Seyed Mohammad Mirbod

Reduced mastication stimulates impairment of spatial memory and degeneration of hippocampal neurons in aged SAMP8 mice

The involvement of reduced mastication in senile dementia was evaluated by examining the effect of cutting off the upper molars (molarless) on spatial memory and numbers of hippocampal neurons in aged SAMP8 mice. Molarless mice showed a decrease in both learning ability in a water maze and neuron density in the hippocampal CA1 region compared with control mice. These changes increased the longer the molarless condition persisted. The data suggest a possible link between reduced mastication and hippocampal neuron loss that may be one risk factor for senile impairment of spatial memory.

Subjective complaints in orthopedists and general surgeons

The aim of this study was to investigate the prevalence of subjective complaints among two groups of health care personnel. Using a mail questionnaire, 63 male orthopedists and 78 male general surgeons were asked to respond to questions on their subjective musculoskeletal complaints as well as their age, occupational career, and daily working time. In the final analysis, 54 orthopedists and 63 general surgeons who were aged ⩽ 59 years and had worked for at least 5 years in clinical practice were considered. The mean age was 43.3 (SD 7.6) years for the orthopedists and 41.8 (SD 9.5) years for the general surgeons. Their mean employment time was 18.1 (SD 8.9) years and 16.6 (SD 9.5) years, respectively. The average working time per day was 9.5 h. In general, the orthopedists had a higher prevalence of subjective complaints than the general surgeons. Problems in the shoulders and lower back were the most frequently reported complaints, followed by neck problems. There were significant differences (P < 0.05) between the two groups regarding stiffness in the shoulders, stiffness in the lower back, pain in the neck, and numbness in the fingers. When subjective complaints were compared between the junior (employment time: < 20 years) and senior (employment time: ⩾ 20 years) staff, the junior orthopedists had significantly higher prevalence rates for stiffness in the shoulders, pain in the neck, and stiffness in the lower back. This subgroup had significantly higher odds ratios (ORs) for some subjective complaints as compared to the junior surgeons, e.g., pain in the neck [OR = 6.19, 95% confidence interval (95% Cl) 1.91–20.04], shoulder stiffness (OR = 3.75, 95% Cl 1.36–10.31), pain in the shoulders (OR = 4.41, 95% Cl 3.64–4.70), and stiffness in the lower back (OR = 4.93, 95% Cl 1.74–13.94). It was concluded that ergonomic intervention to improve the working environment is imperative. In addition to ergonomic factors, consideration might also be given to psychological factors with a view to reducing the risk of subjective complaints among these subjects.

Effects of long-term moderate exercise and increase in number of daily steps on serum lipids in women: randomised controlled trial [ISRCTN21921919]

BackgroundThis study was designed to evaluate the effects of a 24-month period of moderate exercise on serum lipids in menopausal women.MethodsThe subjects (40–60 y) were randomly divided into an exercise group (n = 14) and a control group (n = 13). The women in the exercise group were asked to participate in a 90-minute physical education class once a week and to record their daily steps as measured by a pedometer for 24 months.ResultsMean of daily steps was significantly higher in the exercise group from about 6,800 to over 8,500 steps (P < 0.01). In the control group, the number of daily steps ranged from 5,700 to 6,800 steps throughout the follow-up period. A significant interaction between the exercise group and the control group in the changes og total cholesterol (TC), high-density lipoprotein cholesterol (HDLC) and TC : HDLC ratio could be observed (P < 0.05). By multiple regression analysis, the number of daily steps was related to HDLC and TC : HDLC levels after 24 months, and the changes in TC and HDLC concentrations.ConclusionsThese results suggest that daily exercise as well as increasing the number of daily steps can improve the profile of serum lipids.

Prevalence of Raynaud's phenomenon in different groups of workers operating hand-held vibrating tools

In eight groups of subjects operating various hand-held vibrating tools and aged from 30 to 59 years, the prevalence rates of vibration-induced white finger (VWF) and numbness, pain, or stiffness in the upper and lower extremities were investigated. Hand-transmitted vibration levels (HTVLs) were measured on the back of the hand, by means of unidirectional (x-axis) vibration dosimeters, and the frequency-weighted acceleration levels [(Lh,w)eq,t] were determined as the vibration levels. The prevalence rates of VWF and numbness of the hands in these subjects were compared to the prevalence rates of Raynauds phenomenon (RP) and numbness of the hands in 1027 males and 1301 females not occupationally exposed to vibration (age range: 30–59 years). It was observed that in subjects exposed to HTVLs of between 1.1 and 2.5 m/s2, the prevalence of VWF was between 0.0% and 4.8%. The prevalence of VWF reached 9.6% in a group of workers exposed to HTVLs of 2.7–5.1 tn/s2. The latter group showed a significant difference (P < 0.05) in the prevalence of VWF compared to the 2.7% prevalence of RP in male subjects of the general population. The prevalence of VWF in female subjects exposed to vibration (4.3%) was not significantly different from the prevalence of RP in females of the general population (3.4%). The prevalence rates of numbness of the hands were in the range of 6.5%–30.4% in the exposed groups and in the range of 13.4%–29.5% in the general population. Among the subjective symptoms, only VWF showed a significant positive correlation with HTVLs (R2 = 0.5, P < 0.05). It was concluded that in decisions concerning quantitative recommendations for vibration exposure, the prevalence of VWF should be employed. With a view to decreasing the risk of developing VWF, estimated vibration safety values for 4 h and 2 h daily exposures are discussed.

