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Biomedical subjects

M Miki

Publications and source records attributed to M Miki.

At least 145 records · Page 8Linked to original sources

Incidence of pulmonary embolism in a chest hospital in Japan and importance of preoperative perfusion lung imaging in the diagnosis of postoperative pulmonary embolism.

The incidence of pulmonary embolism was retrospectively studied in a University Chest Institute and its affiliated hospital in Sendai, Japan, whose annual numbers of discharged patients from chest medical wards and lung operations as a whole are about 600 and 400, respectively. Before 1975 there was no documented patient with pulmonary embolism. Since then 70 patients had been clinically suspected of having pulmonary embolism and 31 of the 70 were diagnosed as having pulmonary embolism; 15 without and 16 with surgical operations in the immediate past. Fourteen of the 31 patients required combined perfusion and aerosol inhalation lung imaging for diagnosis. Twelve postoperative patients could be diagnosed as pulmonary embolism by comparing postoperative perfusion lung images taken at the time of suspicion with preoperative perfusion counterparts. Although it is said to be rising, the incidence of pulmonary embolism in a chest hospital still seems to remain low compared with that in western countries. For postoperative patients, comparison with preoperative studies was found very useful in diagnosing postoperative pulmonary embolism. The importance of preoperative perfusion lung imaging cannot be overstressed not only as a preoperative lung function test but as a baseline study to be compared with postoperative perfusion images when pulmonary embolism is clinically suspected in postoperative patients.

Female↗

The effect of alpha-tocopherol as an antioxidant on the oxidation of membrane protein thiols induced by free radicals generated in different sites.

Azo compounds enable us to generate peroxyl radicals by thermal decomposition at a constant rate and at a desired site, that is, water-soluble compounds produce initiating radicals in an aqueous phase and lipid-soluble compounds initiate the oxidation within the membrane-lipid layer. Using these radicals generated in different sites, we oxidized red blood cell ghost membranes to study the relationships between alpha-tocopherol depletion, initiation of lipid peroxidation, and protein damage. When radicals were generated in the aqueous phase, the loss of membrane protein thiols was observed concurrently with the consumption of membrane tocopherol and after tocopherol was exhausted the peroxidation of membrane lipids occurred. On the other hand, when radicals were initiated within the lipid region, the oxidation of thiols and the formation of thiobarbituric acid-reactive substances were suppressed to give an induction period until tocopherol fell below a critical level. Our results indicate that the surface thiols of extrinsic proteins may compete with alpha-tocopherol for trapping aqueous radicals and spare tocopherol to some extent, whereas the oxidation of intrinsic buried thiols may commence due to lipid-derived radicals produced after tocopherol was consumed. In conclusion, alpha-tocopherol in the membrane can break the free radical chain efficiently to inhibit the lipid peroxidation. However, the effect of tocopherol on the inhibition of membrane protein damage, exhibited by the loss of thiols and the formation of high-molecular-weight proteins, would be different depending on the site of initial radical generation.

Amidines↗

The mixture of aldehydes and hydrogen peroxide produced in the ozonation of dioleoyl phosphatidylcholine causes hemolysis of human red blood cells.

Dioleoyl phosphatidylcholine (PC) liposomes were ozonized and the ozonized liposomes were tested for their lytic potency on human red blood cells (RBC). Ozonation of PC liposomes generated approximately 1 mole equivalent of hydrogen peroxide (H2O2) and 2 mole equivalents of aldehydes, based on the moles of ozone consumed. The time necessary for 50% hemolysis induced by ozonized liposomes (a convenient measure of hemolytic activity) was found to depend on the extent of ozonation of the PC liposomes, indicating the formation and accumulation of hemolytic agents during ozonation. Hemolysis was also observed when RBC were incubated with nonanal, the expected product of the ozonation of oleic acid, the principle unsaturated fatty acid in the liposomes. Hydrogen peroxide, another product of PC ozonation, did not induce hemolysis; however, a combination of H2O2 and nonanal was significantly more hemolytic than nonanal alone. A ratio of 1:2 H2O2/nonanal (the ratio observed in the ozonized liposomes) provided hemolytic activity comparable to that observed with ozonized dioleoyl PC. Among different antioxidants tested, ascorbate, catalase, and glutathione peroxidase partially inhibited hemolysis induced by ozonized liposomes and by H2O2/nonanal mixtures, but they were not protective against the nonanal-induced hemolysis. Identification of H2O2 and aldehydes as cytotoxic chemical species generated from the ozonation of unsaturated fatty acids may have an important bearing on the in vivo toxicity of ozone on the lung as well as on extrapulmonary tissues.

