same time and was widely noted in the eastern district.

[A case of neonatal herpes infection which proved to be a mixed infection of herpes simplex virus type 1 and type 2]

We encountered a case which proved to be a mixed infection of herpes simplex virus (HSV) type 1 and type 2 in retrospective terms by in situ hybridization (ISH) and polymerase chain reaction (PCR). The case was a male. The gestational age was 39 weeks and 2 days. The birth body weight was 3024 g. A fever developed from the age of 6 days and he was admitted to the neonatal intensive care unit at the age of eight days. AST was 1042 IU/L, and ALT 206 IU/L. In spite of treatment, the patient died at the age of 12 days. Using paraffin embedded tissues, we performed the ISH and PCR on the cerebrum, lungs, liver, spleen, bone marrow, adrenal gland, and kidneys. With the ISH, the lungs, liver, spleen and adrenal gland were both HSV type 1 and type 2. With the PCR, only the liver was positive for type 1, and the lungs, liver, spleen, and adrenal gland were positive for type 2. In the ISH, a probe showing a cross reaction between type 1 and type 2 was used for type 1 probe this time. But a type 2 probe and PCR did not show a cross reaction. We concluded that this case confirmed the presence of mixed infection (HSV type 1 and type 2) in neonatal HSV infection.

Sensitometric response of the Sens-A-Ray, a charge-coupled imaging device, to changes in beam energy

OBJECTIVES

To evaluate image density (pixel values) and image contrast due to variations in beam energy (kVp) for the Sens-A-Ray intra-oral radiographic sensor.

METHOD

Images of an aluminium step wedge were made at 50, 70 and 90 kVp. Mean pixel values (with standard deviations) for representative attenuator thicknesses were measured using region-of-interest histogram analysis. Corresponding entrance doses were measured using a beryllium-windowed ionization chamber.

RESULTS

The steepest response slopes were found with the lowest kVp settings; hence the CCD results mimic the behaviour of standard radiographic film, with the high contrast being found with low kVp. The entrance dose resulting in pixel saturation was less with low kVp than high kVp. It is suggested that this is due to the CCD receptor being most sensitive to X-ray photons of relatively low keV.

CONCLUSION

While the kVp needs to be selected in relation to both tissue and receptor characteristics, it is possible to use low kVp techniques with the Sens-A-Ray without increasing the entrance dosage.

Relation between serum hepatitis C virus-RNA levels and efficacy of interferon-beta therapy

We performed two courses of interferon-beta (IFN-beta) to a child with chronic hepatitis C. A complete response was not obtained by the first interferon treatment, however, the results of the second treatment differed from those of the first. Hepatitis C virus (HCV)-RNA remained negative and both aspartate aminotransferase and alanine aminotransferase levels remained normal after completion of the second course. From these results we estimated that HCV-RNA levels before IFN therapy could be significantly associated with the efficacy of this treatment. The serum level of HCV-RNA was 10(6) copies/50 microL before the first treatment, but was 10(3) copies/50 microL before the second course. We conclude that IFN therapy to children with hepatitis C should always be directed at providing a cure. Even if the clinical effects of the first course are minimal decreasing quantities of HCV-RNA still offer hope for cure by subsequent readministration.

[Familial clustering case of hepatitis delta]

We report a familial clustering case of hepatitis delta. All of the members of this family had evidence of past infection of hepatitis B. We investigated the hepatitis delta, three of the members had positive serological hepatitis delta markers. We assayed by polymerase chain reaction the primers corresponding to hepatitis delta antigen. The results of polymerase chain reaction was three positive. The 2nd polymerase chain reaction was used, two geno-type specific primers one was for Japanese S type the other was for Japanese M type7). Three were positive the 2nd polymerase chain reaction for Japanese M, one was negative for all of hepatitis delta polymerase chain reaction.

