Secreted and tumour targeted human carboxylesterase for activation of irinotecan

Irinotecan (CPT-11) is an anticancer agent for the treatment of colon cancer. CPT-11 can be considered as a prodrug, since it needs to be activated into the toxic drug SN-38 by the enzyme carboxylesterase. An approach to achieve tumour specific activation of CPT-11 is to transduce the cDNA encoding carboxylesterase into tumour cells. A secreted form of carboxylesterase may diffuse through a tumour mass and may activate CPT-11 extracellularly. This could enhance the antitumour efficacy by exerting a bystander effect on untransduced cells. In addition a secreted tumour-targeted form of carboxylesterase should prevent leakage of the enzyme from the site of the tumour into the circulation. We have constructed a secreted form of human liver carboxylesterase-2 by deletion of the cellular retention signal and by cloning the cDNA downstream of an Ig kappa leader sequence. The protein was secreted by transfected cells and showed both enzyme activity and efficient CPT-11 activation. To obtain a secreted, tumour-targeted form of carboxylesterase-2 the cDNA encoding the human scFv antibody C28 directed against the epithelial cell adhesion molecule EpCAM, was inserted between the leader sequence and carboxylesterase-2. This fusion protein showed CPT-11 activation and specific binding to EpCAM expressing cells. Importantly, in combination with CPT-11 both recombinant carboxylesterase proteins exerted strong antiproliferative effects on human colon cancer cells. They are, therefore, promising new tools for gene directed enzyme prodrug therapy approaches for the treatment of colon carcinoma with CPT-11.

Casein digestion by Debaryomyces hansenii isolated from cheese

To understand the possible proteolytic contribution of yeast during cheese ripening, Debaryomyces hansenii 212 was isolated from commercial blue-veined cheese and incubated in a medium containing casein. Growth and casein degradation were recognized at the cheese-ripening temperature. Proteolytic activity was found in the intracellular fraction, and the enzyme, which was attached to the cell wall, primarily acted on beta-casein. The cytosol contained more than 90% of the total proteolytic activity which was responsible for the degradation of both alpha(s)- and beta-casein. These results suggest that the contribution of yeast to cheese ripening would depend on the susceptibility to cell lysis in addition to its proteolytic activity.

Impact of respiratory syncytial virus infection as a cause of lower respiratory tract infection in children younger than 3 years of age in Japan

BACKGROUND

Respiratory syncytial virus (RSV) is the most important viral pathogen for lower respiratory tract infection (LRI) in infants and children. An RSV-specific monoclonal antibody has been developed to provide prophylaxis against RSV associated LRI (RSV-LRI). The objective of this study was to determine the impact of RSV as a cause of LRI in children younger than 3 years of age to provide data to aide in the implementation of forthcoming prophylaxis against RSV.

METHODS

We analyzed the viral etiology of LRI in hospitalized Japanese children younger than 3 years of age admitted to Shizuoka Red Cross Hospital from July, 1997 to June, 2000.

RESULTS

A total of 535 patients younger than 3 years of age were hospitalized with LRI at Shizuoka Red Cross Hospital from July 1, 1997 to June 30, 2000. Of these, a positive diagnosis of RSV infection was made in 168 patients (31.4%). Most of the patients with RSV infection had been well and had had no underlying disease that was defined as risk factor of RSV infection (94.0%). The peak incidence of LRI was observed in the winter each year and the number of LRI was strongly associated with the epidemic of RSV (r=0.700, P<0.0001). The number of patients with LRI younger than 6 months of age was 116 (21.7%). Of these 116 patients younger than 6 months with LRI, 55 patients (47.4%) were confirmed to have RSV infection. The proportions of RSV infection to total LRI was greatest in early infants younger than 6 months (P<0.0001). The number of patients with which RSV infection was detected in LRI patients younger than 3 years was highest during the first five months of life and there was a dramatic decrease in incidence of RSV infection with increasing age thereafter.

CONCLUSIONS

The incidence of LRI hospitalization is highly affected by RSV infection epidemic. The proportion of RSV infections among early infants younger than 6 months is greater than that of older patients. The prophylaxis against RSV will be needed to be toward early infants.