Aldehydes↗

The gene expressions of macrophage colony-stimulating factor (MCSF) and MCSF receptor in the human myometrium during pregnancy: regulation by sex steroid hormones.

We investigated the biological effect of sex-steroid hormones, secreted from the corpus luteum and placenta, on the induction of mRNA encoding macrophage colony-stimulating factor (MCSF) and c-fms proto-oncogene (MCSF receptor) in the human uterine myometrium. Poly(A)+RNA was extracted from the myometrium of pregnant and non-pregnant uterine myometrium and then Northern blot analysis was performed on poly(A)+RNA. The myometrium of non-pregnant women expressed neither mRNA of macrophage colony-stimulating factor (MCSF) nor any transcript related to the c-fms proto-oncogene. On the other hand the myometrium of pregnant women expressed MCSF mRNA (4.7 kb) and two kinds of transcript related to the c-fms proto-oncogene (3.9 and 1.3 kb). The mRNAs of both MCSF and c-fms proto-oncogene were induced in the uterine myometrium of non-pregnant women under pseudopregnant therapy of mestranol and norethindrone. These results indicate that sex steroid hormone secreted from the corpus luteum of pregnancy and/or placenta may be deeply involved in the hypertrophic change of uterus during pregnancy by inducing MCSF and MCSF receptor (c-fms proto-oncogene protein product) in the myometrium.

Corpus Luteum↗

Technegas for inhalation lung imaging.

Technegas, an aerosol generator recently devised in Australia, produces aerosol particulates called 'technegas' which have characteristics of both an aerosol and a gas. The majority of the particulate is below 200 nm in size as measured by electron microscopy. Four normal subjects and 31 patients with various lung diseases were studied by imaging the lungs following inhalation of technegas. The penetration of inhaled technegas to the lung periphery was excellent; the average alveolar deposition ratio (ALDR) was 85%. Comparative studies with lung images obtained either with an ultrasonic nebulizer or jet nebulizers also confirmed better penetration of inhaled technegas to the lung periphery. There was no significant statistical difference in the ALDRs between normals and patients. Aerosol studies were comparable to perfusion counterparts, and evaluation of regional ventilatory status was greatly facilitated. Because of the large ALDR and the low airway deposition ratio (ADR), actual imaging could be done not only immediately after aerosol inhalation but also some time later without losing too much radioactivity from the lungs. One disadvantage was that technegas immediately after generation was anoxic.

Administration, Inhalation↗

Susceptibility of neonatal lipoproteins to oxidative stress.

We compared peroxidizability of neonatal and adult lipoproteins exposed to oxidative stress initiated by an azo-compound. Oxygen uptake showed a two-phase pattern, with slow oxygen uptake in the first phase and faster uptake in the second phase. During the first phase, tocopherol was consumed progressively, inhibiting lipid peroxidation by scavenging peroxy radicals. After the tocopherol concentration fell below a critical level, extensive propagation of chain oxidative reactions produced the rapid oxygen uptake in the second phase. In the first phase of neonatal lipoprotein oxidation, a faster oxygen uptake was observed and the length of this phase was shorter than in adults. The oxygen uptake rate in the second phase was smaller in the neonatal lipoproteins. In other words, neonatal lipoproteins were more susceptible to oxidative stress than were adult ones when tocopherol remained in lipoproteins, but after tocopherol depletion the reverse was true. These results were consistent with the finding that in neonatal lipoproteins the tocopherol/lipid ratio was significantly lower (length of the inhibitory phase was closely correlated to the lipoprotein tocopherol content). In addition, the average number of active bisallylic hydrogen atoms, which are considered to determine the relative susceptibility of polyunsaturated fatty acids to oxidation, was significantly smaller (oxygen uptake rate in the second phase was closely correlated to the active bisallylic hydrogen number) in neonatal lipoproteins, and the ratio of active bisallylic hydrogen to tocopherol content (which closely correlated to oxygen uptake rate in the first phase) was also significantly lower compared with the adult ratio. Under physiologic conditions, an intensive oxidation of lipoproteins sufficient to cause lipoprotein tocopherol to fall below critical levels is unlikely to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Campylobacter enterocolitis complaining of melena].

