Control of expression by the cellulose synthase (bcsA) promoter region from Acetobacter xylinum BPR 2001.

The 5' upstream region (about 3.1kb) of the cellulose synthase operon (bcs operon) has been isolated by cloning from Acetobacter xylinum strain BPR 2001. The expression level of the upstream region was determined using sucrose synthase cDNA as a reporter gene in the shuttle vector pSA19. The expression occurred with the 1.1-kb upstream sequence from the ATG start codon of the bcs operon but not with the 241-bp upstream sequence in A. xylinum, although neither the 1.1-kb nor the 241-bp upstream sequence caused any expression as a promoter in Escherichia coli. The level of expression with the 1. 1-kb upstream sequence in A. aceti was 75% of that in A. xylinum. These results suggest that the upstream region functions as a specific promoter for the Acetobacter genus. The expression was reduced by the introduction of the 241-bp upstream region between the lac promoter and the reporter gene in E. coli and was not detected in A. xylinum. This suggests that the short upstream region composed of 241bp contains the site(s) which causes a negative regulation on the transcription for bcs operon. The production of recombinant protein with the ribosome-binding site (RBS) of A. xylinum obtained from the bcs operon, was reduced to about half in E. coli, and that with the site of the lac promoter was also reduced to about half in A. xylinum. This shows that a species-specific predominance occurs during interaction between mRNA and 16S rRNA in the RBS between A. xylinum and E. coli.

Geranylgeranylacetone and cetraxate hydrochloride increase UDP-galactosyltransferase activity in rat gastric mucosa.

UDP-galactosyltransferase (UDP-Gal-T) is a key enzyme in the synthesis of mucus glycoprotein which plays an important role in gastric mucosal defensive mechanisms. Analysis of gastric UDP-Gal-T activity should clarify the mechanisms of the action of antiulcer drugs regarding gastric defensive factors. Here, we examined UDP-Gal-T activity in rat gastric mucosa treated with the antiulcer drugs geranylgeranylacetone (GGA) and cetraxate hydrochloride (CET). The effects of coadministration of indomethacin and exogenous administration of prostaglandins (PGs) were also studied. GGA and CET significantly increased UDP-Gal-T activity, and coadministration of indomethacin inhibited the increase of enzyme activity. UDP-Gal-T activity level with GGA was significantly higher than the control level, even in the presence of indomethacin. With CET, however, this was not the case. Among PGs, PGE1 significantly increased enzyme activity. Concomitant administration of PGE1 and GGA or CET increased UDP-Gal-T activity even with indomethacin to the levels achieved when these antiulcer drugs were administered without indomethacin. Our findings suggest that GGA and CET exert antiulcer effects by increasing mucus glycoprotein synthesis and that endogenous PG synthesis may be involved in this process. However, mechanisms not mediated by endogenous PGs may also exist in the stimulatory action of GGA on UDP-Gal-T activity.

Effect of a pelvic belt on abdominal pressure by various weights and bending angles.

Back support belts are one of the important measures for preventing low back pain. One theory attributes the effectiveness of such a belt to the intraabdominal pressure it applies. The purpose of this study was to investigate the effect of a pelvic belt on abdominal pressure when the subject held four different weights at four different bending angles. The subjects of the study were ten male students who did not suffer low back pain. They wore a cuff with a blood pressure meter on their abdomens under the pelvic belt. They held a weight for 5 s slightly above an adjustable stand at a specified forward bending angle. The external abdominal pressure (EAP) was measured 4 s after lifting the weight. The weight was 0, 10, 20 or 30 kg; the angle was 0, 30, 60 or 90 degrees; there were 4 x 4 = 16 trials/subject. As the weight increased (at all angles), EAP increased significantly. However, at 0 kg and 10 kg, EAP decreased as the angle increased; at 0 kg, EAP decreased significantly. Thus, the belt should be effective for manual material handling due to the sensitive response of EAP for low back load. With light weights such as 0 kg and 10 kg, it is better to use the belt at small bending angles than at large bending angles because EAP decreases as the angle increases.

Swell-preventing effect of intermittent exercise on lower leg during standing work.