Cutaneous signs (Raynaud's phenomenon, sclerodactylia, and efladema of the hands) and hand-arm vibration exposure

SummaryDermatological tests and examinations of the hand(s) were carried out in vibration-exposed and un exposed males. The subjects were 179 chain-saw workers in private forestry companies and 205 local inhabitants who had never used vibrating tools. The prevalences of Raynauds phenomenon (RP), sclerodactylia, and edema of the hands were estimated in both groups, and associations between these cutaneous signs and vibration exposure were evaluated. The prevalences of RP and edema in the exposed group were 9.5% and 1.7%, respectively, and in the unexposed group, 2.9% and 1.5%, respectively. Sclerodactylia was seen in 31.8% of the chain-saw workers but in only 6.4% of the unexposed individuals. In statistical analyses based on unconditional logistic regression models with adjustment for age, RP was associated with long-term (≥ 20 years) vibration exposure [odds ratio (OR) = 7.06; 95% confidence interval (CI) = 2.51−19.87]. Sclerodactylia was associated with both short- and long-term vibration exposure (OR = 6.54, Cl = 3.30-13.36; OR = 7.05; CI = 3.41-14.60, respectively). There were significant dose-response relationships between RP and duration of exposure and between sclerodactylia and duration of exposure. Results of function tests indicated a longer recovery time and a higher vibration threshold for the workers with RP. The presence of sclerodactylia, however, did not have any significant influence on function test results. It is possible to conclude that not only RP but also sclerodactylia could be induced by vibration exposure. However, most cases of sclerodactylia were not so serious as to involve disturbances of peripheral circulatory and nerve function.

PREVALENCE OF RAYNAUD'S PHENOMENON AND SPECIFIC CLINICAL SIGNS RELATED TO PROGRESSIVE SYSTEMIC SCLEROSIS IN THE GENERAL POPULATION OF JAPAN

Background. In order to evaluate the prevalence rates of Raynauds phenomenon (RP) and specific clinical signs related to progressive systemic sclerosis (PSS) in the general population of Japan, inquiries were made concerning RP in the hands and dermatologic examinations were also conducted.

Effects of Maharishi Amrit Kalash 5 as an Ayurvedic herbal food supplement on immune functions in aged mice.

BackgroundMaharishi Amrit Kalash (MAK) 5, one of the Ayurvedic food supplements, belongs to a group of substances known as Rasayana. MAK5 and other Rasayanas are believed to enhance the bodys resistance to infections and disease, and enhance longevity. In this study, we determined the effects of administration of MAK5, one of the Ayurvedic food supplements on immune functions in young and old mice.MethodsMale C3H/He N mice were divided into five groups: two no treatment groups (old control: 22-month-old and young control: 2-month-old) and three MAK5 treated groups with differing dose of MAK5. MAK5 was given p.o. at 50 mg/kg, 100 mg/kg or 200 mg/kg per day (3 days/week) for 2 months.ResultsWe found that glucose consumption of peritoneal macrophages from old mice treated with MAK5 at all doses and incubated for 48 and 72 h were significantly greater than that in the control group. Nitric oxide production of peritoneal macrophages stimulated by lipopolysaccharide (LPS) in old mice treated with MAK5 at all doses was significantly greater than that in the old control group, but not compared to the young control group. Stimulation index (S.I.) in old mice gavaged with MAK5 at all doses was significantly higher than that in the old control group. IL-2 production stimulated by Con A in old mice given MAK5 at all doses was significantly higher than that in the old control group. Production of IFN-γ stimulated by Con A in old mice given MAK5 at doses of 100 mg/kg and 200 mg/kg were significantly higher than that in the old control group. IL-4 production of splenic lymphocyte stimulated by Con A in old mice given MAK5 at dose levels of 100 and 200 mg/kg were significantly higher than that in the old control group.ConclusionThe results suggest that MAK5 suppressed the age associated glucose consumption of peritoneal macrophages and cellular immune function reduction, and that it contributes to the prevention of the immunosenescence.