A 38-year-old man was admitted to our hospital complaining of 5 episodes of melena without abdominal pain or diarrhea. No abnormalities were noted through an upper gastrointestinal endoscopy, but a proctoscopy revealed a large amount of coagulated blood within the rectum immediately before his admission. A colonoscopy revealed spotty redness with dark-red coagulation in the region from the splenic flexure down to the rectum except oral colon beyond the transverse colon. A presumptive diagnosis of campylobacter enterocolitis was made by a microscopy performed on the stool specimen, then an oral administration of erythromycin was started. A colonoscopy done on the 5th hospital day proved improvement on the mucosal changes. The final diagnosis of campylobacter enterocolitis was made by the stool culture. The patient took a satisfactory course of hospitalization and was discharged on the 10th day. Bacteriological examination of stool specimen together with endoscopy has been confirmed to be useful for the diagnosis of melena cases without manifestation of infectious enterocolitis.

Adult↗

Vitamin E and the peroxidizability of erythrocyte membranes in neonates.

We showed the increased susceptibility of neonatal biomembranes to oxidation by a kinetic analysis using an azo compound as a free-radical initiator and red blood cell (RBC) ghosts as a model membrane. When the RBC ghosts were oxidized, oxygen consumption was suppressed during the induction period in which membrane tocopherol was consumed at a constant rate, while increased oxygen uptake was observed after the tocopherol was exhausted. The total tocopherol content was similar in cord, maternal, and adult RBC ghosts, and there were no differences in the induction period (tinh) among the three types of ghosts. While the oxygen uptake rate during the induction period (Rinh) was similar in cord and adult ghosts, the rate in the subsequent phase (Rp) was considerably faster in the cord ghosts. Fatty acid analysis in the membrane lipids showed that the active bisallylic hydrogen (active H) content was greater in cord ghosts than in adult ghosts. The active H content closely correlated with the Rp, but did not with the Rinh. The kinetic chain length (KCL), i.e., the ratio of the rate of propagation to that of initiation, was calculated from Rp and tocopherol consumption rate and KCL values were higher in cord ghosts than in adult ghosts. The faster Rp and the higher KCL of the cord ghosts were attributable to a greater active H content rather than to the tocopherol content.

Adult↗

[Voiding disturbance in elderly males examined by prostate mass screening. Gunma Urological Oncology Study Group].

Information about voiding disturbance was obtained from 34,140 elderly males in Gunma Aged Club Association (Q group) through a questionnaire and from 8,129 males by prostate mass screening for prostate disease (MS group) as to: (1) the characteristics of the subjects examined by the mass screening, (2) the relationship between the voiding disturbance and aging and (3) the frequency of voiding disturbance in the normal elderly males. In MS group, the percentage of young subjects, especially less than 60 years old, who complained voiding disturbance was higher than the expected percentage on the assumption that it increases with aging. The percentage of voiding disturbance in these young subjects was also higher than that of males in the same decade in Q group. In their past and present history, the percentage of benign prostatic hypertrophy (BPH) in these young subjects was higher than the expected percentage on the assumption that the incidence of BPH increases with aging. Judging from these results, it was estimated that they were not satisfied with the medical care by which they were treated or were being treated, and they received this mass screening to obtain consultation for their complains. Loss of the force was related with the prostate size estimated by digital rectal examination but not with aging. However, nocturia was well related with aging but not with the prostate size. Hesitancy, strain and dribbling were not apparently related with either the prostate size or aging. It was demonstrated that frequency of nocturia was 0 to 1 in less than 60 years old normal males, 0 to 2 in 60 to 79 years old ones and 0 to 3 in over 80 years old ones. The other symptoms studied in each decade were also analyzed and discussed.

Aged↗

[Clinical analysis of male urethritis].