This study investigated the effectiveness of several possible exercises for performance during standing work in order to prevent lower leg swelling and relieve subjective complaints. Volume changes in the lower leg were measured using bioelectrical impedance plethysmography in 13 healthy male subjects aged 23-36 years. Subjective complaints of leg pain, leg dullness and whole body fatigue were also recorded. Measurements were performed at two-minute intervals during a one-hour period of standing with insertions of one-minute of exercise every 10 min. The exercises were knee-bending, foot-stepping, walking, and heel-raising. The change rates of impedance over one hour were 2.2%, 4.0%, 4.6%, and 6.3%, respectively, indicating that leg volume was increased under all exercise conditions. Among exercises, the swell-preventing effect of knee-bending was strongest, and that of heel-raising was weakest. Heel-raising also yielded the highest number of subjective complaints. Knee-bending, which uses the thigh and calf muscles simultaneously, was considered the most effective for suppressing lower-leg swelling and minimizing subjective complaints.

The effect of a tilting seat on back, lower back and legs during sitting work.

The purpose of this study was to examine the possible effects of a tilting seat on the back, lower back and legs. Ten healthy male subjects aged 22-28 performed word-processing operations while sitting on a chair for one hour under two different seating conditions: the rocking condition and the fixed condition. While the subjects were performing the task, measurements of lower leg swelling were taken using bioelectrical impedance plethysmography, and pain scores were recorded every five min for the neck, shoulders, back, lower back, hips and legs. Electromyograms (EMGs) of the back and lower back (at Th5-6, Th8-9, L1-2 and L3-4) were recorded every sec. In addition, the subjects were videotaped while using the rocking seat, in order to analyze the angle and frequency of seat tilting. At the end of the experiment, the subjects were asked to evaluate the two conditions with respect to localized fatigue and operational efficiency. There was no significant difference in lower leg swelling between the two conditions. EMGs were significantly different at Th5-6, Th8-9 and L1-2 between the two conditions. The rocking condition generated greater EMGs at Th5-6 and L1-2, whereas the fixed condition produced greater EMGs at Th8-9. The pain scores for the neck, shoulders, back and lower back were higher under the fixed condition, while those for the buttocks were higher under the rocking condition. The average tilting frequency was as low as 25.2 times per hour, with 15.6 times per hour for tilting angles ranging from 1 to 2 degrees, and 9.6 times per hour for tilting angles exceeding 2 degrees. As for the subjective evaluations of localized fatigue, seven of the ten subjects preferred the rocking condition, while two preferred the fixed condition and one subject had no preference. Thus, there was a significant difference in the subjective evaluations of the two chairs. These findings suggest that the rocking condition, in contrast to the fixed seating condition, reduced back and lower back pain as a result of its tilting capability. The results of EMGs suggest that the rocking condition reduced back and lower back pain by increasing the overall muscle activity of the back and lower back. The leg impedance measurements showed no effect of the rocking condition on the leg swelling, as compared with the fixed condition.

An electromyographic study of two different types of ballpoint pens--investigation of a one hour writing operation.

Recently there has been an increasing incidence of occupational cervicobrachial disorders (OCD) and writer's cramp in office workers using ballpoint pens in writing operations. For the sake of workers who use ballpoint pens, it is essential to prevent such health hazards. It has been observed that a strong gripping pressure on the ballpoint pen significantly contributes to the development of these conditions. The present authors have been developing a new ballpoint pen by altering the grip area in such a way as to reduce the gripping pressure, and thus prevent OCD. The purpose of this study is to compare our ballpoint pen (new pen) with a conventional ballpoint pen (conventional pen) for the load that they exert on the upper limb during one hour of continuous writing. Electromyograms (EMG) and upper limb pain scores are used as indicators. The conventional pen used was selected from commercially available ballpoint pens widely used in offices. The grip area is cylindrical with an 8.3 mm diameter. It is manufactured of hard plastic, which can make it feel rigid and slippery to the user. The new pen has a cylindrical grip area that flares out at the bottom, near the pen-tip, and has a diameter ranging from 11.9-13.6 mm. In addition, the grip is constructed of a 2 to 3 mm-thick silicon rubber sleeve that is softer and less slippery in comparison with the conventional pen. Twelve students (5 males and 7 females) without any preexisting cervicobrachial disorders were asked to transcribe an English text for one hour, alternately using the two kinds of pens. The EMG of the flexor pollicis brevis was measured and recorded every second, while subjective pain scores were recorded every five minutes for the thumb, forefinger, middle finger, thenar, forearm extensor (forearm) and shoulder. The EMG of the flexor pollicis brevis and the pain scores for the thumb, forefinger, middle finger, forearm and shoulder were significantly lower for the new pen than for the conventional pen. These results suggest that after an hour of continuous writing, the new pen reduces the muscle load on the upper limb, and therefore mitigates fatigue in this area.