[A case of hepatoblastoma using intraarterial hepatic chemotherapy with THP-ADR]

The patient was a 2-year-old who was admitted with the diagnosis of liver tumor. The diagnosis at admission was stage III A hepatoblastoma complicated with tumor thrombosis of portal vein. Soon after the admission, the patient's general condition became deteriorated with increased ascites and severer jaundice. As the patient was considered to be in oncogenic emergency, chemotherapy with systemic administration of ADR and CDDP was started. Despite decreases in tumor marker and tumor shrinkage on imaging examinations, tachycardia and arrythmia occurred from the end of the second course of chemotherapy, suggesting ADR-induced cardiomyopathy, when the systemic administration of ADR was switched to less cardiotoxic hepatic arterial infusion of THP-ADR. Following 13 courses of intra-arterial infusion with the total dose of THP-ADR of 200 mg/m2, the tumor was found to have reduced markably in size and thus surgical resection of the tumor was performed. Our experience of this case indicates that, considering the pharmacokinetics and side effects, THP-ADR should be a very effective anti-tumor agent for intra-arterial hepatic infusion. The patient died 10 months after surgery because of multiple metastases into the brain and lungs.

Recovery of silver from radiographic fixer

This study examined the silver content of 10 brands of dental x-ray film that are commercially available in Japan. Kodak Ektaspeed EP-22 (Eastman Kodak Co., Rochester, N.Y.) was found to have the highest silver content, and SD 100 Gold X-ray Film (San Dental Co., Ltd., Tokyo, Japan) had the lowest content of silver. Electrolysis and ion exchange were used as the methods of silver recovery from films in the general dental office. Ion exchange was more than 99% efficient in silver recovery from the radiographic fixer and resulted in an 80% reduction in biochemical oxygen demand and a 95% reduction in chemical oxygen demand. However, these levels and other environmental pollutants were still above the limits set by the Japanese Pollutant Control law.

[Evaluation of vaccination for geriatric patients]

This paper evaluates the immune responses of geriatric patients to three vaccines; Japanese Encephalitis vaccine, inactivated Influenza vaccine and cold-adapted live Influenza vaccine. To evaluate the immune response, serum antibodies and lymphocyte phenotypes were measured of all three vaccines. In addition, nasal specific IgA antibodies were measured of the cold-adapted live Influenza vaccine. In the case of Japanese Encephalitis vaccine and the inactivated Influenza vaccine patients were inoculated subcutaneously with a 0.5 ml dose of the vaccine respectively. While with the cold-adapted vaccine, the doses were administered via spray into the bilateral nasal canals in 0.25 ml doses respectively. Measurements were taken both prior to and four weeks after the inoculations. In all the cases, sera were measured utilizing the hemagglutination inhibition (HI) method. Peripheral lymphocyte phenotypes were also measured utilizing the flow cytometry. In the case of the cold-adapted live influenza vaccine, nasal specific IgA antibodies were measured by the ELISA method. The results were as follows in all three cases: 1. Recipients who showed elevated HI antibody titers of more than 4 folds were 27.7% to 85.0%. 2. Peripheral lymphocyte phenotypes in geriatric patients were the same as the young control group both before and after inoculation. 3. Antibodies to the inactivated Influenza vaccine were maintained at high levels up to three months after inoculation. 4. The significant increased specific IgA antibodies were 50%. In conclusion, this suggests that inoculation of geriatric patients with the above vaccines is both safe and effective.

[Detection of antibody to varicella zoster virus by immune adherence hemagglutination]

Anti varicella-zoster virus (VZV) antibodies were detected by an immune adherence hemagglutination (IAHA) test, and were compared with the CF test, IFA test and ELISA test, respectively. Type O, Rh-positive RBC for IAHA was obtained from five healthy volunteers. All five RBCs had sufficient sensitivity as the indicator cell. Optimum incubation temperature was 37 degrees C in the serum and in the complement. The complement was obtained from guinea pig sera, and the most suitable concentration was 1;100. The convalescent VZV antibody titers were similar to the values obtained from any of the methods previously mentioned. However, mean titers measured by CF were about two-to fourfold lower than in the values of IAHA. Seroconversion rates of the live VZV vaccine, as detected by CF and IFA were relatively low (CF; 76%, IFA; 56%). In contrast, those obtained from ELISA and IAHA showed perfectly (100%). These results indicate that IAHA has sufficient sensitivity and specificity in the detection of VZV antibodies. In addition, the IAHA test is thought to be a rapid and easy test to perform in ordinary laboratories.