We reviewed 497 patients with male urethritis diagnosed between January, 1986 and March, 1989 at the Asama General Hospital. The incidence of gonococcal urethritis (GU) was 47.7%, and that of non-gonococcal urethritis (NGU) 52.3%. There was no difference in the age distribution between GU and NGU. Prostitutes were the most common source of the infection in both GU and NGU. Incubation periods were longer in NGU than in GU, statistically. Urethral discharge was the most common symptom. Purulent urethral discharge was seen more commonly than serous urethral discharge in GU. On the contrary, serous urethral discharge was more common in NGU. Penicillin-resistant gonococcus comprised 29.4% and mixed infection of the C. trachomatis existed 25.6% in GU. C. trachomatis was detected in 71.8% in NGU. In GU, new quinolones and penicillins were administered frequently. The effective rates 1 week after the administration were 80.6% and 83.3%, respectively. In NGU, new quinolones and minocycline were administered frequently. The effective rates were 70.4% and 85.3%, respectively. Ofloxacin (OFLX) showed the highest effective rate to NGU among the four new quinolones. The relapse rate for the two-week administration group was lower than that for the one-week-administration group, but the difference was not statistically significant.

Adolescent↗

[Pulmonary epithelial permeability in normal subjects and patients with idiopathic interstitial pneumonia].

99mTc-DTPA is a low molecular weight substance which is believed to pass through the pulmonary epithelium when it is inhaled as an aerosol. We performed 99mTc-DTPA inhalation studies in 10 nonsmoking normal subjects and 10 patients with biopsy proven idiopathic interstitial pneumonia prior to therapy. 99mTc-DTPA aerosol was inhaled for 3 min with the subject in the supine position and radioactivity was measured anteriorly with a gamma camera and recorded on a computer. Measurements were performed for 3 min with the subject inhaling aerosol and for the subsequent 30 min with the subject in the same position. Time activity curves from the five regions of interest (ROIs) including the entire left lung, the entire right lung, and the upper, middle and lower third of the right lung were separately fitted to a single exponential function for the initial 7 min following cessation of inhalation, and the respective clearance half life (t1/2) in min was calculated. Lung function data, arterial blood gas tensions and blood chemistry were also obtained for comparison with the t1/2 values. The t1/2 values were significantly smaller in all ROIs in patients with idiopathic interstitial pneumonia than in normal subjects, indicating a increased pulmonary epithelial permeability in these patients. There was no relationship between t1/2 and %DLco, %DLco/VA, PaO2, or LDH. Although the true pathophysiologic significance of t1/2 measured using 99mTc-DTPA aerosol is still not known, we consider that this measurement may be an important indicator of nonrespiratory lung function, in particular the degree of alveolar epithelial damage.

Administration, Inhalation↗

Effect of respiratory phases and gravity on mucociliary transport in the normal lungs.

Effect of gravity and respiratory phase on mucociliary transport was studied in 11 normal subjects. After inhaling 99mTc-human serum albumin aerosol, each subject was positioned in right lateral decubitus and then supine position before a scintillation camera. Data in list mode and simultaneous respiratory curve were stored in a computer for 15 min each. The respiratory curve was sequentially marked at the beginning of inspiration, expiration and pause of each respiratory cycle and list mode data was converted into frame mode, respectively. The frame mode data was then sequentially connected according to the respective respiratory phase. The data in count-per-second from each lungs versus time was fitted to a straight line by regression analysis and the slope of the line was compared with each other for respective respiratory phase. Slopes of net radioactivity changes in the right and left lungs were compared to evaluate gravity effect. Neither respiratory phases nor gravity had any significant effect on mucociliary transport. Theoretical calculations have also supported the present findings.

Adult↗

Resonance energy transfer between points in a reconstituted skeletal muscle thin filament. A conformational change of the thin filament in response to a change in Ca2+ concentration.