Development of a system for analyzing working postures.

In order to assist in the analysis of working postures which might cause lumbago in the field of industrial health, a system was developed for the synchronous recording and analyzing of postures, work content and physiological data. The system is composed of a portable unit for recording 3 channels of goniometers, 1 channel of inclinometer and 1 channel of surface electromyogram, a video camera for recording work content, a host computer and some peripheral devices for analyzing the data from the portable unit and video camera. In this system, postures are automatically classified from data on joint angles and upper body inclination angle by using a discriminant function. The joint angles are measured by the goniometers using rubber optical fibers. The angle of upper body inclination is obtained by the inclinometer using a magnetic resistance sensor. In addition to the work content and video images, the postures and the electromyogram can be analyzed and confirmed by simultaneous display of the data on the host computer screen. Based on the trial use of this system in a work model of manual baggage handling, it was proved useful for evaluating in detail the workload caused by working postures.

Statistical analysis and prediction on incidence of infectious diseases based on trend and seasonality.

We proposed a prediction methodology for the incidence of infectious diseases using incidence data on measles and influenza for forty years in Japan. We also proposed a diagram that makes it possible to convey information on infectious disease incidence more attractively to a wider audience. This can be a useful tool for health promotion in the community. The obtained results are as follows: 1. It was advantageous to use data transformed by logarithm in statistical analysis of infectious disease incidence. 2. The incidences of measles and influenza exhibited strong seasonality. Measles was most frequent in June and influenza in February. 3. Long-term trends were extracted from the derived data obtained by eliminating seasonal effects from the original data. For measles, a decline was accelerated by the introduction of vaccination program in 1978. Influenza also showed a decline for these thirty years. 4. The observed incidence data were quite well predicted by only the trend and the seasonality. The squares of multiple regression coefficients of measles and influenza were 0.84 and 0.58, respectively. The analysis of the residuals suggested there was a possibility of improvement in prediction. 5. The improvement in prediction was attained by incorporating an autoregressive component of the residuals. As a result, the squares of multiple correlation coefficients of measles and influenza increased to 0.97 and to 0.79, respectively. 6. We finally proposed the TS-decomposition diagram to facilitate practical use of incidence data. In this diagram, current incidence data and predicted values for the near future are plotted on the plane where the trend and the seasonality are superimposed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Analysis of participation rates of atomic bomb survivors in health examinations].

Participation rates of atomic bomb survivors in health examinations were analyzed with a multiple logistic regression model. Rates were obtained for each stratum by sex, age group and residential ward. The effect of residential wards was considered in relation to the social indices of the wards. The effects of sex, age group and residential ward on participation rates were as follows: (1) Females had higher participation rates than males in the working age group (40-64). No sex differences were seen after age 65. (2) The participation rates had a peak around age 70 and were exceptionally high also in the youngest age group (40-44). (3) Participation rates were higher in suburban wards than in central wards. The participation rates had a negative correlation with urban characteristics while they had a positive correlation with suburban characteristics. In particular they had significant negative correlation to the number of clinics and positive correlation with voter participation rates in elections. These results suggest the need for a new type of urban health examination and reflection of the general attitude of the residents to the government.

[Current and future perspectives of medical information network systems for community health using personal computers and IC cards].

Recent developments in computer and communication technology were studied in relation to medical information network systems, using computers and IC cards, to solve problems in community health. Trial use of personal computer network systems among physicians and IC card systems for personal health data management are already in existence in some parts of Japan. These trials were studied and analyzed based on a questionnaire survey of physicians and patients. Results of the study produced some useful points that should be considered when introducing these systems. These included: 1) details on expectations and specifications for these systems by physicians and patients, 2) easy access to valuable information is a key point for active network systems among physicians, 3) plausibility of improvement of communication between physicians and patients by using these systems, 4) recognition that an important problem concerns patient information privacy and must be considered before introducing these systems. A study of practical merits of these systems and methodology for realization indicates that participation by active and attractive providers of information can be expected to stimulate frequent use of the network system. The cost of introducing these systems can be partially borne by eliminating the large investment now allocated for processing requests for reimbursement of medical services. Investigation into the introduction of medical information systems provides a good opportunity to elucidate problems in the present medical systems.

