Changes in myocardial myosin heavy chain isoform composition with exercise and post-exercise cold-water immersion.

This study investigated the changes in myocardial myosin heavy chain (MHC) isoforms, MHC-α and MHC-ß composition in young healthy rodents following endurance training, with and without post-exercise cold-water immersion (CWI). Male rats were either trained on a treadmill for 10 weeks with (CWI) or without (Ex) regular CWI after each running session, or left sedentary (CON). Left ventricular mRNA of MHC-α, MHC-ß, thyroid receptor α1 (TR-α1) and ß (TR-ß) were analyzed using rt-PCR and semiquantitative PCR analysis. MHC isoform protein composition was determined using SDS-PAGE electrophoresis. MHC-α isoform protein was predominant in all groups. The relative expression of MHC-ß (%MHC-ß) protein was not different between groups (CWI 34.7 ± 6.9%; Ex 32 ± 5.3%; CON 35.5 ± 10%; P = 0.7). MHC-ß mRNA was reduced in Ex (0.7 ± 0.3-fold) compared to CWI (1.3 ± 0.2-fold; P < 0.001) and CON (1.01 ± 0.2-fold; P = 0.03). TRα1 mRNA was lower in CWI (0.4 ± 0.05-fold) than Ex (1.02 ± 0.3-fold) and CON (1.01 ± 0.2-fold) (P < 0.001 for both). CWI exhibited greater %MHC-ß mRNA (56.8 ± 4.1%) than Ex (44.4 ± 7.7%; P = 0.001) and CON (48.5 ± 7.8%; P = 0.03). Neither exercise nor post-exercise CWI demonstrated a distinct effect on myocardial MHC protein isoform composition. However, CWI increased the relative expression of MHC-ß mRNA compared with Ex and CON. Although this implicates a potential negative long-term impact of post-exercise CWI, future studies should include measures of cardiac function to better understand the effect of such isoform mRNA shifts following regular use of CWI.

Intra-arterial infusion of leptin does not affect blood pressure in salt-loaded rabbits.

The aim of this research is to see the effect of intra-arterial infusion of leptin on blood pressure of salt loaded rabbits in vivo. Increased blood pressure was produced in rabbits by giving diets containing 8% sodium chloride for 5 weeks. Leptin in different concentrations was infused intra-arterially into rabbits fed on high salt diets and the response was compared in rabbits fed with low salt diets. High salt diets produced significant increase in blood pressure. In rabbits fed with low salt diet, leptin infused intra-arterially caused an increase in blood pressure while infusion of leptin into rabbits fed with high salt diets does not affect the blood pressure. In conclusion, salt loading to rabbits abolishes the effect ofleptin on cardiovascular system. This may indicate that leptin effect on sympathetic activity is altered by high salt diets in these animals.

Prevalence of mistreatment and justice of grading system in five health related faculties in Jordan University of Science and Technology.

BACKGROUND: Many Jordanian university students complain of the behavior of some teaching staff. Also, they complain of the grading systems in universities. AIM: This study concerns the occurrence of different forms of student mistreatment and student mistrust of the grading system in the Jordan University of Science and Technology (JUST) as an example of universities in Jordan. METHOD: A total of 500 students in five health related faculties in JUST responded to a questionnaire. RESULTS: Our results were as follow: (i) 61% of the students had experienced at least one form of mistreatment; (ii) perceived mistreatment most often (52%) had taken the form of psychological mistreatment (shouting and humiliation); (iii) other forms of mistreatment such as physical harm (32%), mistreatment related to religion (36%), mistreatment related to external appearance (35%), sexual harassment (33%) and mistreatment related to specialty (29%) were also common; (iv) with the exception of mistreatment related to specialty which was high among the nursing students, perceived mistreatment did not vary significantly between the different faculties; (v) the male students (66%) complain more than female students (56%); (vi) perceived mistreatment was exceptionally high among the Israeli Arabs, 83% compared to 59% for the Jordanians and 65% for other non-Jordanian Arabs; (vii) fellow students (44%), professors (37%) and laboratory technicians (19%) were cited as major sources of mistreatment. Many students (66%) believe that grading system in JUST is unfair. Ninety seven percent of the Israeli Arabs did not trust the grading system compared to 64% of the Jordanians and 66% of the non-Jordanian Arabs. CONCLUSIONS: This study suggests that, feelings of mistreatment among university students is strong while their trust of the university grading system is low. Perceived mistreatment and an unfair grading system may be a major source of stress among our students and may affect the process of teaching and learning in our country. This should alert the university administration to face these issues and try to solve them.