Identification of a putative vacuolar serine protease gene in the rice blast fungus, Magnaporthe grisea

We identified and cloned a gene designated SPM1, encoding a serine protease from the rice blast fungus Magnaporthe grisea. SPM1 is a single-copy gene, encoding a subtilisin-like serine protease with 536 amino acids. Analyses of the deduced amino acid sequence of SPM1 suggested that SPM1 would be localized in a vacuole, an important organelle in pathogenicity.

Additional locus of rDNA sequence specific to the X chromosome of the liverwort, Marchantia polymorpha

The molecular cytogenetic organization of 17S ribosomal RNA genes (17S rDNA), a part of the 45S rDNA repeat, was investigated on the chromosomes of the liverwort Marchantia polymorpha using fluorescence in-situ hybridization (FISH). The numbers of 17S rDNA loci visualized in female and male chromosomes were ten and nine. respectively. This heterogeneous localization was due to the presence of an additional 17S rDNA locus on the X chromosome and its absence on the Y chromosome. The signal on the X chromosome covered almost the entire region of its long arm. The other nine signals were observed on the same loci of respective autosomes in both sexes. Southern hybridization analysis revealed an additional band including 17S rDNA exclusively on EcoRI digested female genomic DNA supporting the existence of an additional 17S rDNA locus on the X chromosome.

[Diagnosis with bone mass]

In diagnostic criteria of osteoporosis proposed by WHO, the severe osteoporosis is defined as a patient with a value for BMD or BMC more than 2.5SD below the young adult mean value in the presence of one or more fragility fractures. When severe fragility fracture occurs from the second to forth lumbar vertebra, the lumbar BMD could be over-estimated. On the other hand, when the lumbar BMD is markedly low, the demarcation of bone contour is incomplete, and the precision of the BMD measurement decreases. Thus, in the severe osteoporosis it is necessary to be careful in the diagnosis with bone mass using DXA.

Relation between smoking prevalence and various social factors in Japan

Although the smoking prevalence among women is significantly low compared to that among men in Japan, the prevalence in young Japanese women has been steadily increasing recently. The relationship between the prevalence of smoking among the general population and various social factors was investigated with a special emphasis regarding the influence of household size on the smoking prevalence of young Japanese women. Thirty-one thousand and six hundreds twenty-seven subjects of 20 years and older were randomly selected from the general population of Japan. The Ministry of Health and Welfare, Japan planned and conducted the survey. Subjects were divided into male and female, and smoking prevalence was investigated in terms of age, place of residence, occupation and household size factors. Statistical analyses were performed using chi-square test and multiple logistic regression. Multiple logistic regression analyses suggested that for men there was a strong relationship between becoming a smoker and living in a municipality with a smaller population, and that for women who were living in a municipality with a larger population. For women, as the size of a household increased from living alone to a two- or three-generation household, the tendency to becoming a smoker decreased, but this tendency was not observed among men. As to reasons for quitting smoking, more women than men living in two- and three-generation households gave "family's advice" as a major reason (p < 0.01). The steady replacement of the traditional three-generation household by smaller households in Japan may lead to an increase in the number of young women who smoke.

Risk factors for severe respiratory syncytial virus-associated lower respiratory tract infection in children

BACKGROUND

Respiratory syncytial virus (RSV) is the most important cause of viral lower respiratory tract infection that can be a life-threatening disease in infants and children. This study was conducted to look for independent risk factors for severe respiratory syncytial virus-associated lower respiratory tract infection (RSV-LRI) that required oxygen supplementation or mechanical ventilation.

METHODS

Medical records of patients younger than 4 years hospitalized with RSV-LRI at Shizuoka Red Cross Hospital from July 1, 1995 to June 30, 1999 were reviewed. The patients were compared using univariate and multivariate logistic regression analysis.