[Survey of attitudes among general practitioners regarding the introduction of a personal computer medical network system in community health care].

General practitioners (GPs) play an important part in community health care. Their opinion regarding introduction of a medical information network system using a personal computer and factors influencing the decision to introduce such a system were surveyed among 977 randomly sampled GPs. A response from 727 GPs was obtained. Based on a two stage selection method, 20 factors were selected as effective factors among the 73 factors surveyed, with the following results: (1) Responses to the question concerning the approval of system introduction were classified into three groups: "not necessary + too early to make a decision (DA)" (DA group), "approve (A)" (A group) and "undecided (UD)" (UD group). Each group had nearly equal numbers of respondees. (2) Significant effective factors were "experience with personal computers", "a desire to use a personal computer", "a desire to use a computer-diagnosis-system", "cost", and "a volition to operate a computer by himself". (3) The "A group" had high experience and affirmative opinions, while the "DA group" had low experience and negative opinions. The "UD group" also tended to respond with "do not know" regarding the factors. (4) Approval of system introduction requires providing basic knowledge on computers, opportunities for positive experience with computers, and practical examples of problem solutions in a general practitioner's work.

Bioelectrical impedance measuring method for standing load evaluation.

A bioelectrical impedance method was used to evaluate the workload in standing jobs. This method is designed to indirectly evaluate swelling of the lower leg by measuring the change in the rate of impedance of the lower leg. In this paper, we studied the relationship between the methods used for swelling evaluation, and studied the measuring conditions of the impedance method by using bioelectrical models. Furthermore, impedance in ten male subjects in three types of standing conditions was measured to check the validity of the model analysis. The results are as follows: 1) The result of theoretical analysis showed that the change in impedance caused by leg swelling is equal to the value obtained by the leg volume measuring method, and twice as great as the value obtained by the leg circumference measuring method. The rate of change in impedance at low frequency is about 4 times greater than that at high frequency. The low frequency impedance measuring method is therefore much more sensitive than the other methods. 2) The results of experimental studies showed that the impedance in the lower legs was reduced as the function of time when quietly standing for 30 mins. The change in the rate of impedance was 6.86 +/- 4.54% (mean +/- SD). This rate is 3-5 times greater than the data reported by other researchers who used volume measurement or impedance measurement at high frequency. This difference fits the results of model analysis, and proved the validity of model analysis and the usefulness of the impedance method as an index of the standing load.(ABSTRACT TRUNCATED AT 250 WORDS)

[Development of posture measuring apparatus using goniometer and inclinometer. 1. Description of the apparatus and its usefulness].

A new posture measuring apparatus was developed for time and motion study in the field of industrial health. This apparatus can record and classify working postures by measuring the angles of joints and trunk inclination. The angles of joints are measured by newly developed goniometers which use the bending loss of rubber optical fibers. The trunk inclination is measured by an inclinometer which uses photointerrupters. The measured angle data stored in the memory of this apparatus are transferred to the host computer and analyzed. Postures are classified automatically and subjectively according to discriminant functions which are calculated from the preliminarily measured data by discriminant analysis. Test measurement was carried out to classify four postures; standing, forward bending, half sitting and sitting. The goniometers were set on the right hip joint, knee joint, and ankle joint and the inclinometer was set on the right side of the trunk. The postures were changed in the order of standing, forward bending, half sitting, and sitting every 30 s. The angles were measured every second and a total of 120 sets of angles were measured. All data including data during posture changing were classified correctly by discriminant functions. The measurement during baggage lifting up and putting down was also carried out. Ten baggages (each 7 kg in weight) were lifted up from the floor onto a desk (75 cm in height), put down back to the floor, and again lifted on the desk. In 2 min, baggages were lifted up for a total of 20 times and put down for a total of 10 times.(ABSTRACT TRUNCATED AT 250 WORDS)

[Electromyogram measuring method for low back load evaluation of handling weight and forward bending posture].