Enhanced macrophage functions and cytokine production of lymphocytes after ingestion of bon narine in female BALB/c mice.

The purpose of this investigation was to determine the effects of bon narine treatment on macrophage and lymphocyte functions in mice. Twelve week-old female inbred BALB/c mice were given bon narine p.o. at 30 mg/kg per day and sacrificed after three months. Glucose consumption of peritoneal macrophages in the bon narine treated group during incubation up to 72 h was significantly higher than that in the control group. Activities of acid phosphatase (APH), beta-glucuronidase (GLU) and lactate dehydrogenase (LDH) in the peritoneal macrophages in the bon narine treated group significantly increased compared to that in the control group. Macrophage production of nitric oxide stimulated by lipopolysaccharide (LPS) in the bon narine treated group was significantly increased. Interleukin-1beta (IL-1beta) production of peritoneal macrophages stimulated by LPS was significantly higher in the bon narine treated group. Stimulation indices in splenic lymphocytes by concanavalin A (Con A) in the bon narine treated group were significantly higher than that in the control group. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production stimulated by Con A were significantly increased in the bon narine treated mice. Interleukin-4 (IL-4) production of splenic lymphocytes stimulated by Con A was not different in the control group and the bon narine treated group. These findings might suggest that oral administration of bon narine effectively enhanced the macrophage function and lymphocyte responsiveness in mice.

Subjective symptoms among female workers and winter working conditions in a consumer cooperative.

Subjective Symptoms among Female Workers and Winter Working Conditions in a Consumer Cooperative: Ryoichi Inaba, et al. Deparatment of Occupational Health, Graduate School of Medicine, Gifu University—Subjective musculoskeletal symptoms are more frequently complained about in cold store work and in related conditions than in normal temperature work. This cross sectional study was undertaken (a) to explore the prevalence of subjective symptoms in winter among a group of female workers engaged in classification of cold storage goods, and in a group of female checkers in several supermarkets of a large consumer cooperative; and (b) to give recommendations for improving the winter working conditions of these workers. The subjects consisted of 46 workers engaged in classification of cold storage goods, 56 checkers operating a laser scanner in supermarkets and 59 office workers (control group). Work loads for the three groups were estimated according to the recommended criteria. A self‐administered questionnaire covering age, occupational career, smoking, alcohol drinking and physical exercise, present or past history of diseases, individual protective measures against cold, and subjective symptoms (54 items) was used. The air temperature of the working site at the opening time for classification workers was 4.8° C which was significantly lower than those measured for the other two work places (12.1°C and 15.8°C). About 70 to 80% of classification workers complained of cold sensation in different body regions, as well as shoulder stiffness, and problems related to the back. The supermarket checkers and office workers had a high prevalence of cold sensation in their feet. The frequencies of using warm clothes and foot heaters, as an individual measure to work comfortably in winter among the classification workers and the checkers were significantly higher than that among the office workers. We concluded that work difficulty due to moderate cold exposure among workers in the consumer cooperative could be reduced by some physical activity as well as proper clothes.

Pathophysiology of Vibration-Induced White Finger and Safety Levels for Hand-Transmitted Vibration

Pathophysiology of Vibration‐Induced White Finger and Safety Levels for Hand‐ Transmitted Vibration: Ryoichi Inaba, et al. Department of Hygiene, Gifu University School of Medicine—This review addresses the pathogenic mechanism and vibration safety values of vibration‐ induced white finger (VWF). Sympathetic hyperactivity alone has long been postulated to account for VWF, but damage to vasoregulatory structures and functions in the finger skin now also seems to be involved. The physiological complexity of the response to cold is so great and the interaction between various vasoregulatory mechanisms so intricate that only a multifactorial etiology and pathogenesis is likely for VWF. These factors will be discussed in detail. Regarding vibration safety values, the prevalence of VWF and vibration magnitude (hand‐transmitted vibration levels (HTVLs)) in various groups of workers which reported in our previous studies were reviewed. The prevalence rates of VWF were compared to the prevalence rates of Raynauds phenomenon (RP) in a large group of males and females without vibration exposure. It was observed that in subjects exposed to HTVLs of between 1.1 and 2.5 m/s2, the prevalence of VWF was 0.0‐4.8%. The prevalence of VWF in workers exposed to HTVLs of up to 5.1 m/s2 was 9.6% and significantly higher than the prevalence of RP in males in the general population (2.7%). A significant positive correlation between VWF and HTVLs values was obtained. By employing the results obtained on vibration magnitude and the prevalence of VWF, estimated vibration safety levels are discussed.