RESULTS

A total of 157 patients were hospitalized with RSV-LRI at Shizuoka Red Cross Hospital from the study time period. Of these, 20 patients (12.7%) were diagnosed with severe RSV-LRI. Subjects younger than 3 months of age had an odds ratio (OR) of 59.9 (95% confidence interval (CI) 14.7_244.0) for the dependent variable of severe RSV-LRI (P<0.0001). Subjects with a history of congenital heart disease also had an OR of 99.2 (95% C1 8.5-1160.1) (P<0.0005).

CONCLUSIONS

Infants younger than 3 months without any underlying diseases may be at high risk for severe RSV-LRI. Respiratory syncytial virus prophylaxis is needed not only for high-risk patients, but for healthy early infants.

[Blood concentrations and secretory capacity of calcitonin in blood in osteoporosis]

The deficiency of calcitonin, CT, which has an inhibitory effect of bone resorption might be related to the pathogenesis of osteoporosis. Therefore, in this paper, in regard to the sex difference, the changes with aging, and the comparison with patients with osteoporosis and normal controls, the basal value and the secretion capacity of CT concentrations in the blood, and the metabolic clearance rate, MCR, and the production rate, PR, of CT have been reviewed.

[Implementation and evaluation of public relations activity in a community health program]

OBJECTIVE

This study evaluated public relations activity in a community health program in order to develop effective strategies to attract the public attention for the program.

METHODS

An intervention study was conducted on public relations for "Nutrition Seminar for Citizens," sponsored by the Health Department of Machida City, Tokyo, in October, 1999. One ward in the city was selected as an intervention area, and another ward which had similar demographic and geographic characteristics was chosen as a control area. Two target populations were defined; one was women in their 20s to 60s (#1) and the other was those who had previously never utilized community health programs sponsored by the city (#2). Handbills were used as the medium for public relations for the seminar. These announced the time, place and content of the nutrition seminar and were designed by authors with special attention to catchphrases, colors and fonts. Handbills were distributed in the intervention area through elementary schools, local voluntary organizations and local health volunteers. In addition, the authors directly handed them out to people in front of two supermarkets in the town. The sources of seminar information were requested from the participants of the Nutrition Seminar with a self-administered questionnaire.

RESULTS

1. The percentage of participants who received the seminar information from handbills was higher than that of those who used monthly newsletters from the city as a source of information. 2. The percentage of participants from the intervention area was higher than that from the control area. 3. Regarding target populations #1 and #2, there were no differences in participation rates between the intervention and control area. 4. Among the four distribution routes, the local voluntary organization route was the most effective for attracting participants.

CONCLUSIONS

The results show that handbills can be an effective medium for pubic relations to increase the number of participants in community health programs. Also, local voluntary organizations can play a crucial role in information transfer in the community because of their high credibility. On the other hand, we could not reach specified target populations with the medium. Further surveys are needed to establish optimal media and routes to reach appropriate target populations in health programs.

The Y chromosome in the liverwort Marchantia polymorpha has accumulated unique repeat sequences harboring a male-specific gene

The haploid liverwort Marchantia polymorpha has heteromorphic sex chromosomes, an X chromosome in the female and a Y chromosome in the male. We here report on the repetitive structure of the liverwort Y chromosome through the analysis of male-specific P1-derived artificial chromosome (PAC) clones, pMM4G7 and pMM23-130F12. Several chromosome-specific sequence elements of approximately 70 to 400 nt are combined into larger arrangements, which in turn are assembled into extensive Y chromosome-specific stretches. These repeat sequences contribute 2-3 Mb to the Y chromosome based on the observations of three different approaches: fluorescence in situ hybridization, dot blot hybridization, and the frequency of clones containing the repeat sequences in the genomic library. A novel Y chromosome-specific gene family was found embedded among these repeat sequences. This gene family encodes a putative protein with a RING finger motif and is expressed specifically in male sexual organs. To our knowledge, there have been no other reports for an active Y chromosome-specific gene in plants. The chromosome-specific repeat sequences possibly contribute to determining the identity of the Y chromosome in M. polymorpha as well as to maintaining genes required for male functions, as in mammals such as human.