The spatial relationships between Lys-61, Cys-374 on actin or SH1 on myosin subfragment-1 (S1) and Cys-190 on tropomyosin or Cys-133 on troponin-I (TnI) in a reconstituted thin filament were studied by fluorescence resonance energy transfer. 5-(2-Iodoacetylaminoethyl)aminonaphthalene 1-sulfonic acid (IAEDANS) attached to Lys-190 on tropomyosin or to Cys-133 on TnI was used as a donor. Fluorescein 5-isothiocyanate (FITC) attached to Lys-61 or 5-(iodoacetoamido)fluorescein (IAF) attached to Cys-374 on actin and 4-dimethylaminophenyl-azophenyl 4'-maleimide (DABMI) attached to SH1 on S1 were used as an acceptor. The transfer efficiency between AEDANS attached to Cys-190 on tropomyosin and FITC attached to Lys-61 on actin was 0.42 in the absence of troponin, 0.46 in the presence of troponin and Ca2+ and 0.55 in the presence of troponin and absence of Ca2+. The corresponding distances between the probes were calculated to be 4.7 nm, 4.6 nm and 4.3 nm respectively, assuming a random orientation factor K2 = 2/3. A large difference in the transfer efficiency from AEDANS attached to Cys-133 on TnI to FITC attached to Lys-61 on actin was observed between in the presence (0.52) and absence (0.70) of Ca2+. The corresponding distances between the probes were calculated to be 4.5 nm in the presence of Ca2+ and 3.9 nm in the absence of Ca2+. The distance between Cys-190 on tropomyosin and Cys-374 on actin was measured to be 5.1 nm and the transfer efficiency (0.35) did not change upon addition of troponin whether Ca2+ is present or not, in agreement with the previous report [Tao, T., Lamkin, M. & Lehrer, S. S. (1983) Biochemistry 22, 3059-3064]. The distance between Cys-133 on TnI and Cys-374 on actin was measured to be 4.4 nm. No detectable change in transfer efficiency (0.58) was observed between values in the presence and absence of Ca2+. These results suggest that a relative movement of the two domains of actin monomer in a reconstituted thin filament occurs in response to a change in Ca2+ concentration. The transfer efficiencies between DABMI attached to SH1 on S1 and AEDANS attached to Cys-190 on tropomyosin or Cys-133 on TnI were too small (less than 2%) for an accurate estimation of the distances, suggesting the distances are longer than 7.3 nm.

Actins↗

Interaction of F-actin-AMPPNP with myosin subfragment-1 and troponin-tropomyosin: influence of an extra phosphate at the nucleotide binding site in F-actin on its function.

An unsplitable analogue of ATP (adenylyl imidodiphosphate; AMPPNP) was incorporated into F-actin [Cooke, R. (1975) Biochemistry 14, 3250-3256]. The resulting polymers (F-actin-AMPPNP) activated the ATPase activity of myosin subfragment-1 (S1) as efficiently as normal F-actin; neither the maximum velocity at infinite actin concentration (Vmax) nor the affinity of actin to S1 in the presence of ATP (1/KATPase) changed, which indicates that the terminal phosphate of the bound nucleotide at the cleft region between the two domains of the actin molecule [Kabsch, W., Mannherz, H.G., & Suck, D. (1985) EMBO J. 4, 2113-2118] is not directly involved in a myosin binding site. However, the interaction of F-actin with troponin-tropomyosin was strongly modulated by the replacement of ADP with AMPPNP. The troponin-tropomyosin complex strongly enhanced the activation of S1-ATPase activity by F-actin-AMPPNP in the presence of Ca2+, although it has no effect on the activation by normal F-actin-ADP. KATPase was enhanced about threefold by troponin-tropomyosin in the presence of Ca2+, while Vmax was not markedly changed. F-actin-AMPPNP is highly potentiated by troponin-tropomyosin even with low S1 to actin ratios and at high ATP conditions. In the absence of Ca2+, the activation by F-actin-AMPPNP was inhibited normally by troponin-tropomyosin. The results suggest that the terminal beta-phosphate of the bound nucleotide in F-actin is located in a region which is important for regulation of the interaction with myosin.

Actins↗

Does a beta 2-stimulator really facilitate mucociliary transport in the human lungs in vivo? A study with procaterol.

The purpose was to study whether procaterol, a beta 2-stimulator, facilitated mucociliary transport on the ciliated airways in the human lungs. From immediately after inhalation of [99mTc]albumin aerosol, radioactivity of the thorax was continuously measured anteriorly by a gamma camera with the examinee in the supine position; the data were sequentially stored in a computer in 10-s frame mode. Three puffs (30 micrograms) of procaterol were inhaled from a metered dose inhaler at 60 min in the same supine position, and measurement of radioactivity was continued for 30 min more. Spirometry was performed before and after the measurement of radioactivity. A group of 8 normal subjects and 34 patients with various lung diseases, including 6 with bronchial asthma in remission, were studied. In addition to observation of mucus transport on the large airways by radioaerosol inhalation lung cinescintigraphy, the time-activity curve from the right lung was evaluated and the quantitative parameters for evaluating mucociliary clearance were calculated for the right lung. Following inhalation of procaterol, there were neither significant acceleration in mucus transport on the large airways by cinescintigraphy nor significant changes in the slope of time-activity curves. Quantitative parameters did not show any significant changes either, although spirometry indicated significant bronchodilation. We conclude that three puffs of inhaled procaterol neither necessarily accelerate mucus transport nor facilitate mucociliary clearance in the human lung.