Evaluation of radiopaque denture liner

Radiopacity is needed in polymeric biomaterials to facilitate noninvasive detection. Permanent denture liner material with barium sulfate filler is nearly as radiopaque as aluminum and would be useful in radiographic identification. If 1 mm to 3 mm thicknesses are used, it should be easily observable radiographically.

Optimum radiopacity of composite inlay materials and cements

This study evaluated the radiopacity of recently introduced post-cured composite resin inlays and the composite dual-cure resin cements. Composite cement used as a luting material should have a minimal radiopacity of at least the same thickness as aluminum, to help in accurate radiologic discrimination.

Radiographic detection of recurrent carious lesions associated with composite restorations

The greatest potential problem associated with posterior composite restoration is secondary caries detection. It is essential that secondary caries is detected as early as possible to enhance the prognosis for a successful treatment outcome. This laboratory study evaluated the optimum level of radiopacity of composite materials for radiographic detection of secondary carious lesions associated with composite materials. Results indicated that for the radiologic detection of secondary caries, it is sufficient for composite materials to have the same level of radiopacity as enamel.

Protection against pertussis by acellular pertussis vaccines (Takeda, Japan): household contact studies in Kawasaki City, Japan

To evaluate the vaccine efficacy of an acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was performed by a questionnaire survey of secondary pertussis attacks through family contact in 146 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, acellular vaccine made by Takeda Pharmaceutical Company, which contains a high level of FHA (filamentous hemagglutinin), a low level of PT (pertussis toxin) and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand, 27 siblings immunized with Takeda's acellular vaccine were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.7%). The present study revealed an efficacy rate of 93.7% for Takeda's acellular pertussis vaccine.

[Protection against pertussis by Japanese T type acellular pertussis vaccine: household contact study in Kawasaki City]

To evaluate the vaccine efficacy of acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was made by a questionnaire from secondary pertussis attack through family contact in 149 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, Takeda's acellular vaccine which contains a high level of FHA, low level of PT and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand of the siblings immunized with Takeda's acellular vaccine 27 were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.4%). The present study revealed an efficacy rate of 94.2% for the Takeda's acellular pertussis vaccine.

The optimum level of radiopacity in posterior composite resins

Radiopacity is an indispensable property of composite resins for clinical diagnosis. The level of radiopacity that is most compatible with the radiographic diagnosis of recurrent caries was studied in a two-part experiment. In the first part, 16 composities were evaluated and divided into four groups based on their levels of radiopacity compared with an aluminum stepwedge. In the second part, caries was simulated by grooves of increasing depth in aluminum blocks of a thickness equivalent in radiopacity to enamel and the detectability assessed beneath differing thicknesses of three representative composite resins, P-30, Brilliant Lux and Occlusin. The relative radiographic density was measured and P-30 found to have the greater contrast. It is proposed that composite materials with a radiopacity similar to enamel are best for the detection of recurrent caries.

Diverse effects of ADP-ribosyl transferase inhibitors on G2 progression and lethality in Chinese hamster ovary cells damaged by DNA-interfering agents

DNA-damaging agents used in this study could be divided into two groups, according to their ability to retard G2 traverse. One group included monofunctional alkylating agents, such as N-methyl-N-nitrosourea, dimethyl sulfate, and Streptozotocin. Cells treated with them, which at the tested doses only slightly affected cell cycle progression from the G2 phase to mitosis, were retarded in going through mitosis by subsequent treatment with adenosine diphosphate-ribosyl transferase (ADPRT) inhibitors, such as benzamide, 3-aminobenzamide, nicotinamide, and theophylline, but not by caffeine. Effects of caffeine on G2 progression could be distinguished from those of the other ADPRT inhibitors, and even from the effects of another methylxanthine, theophylline. In addition, the lethality of the monofunctional alkylating agents was markedly enhanced by all of the ADPRT inhibitors, including caffeine. The other group consisted of a variety of agents, including intercalators (Adriamycin and Actinomycin D), a radiomimetic agent, Bleomycin, and a bifunctional alkylating antibiotic, Mitomycin C. They prevented cells from going through mitosis to different degrees. The G2-prolonged cells were variously responsive to ability of the ADPRT inhibitors to release G2-arrest and to enhance cell death.