[Bone metabolic markers and diagnosis of abnormal bone and calcium metabolism]

Bone metabolic markers increase in blood or urine, when bone formation or bone resorption accelerates. Reference values of bone metabolic markers are determined in male or female, and in pre- or post-menopause, respectively. Values of bone metabolic markers in most patients with primary osteoporosis were distributed within a reference value, mean+/-1.96 SD. When measured values exceeded a reference values, we should survey a possibility of abnormal calcium or bone metabolism such as primary hyperparathyroidism, renal osteodystrophy, hyperthyroidism and Paget's disease of bone or bone metastasis associated with malignant tumor.

Establishment of a new cross of the rice blast fungus derived from Japanese differential strain Ina168 and hermaphroditic rice pathogen Guy11

Mating experiments between Magnaporthe grisea Japanese rice pathogens and Guy11, a hermaphroditic fertile rice pathogen, were done aimed at identification of avirulence genes. A cross named cross 2107 with thirty-six random progenies was obtained. Segregation analyses of genetic markers found that the cross was less suitable for genetic analysis. Backcrosses with cross 2107 progenies and Guy11 were done and another cross named cross 5307 with sixty-five progenies was obtained. A locus controlling kasugamycin resistance named Ksg1R was identified and used for a model case of genetic mapping. Bulked segregant analysis was done to find adjacent RAPD markers for mapping of the gene. Three adjacent markers to Ksg1R were obtained and a genetic map around the Ksg1R was made, but these markers were not located on a single chromosome. These results suggest that genetic analysis to identify a gene locus is available in cross 5307. Infection assay of parental strains of cross 5307 to Japanese differential rice cultivars suggested the possibility of genetic analysis of cultivar specificity toward four rice cultivars: Aichi-asahi, Kusabue, Tsuyuake, and K59.

The influence of lifestyle and health status factors on sleep loss among the Japanese general population

STUDY OBJECTIVE

To examine the relationship between lifestyle, health status factors and sleep loss.

DESIGN

A cross-sectional questionnaire survey conducted by the Ministry of Health and Welfare, Japan.

SETTING

N/A.

PATIENTS OR PARTICIPANTS

Approximately 30,000 subjects selected from the general population in Japan.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

This study indicated that approximately 28% of the general population sleep less than 6 hours nightly and approximately 65% sleep less than 7 hours. However, approximately 80% of the population reported getting sufficient sleep. Multiple logistic regression analysis showed that being females, being of younger age, living in an urban environment, being unemployed, and having an unhealthy lifestyle (i.e., lack of exercise, poor health status, and irregular eating habits) were associated with sleep loss.

CONCLUSION

In this study, sleep loss was found to be associated with having an unhealthy lifestyle and being in poor general health. These findings suggest that health education and promotion of a healthy lifestyle should be advocated.

Relation of a common methylenetetrahydrofolate reductase mutation and plasma homocysteine with intimal hyperplasia after coronary stenting

BACKGROUND

Hyperhomocysteinemia has been identified as an independent risk factor for coronary artery disease. Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to mild hyperhomocysteinemia and, therefore, to the incidence of coronary artery disease. No information exists, however, regarding the association between the mutation of the MTHFR gene or plasma homocysteine levels and morphological analysis of coronary atherosclerosis using intravascular ultrasound.

METHODS AND RESULTS

To examine the potential influence of MTHFR genotype and homocysteine on coronaryarteries morphologically, we screened 62 patients with 65 lesions that were treated with 93 Palmaz-Schatz stents. The plasma homocysteine levels in the patients with the TT genotype were not significantly higher than those in the patients with non-TT (CC+CT) genotypes (13.1 +/- 5.5 versus 11.5 +/- 3.1 mmol/L, P=0.16). Angiographic analysis showed that the percent diameter stenosis in the patients with the TT genotype was significantly greater than that in those with non-TT genotypes (43.7 +/- 17.8% versus 29.0 +/- 22.0%, P=0.015). Intravascular ultrasound analysis showed that the TT genotype was significantly associated with greater intimal hyperplasia area (5.70 +/- 1.94 versus 3.72 +/- 1.38 mm2, P=0.001). In multiple stepwise regression analysis, the number of the T alleles was the only independent predictor of intimal hyperplasia after intervention (r2=0.21, P=0.004).