Administration, Inhalation↗

Adipose tissues and vitamin E.

1. Vitamin E content in the adipose tissue was examined in rats with and without vitamin E deficiency. With the progression of vitamin E depletion, the more rapid decrease in tocopherol concentration was observed in brown adipose tissue (BAT) than in white adipose tissue (WAT), and the rate of decrease of tocopherol was approximately three times faster in BAT than in WAT. After the intramuscular administration of 10 mg/kg of all-rac-tocopheryl acetate twice a week for two weeks to vitamin E-deficient rats, a similar pattern of increase was observed in the tocopherol concentrations of BAT and WAT, although the rate of increase was slower in WAT than in BAT. 2. Changes of tocopherol concentration in BAT and WAT were investigated in normo-nourished rats with hyperlipemia produced by the intramuscular injection of Triton WR-1339 for 7 days. A marked increase in tocopherol concentration was observed in both BAT and WAT in the late period of hyperlipemia, with the increase being greater in WAT. 3. The fatty acid composition of adipose tissue was compared between rats with and without vitamin E deficiency. No significant differences were observed in BAT and WAT between the two groups. 4. The glucose uptake of WAT was not altered in vitamin E-deficient rats when compared with control rats.

Adipose Tissue↗

[Treatment of asynchronous bilateral renal cell carcinoma. On our experience of enucleation for two cases].

In patients with either bilateral renal malignancies or with carcinoma occurring in a solitary kidney, the principle of en bloc removal of the tumor-bearing kidney cannot be applied. Recently we have performed surgical enucleation in two cases of asynchronous bilateral renal cell carcinoma. Case 1. A 60-year-old woman was hospitalized with diagnosis of left renal tumor 10 years tumor 10 years after right nephrectomy for renal cell carcinoma. The tumor was enucleated while occluding the renal vessels. Pathological examination revealed that the tumor (a nodule of 35 g) was renal cell carcinoma of grade I and perfectly covered by pseudocapsule. Hemodialysis was not required. The patient has been well for more than 11 months postoperatively and Ccr is 65 ml/min. Case 2. A 62-year-old man with slight elevation of serum GOT and GPT level was examined by CT, which revealed a space occupying lesion in the left kidney. He had undergone nephrectomy for renal cell carcinoma of right kidney 11 years ago. Three nodules of 56 g, 6 g and 3 g were removed by in situ enucleation. They were renal cell carcinoma of grade II and there was no malignant penetration of the pseudocapsule pathologically. After surgery hemodialysis was required 10 times for 21 days. Renal function has been refined gradually and the patient is well with 47.3 ml/min of Ccr at 4 months postoperatively. Before this report of 2 cases there were 22 cases of asynchronous bilateral renal cell carcinoma in Japanese literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Renal Cell↗

[Prognostic factor for prostate cancer. Gunma Urological Oncology Study Group].

The study of prognostic factors in patients with prostate cancer (Pca) may be of value in understanding the natural history of the disease and may also assist in planning and analyzing the results of clinical trials. Moreover some information through this study would be beneficial to assessing the prognosis and decision of better therapy form of individual patients. The significance of items studied was evaluated from the two view points, survival rate and Pca death rate. Stage, pathological differentiation and acid phosphatase were significantly related to them, in the category grade depending manner. Past history and complication, and age were also significantly related to them but higher category grade as a survival factor showed lower Pca death rates. ESR, gait disturbance and hematuria were related to only survival rate. Any significant relationship was not observed in serum testosterone, voiding disturbance and cancer-pain. Prognostic factors should be clinically used through the well understanding of each characteristics. This paper also showed that statistical significance not always provide a wide difference between categories compared.

Age Factors↗