In order to establish a measuring method of electromyogram (EMG) to evaluate the low back load by handling weight and forward bending angle. EMG at Th5-6, Th8-9, Th11-12, L1-2 and L3-4 were measured in ten male subjects. The handling weight was changed at 0, 10, 20 and 30 kg, and the forward bending angle was changed at 0, 30, 60 and 90 degree. The following results were obtained: 1) EMG increased according to the handling weight at all forward bending angles. The increasing rate of EMG at Th5-6 was larger than that at L1-2 or L3-4. Thus, EMG at higher position such as Th5-6 was found to be appropriate to evaluate handling weight-load. 2) The effect of forward bending angle was different by handling weight. EMG at L1-2 and L3-4 increased according to forward bending angle when the handling weight was 0 kg or 10 kg and when the forward bending angle was not greater than 60 degree. However, when the handling weight was 20 kg or 30 kg, EMG and forward bending angle did not show a simple proportional relationship. Thus, EMG at L1-2 or L3-4 could be used to evaluate posture load when the handling weight was light and the bending angle was not so large. However, it was difficult to use EMG to evaluate posture load when the forward bending angle was large or the handling weight was heavy.

Relationship between Sulfaguanidine Resistance and Increased Cellulose Production in Acetobacter xylinum BPR3001E.

The mechanism of the increased cell growth and cellulose production of Acetobacter xylinum subsp. sucrofermentans BPR3001E, a sulfaguanidine (SG)-resistant mutant, was investigated. We found that adding p-aminobenzoic acid (PABA) to cultures of the parent strain, BPR2001, led to increased levels of intracellular adenosine-related purine compounds and increased cellulose production. Furthermore, adding ATP increased the cellulose production by permeabilized BPR2001 cells. On the other hand, the intracellular levels of PABA and adenosine-related purine compounds in BPR3001E cells were higher than those in BPR2001 cells. These results suggest that SG resistance increases enhance cellulose production through increased levels of intracellular high-energy compounds caused by increased PABA biosynthesis, reflecting the promoted supply of cellulose precursors.

[Development of posture measuring apparatus using goniometer and inclinometer. 2. Fixation, precision and calibration of goniometer].

A new posture measuring apparatus was developed for time and motion study in the field of industrial health. This apparatus records working postures by measuring angles of joints and trunk inclination. The angles of joints were measured by the newly developed goniometers which use the bending loss of rubber optical fibers. This paper presents results of studies made on the fixation, precision and calibration of goniometers which are important in the actual application of this apparatus. Six freedoms of five joints were examined, i.e. elbow (flexion/extension), shoulder (abduction/adduction and horizontal adduction/abduction), hip (flexion/extension), knee (flexion/extension), ankle (dorsi-flexion/plantar-flexion). The results obtained were as follows; 1) Goniometers should be fixed according to the characteristics of each joint. 2) The output errors were calculated from the measured data, excluding the effects of flexed angles, subjects and fixations. The mean output error of all joints was 0.189 V (14.3 degree). 3) The output errors by the three calibration methods using logistic curves were calculated. The output errors for 2-point method (calibrated by the data of minimum and maximum angles) and 3-point method (calibrated by the data of minimum, medium and maximum angles) were 1.34 and 1.22 times larger than the output errors (0.139 V) for all-point method (calibrated by all measured data), respectively.

A simple apparatus using inclinometer for monitoring working postures.

A new apparatus was developed for evaluating a load on the low back caused by working postures by measuring upper body inclination. This apparatus consists of an inclinometer and a portable unit. The inclinometer that uses a magnetic resistance sensor is attached to the upper body of the subject. The portable unit, controlled by a one-chip CPU, is enclosed in a cloth case and carried by the subject on his waist belt. The inclination is measured at a certain interval and recorded in the memory of the portable unit. All the recorded data are later transferred to a host computer and then analyzed. According to the theoretical analysis by using a simple mathematical model, upper body inclination changes according to the height of work places, and one cm difference in height causes more than one degree of upper body inclination. A model work of material handling was carried out to collect sample data. Two male subjects lifted ten boxes onto a platform from a stand in several heights. Both stooped and squat lifting methods were used as the lifting protocol. The mean and standard deviation (SD) of the upper body inclination during work decreased according to the lift distance only in stooped lifting. As a practical application, working postures during the task of changing diapers for handicapped people were analyzed with out apparatus. A female subject changed diapers eight times at different height of beds. The mean value of inclination decreased according to the height of the beds.(ABSTRACT TRUNCATED AT 250 WORDS)