CONCLUSIONS

The homozygous mutant genotype of the MTHFR gene may increase the risk of in-stent restenosis more than does the normal homozygous or heterozygous genotype.

Smoking behavior and related factors among Japanese nursing students: a cohort study

BACKGROUND

Although there have been several surveys on smoking behavior among Japanese nursing students, most have been cross-sectional studies. No longitudinal studies, such as a prospective cohort study, have ever been carried out. We therefore conducted a cohort study on, and analyzed smoking behavior and related factors among, Japanese nursing students.

METHODS

A survey on smoking behavior using a confidential questionnaire was conducted on nursing students at two vocational schools of nursing and two nursing colleges/universities located in the Tokyo metropolitan area. Another survey was subsequently conducted in the same manner among the same subjects 1 year later. The surveys were conducted between 1997 and 1999.

RESULTS

Over the 1-year period, the prevalence of smoking among nursing students increased by 10% for students at the vocational schools of nursing (n = 224) and by 3% for students at the nursing colleges/universities (n = 222). The average score for nicotine dependence for students who were daily smokers at both time points rose from 3.6 to 4.4 (P < 0.05). Two factors found to significantly predict smoking behavior were having friends who smoke and living alone.

CONCLUSION

Smoking prevalence is increasing among Japanese nursing students. Smoking prevention and cessation interventions should be instituted in all nursing training programs.

Structure and function analysis of the calcium-related gene spray in Neurospora crassa

The spray gene was cloned, and wildtype and mutant alleles were sequenced. Spray(+) has a 3452-bp open reading frame plus seven introns. The spray mutant had a T --> G transversion close to the carboxyl end, creating a stop codon (TGA). The sequence shows no match to genes of known function, but the carboxyl end shows seven transmembrane domains and matches putative membrane proteins of yeast. The most abundant transcript detected was 4.4 kb in size. Repeat-induced point mutagenesis produced the mutant spray phenotype. Electrophysiological analysis showed that ion fluxes in the spray plasma membrane are normal; furthermore, whereas the spray mutant was known to have no organelle-based calcium fluorescence, the cytosol shows a tip-high calcium gradient. The spray mutant is sensitive to calcineurin inhibitors. The results suggest that the SPRAY protein is located in an organellar membrane, regulating the distribution of Ca(2+) via calcineurin.

[Usefulness of combination therapy of hybrid thrombolysis followed by back-up percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction]

OBJECTIVES

Conventional thrombolytic therapy for acute myocardial infarction is effective for early reperfusion but has the disadvantage of a higher rate of bleeding complications. The purpose of this study is to elucidate efficacy and safety of a combined approach using a bolus injection of low dose of mutant tissue plasminogen activator (mt-PA) with heparin and aspirin to ensure definite antithrombin and antiplatelet efficacy, followed by back-up percutaneous transluminal coronary angioplasty(PTCA).

METHODS

Patients with acute myocardial infarction aged < 80 years who were admitted to our institution within 3 hr of onset of symptoms were immediately treated with oral aspirin 330 mg and intravenous heparin 5,000 IU and were randomized to receive an intravenous bolus of mt-PA (monteplase) 15,000 IU/kg (thrombolytic group, n = 25) or no mt-PA (control group, n = 21), followed by angiography with PTCA if indicated.

RESULTS

There were no differences between the two groups in patient characteristics, time from onset to hospital arrival, time to initial angiography, or infarct-related arteries. Significantly more patients had Thrombolysis in Myocardial Infarction flow grade 3 and grade 2/3 at the initial angiography in the thrombolytic group than in the control group (32.0% vs 4.8%, 68.0% vs 14.3%; p = 0.020, p = 0.0003, respectively). PTCA was performed in 88% of the thrombolytic group (stenting employed in 64%) and 95.5% of the control group (stenting in 57%), and the success rate was 95.5% and 100%, respectively. No acute or subacute coronary occlusion was found in either group. Bleeding complications occurred in only one patient in the thrombolytic group, which was bleeding associated with vomiting, and no difference was found in other complications between the two groups. Radionuclide ventriculography using quantitative gated single photon emission computed tomography showed left ventricular end-diastolic volume and left ventricular end-systolic volume tended to be smaller, and the ejection fraction after 3 months of treatment tended to be higher in the thrombolytic group. Myocardial salvage volume was significantly higher in the thrombolytic group.