Serum levels of sex hormones in men with acute myocardial infarction.

OBJECTIVE: To compare the serum levels of total testosterone(TT), free testosterone (FT), estradiol, sex hormone binding globulin (SHBG), and androstenedione (AS) in patients with acute myocardial infarction (AMI) at the time of hospitalization, patients with old myocardial infarction (OMI), and patients with normal coronary arteries (NC) admitted for diagnostic coronary angiography. METHODS: Serum sex hormones and lipid profile were measured in 79 male patients; 30 patients with AMI, 21 patient with OMI and 28 patients with NC. Ages ranged from 33-68 years. Androstenedione, estrogen, both total and free testosterone levels were quantified using coat-a-count radioimmunoassay kits. Sex hormone binding globulin was analyzed using immunoradiometric assay (IRMA)-count kits. RESULTS: The levels of serum estradiol in the AMI were significantly higher and serum levels of TT, FT, and SHBG were significantly lower in AMI than in OMI and NC but there was no difference found for the levels of AS in all groups. Estradiol level was also higher in OMI than in control group but no significant changes found for other sex hormones in OMI and control group. Also triglyceride, high density and low density lipoprotein in AMI were significantly different from that in OMI and control groups. CONCLUSIONS: Serum estradiol and low density lipoprotein levels are increased but TT, FT and SHBG levels are decreased in men with AMI compared with patients with NC.

Serum sex hormones in premenopausal women with coronary heart disease.

OBJECTIVES: The objectives of this study were to investigate the relationship between the incidence of coronary heart diseases in premenopausal women and plasma level of total and free testosterone, estrogen, androstenedione and sex hormone binding globulin with coronary risk factors: fasting plasma concentration of glucose, triglyceride, total cholesterol, high and low density lipoproteins. METHODS: The study was conducted in Faculty of Medicine, Jordanian University of Science/Irbid Jordan and Technology and department of cardiology in Queen Alia Heart Institute/Amman Jordan during the period from April 2003 to March 2004. Serum sex hormones levels were measured in fifty-three premenopausal women; 25 women with coronary heart disease who had hypertension and/or diabetes mellitus and 28 women without coronary heart disease. Ages ranged from 34 to 48 years. Blood samples were collected just before performing coronary angiography and serum was obtained and frozen at -70 degrees C until use. RESULTS: We found that the mean triglyceride, fasting blood sugar total cholesterol, and low density lipoprotein concentration were significantly higher in coronary heart disease patients than in patients with normal coronaries. We also found that the low levels of sex hormone binding globulin and high levels of free testosterone are associated with development of coronary heart disease. No significant correlation could be established between other plasma sex hormones level and coronary heart disease. CONCLUSION: In young women, in the presence of coronary risk factors and normal level of serum estrogen, the high levels of serum free testosterone and low levels of serum sex hormone binding globulin are associated with development of atherosclerosis and increased incidence of coronary heart disease.

High frequency of suboptimal serum vitamin B12 level in adults in Jordan.

OBJECTIVE: To assess the prevalence of functional vitamin B12 deficiency status in an adult Jordanian seemingly healthy population. METHODS: We carried out this study in the Department of Physiology, Faculty of Medicine, Jordanian University of Science and Technology, Jordan from September 2004 to January 2005. We included a randomly selected sample of 216 healthy adult volunteers (male 124, female 92, aged 19-50 years) from north Jordan. We carried out the measurement of hematological variables by Micros 60-OT Analyzer. We measured the serum vitamin B12 by microparticle enzyme immunoassay and serum folate by ion-capture assay on an AxSYM Analyzer. RESULTS: We found suboptimal (<222 pg/ml) serum levels of vitamin B12 in 104 (48.1%) (male 64, female 40) subjects. The mean serum vitamin B12 level of male in all volunteers was 238.8 +/- 97.3 pg/ml, not significantly different (p=0.24) from that of female (261.8 +/- 101.6 pg/ml). The mean serum values of vitamin B12 of male in the suboptimal group (168.3 +/- 36.4 pg/ml; range 90-221) were not significantly different from that of female (178.2 +/- 27.5 pg/ml; range 113-217) (p=0.31). Of the suboptimal group, 30 subjects (28.8%) had hyper-segmented neutrophils, 38 subjects (36.5%) had low mean corpuscular volume and 8 subjects (7.7%) had sub-optimal serum folate levels. CONCLUSION: This study revealed that there was a high frequency of suboptimal serum vitamin B12 level, which is an early sign of negative B12 balance.