CONCLUSIONS

Hybrid thrombolysis using a low dose of mt-PA with aspirin and heparin promoted significantly early reperfusion. Also, successful reperfusion is achievable at higher rates with back-up PTCA without an increase in complications.

Apparent change of masking functions with compression-type digital hearing aid

Signal perception ability under conditions of a narrow band masker in subjects with hearing aids was examined using a theoretical model of the auditory nerve fibre (ANF) with a deteriorated tuning curve in addition to measurements of actual masking function in subjects wearing hearing aids. The results obtained indicate that the apparent masking function could be affected by the frequency-gain character as well as by the degree of compression. Usually, the compression-type of amplification with flat and/or high-frequency weighted characteristics improves not only the apparent thresholds but also the apparent masked thresholds under conditions of lower frequency masking. On the other hand, a low-frequency masker amplified by a higher gain with low-frequency weighted amplification could cause larger upward-masking effects on the signal perception of the higher frequency signal in some conditions. The present study may contribute to our understanding of the underlying mechanisms of the effects of different amplification by the aid.

Effect of quinapril on intimal hyperplasia after coronary stenting as assessed by intravascular ultrasound

We studied whether angiotensin-converting enzyme inhibition with quinapril treatment can prevent in-stent restenosis after successful implantation of Palmaz-Schatz stents. Intravascular ultrasound study, but not quantitative coronary angiography analysis, revealed that quinapril treatment significantly prevented the loss of both minimal lumen cross-sectional area and lumen volume in stents, in addition to reducing the increase in intimal hyperplasia volume.

[Study of factors that influence the use of ambulances in Japanese prefectures]

PURPOSE

The objective of this study was to clarify the factors that influence the rate of patient-carriage by ambulances in Japanese Prefectures.

METHOD

The study was conducted using data on cases of patients with mild conditions carried by ambulances in Japanese prefectures in 1993, concentrating the factors that influence the rate of usage. The cases were analyzed focusing on three major types of medical emergencies (accounting for 93.4% of the total): sudden illnesses, traffic accidents and general injuries. SPSS for Windows was used for statistical analysis.

RESULTS AND DISCUSSION

Data analysis by age group and type of medical emergency showed a positive correlation (r > 0.7) for the rate of cases with mild conditions carried by ambulances in all age groups (early childhood, adolescence, adult and senior) and the three major types of medical emergencies. Particularly, a strong correlation (r > 0.9) was observed with regard to patients suffering from sudden illnesses and general injuries. Multiple regression analysis showed that the rate for patients with mild cases carried by ambulances was higher in prefectures where; (1) there were more cases of administrative litigation related to individuals' rights, and (2) there were many nuclear families that tended to lack the capacity for family care. In addition, it also became evident that the rate for patients with mild injuries from traffic accidents was higher in prefectures where; (1) the rate for male-driver license holders for small- and medium-size cars was higher, and (2) the ratio of numbers of vehicles to total roadway area was higher.

CONCLUSIONS

The findings suggest that factors unrelated to medical emergencies have a major influence on use of ambulance. Reevaluation of policy in order to promote appropriate utilization is necessary.

[Diagnostic imaging of osteoporosis: special reference to diagnosis by radiography and DXA]

Primary osteoporosis is diagnosed by diagnostic criteria, eg. whether non-traumatic vertebral body is or not, or the severity of low bone mass. As a diagnostic imaging of osteoporosis, grading of radiographic osteopenia, and Singh index in the upper end of femur are well-known. Vertebral fracture associated with osteoporosis shows wedge, fish or flat deformity, but it is necessary to differentiate from Schmorl node and so on. DXA is a main stream of bone mineral quantification method, and its image is expressed the distribution of bone mineral density per unit area.