Malondialdehyde and nitric oxide behaviour in patients with myocardial infarction

INTRODUCTION AND OBJECTIVES: The aim of this study was to determine the potential usefulness of malondialdehyde and nitric oxide as sensors of metabolic damage produced during acute coronary ischaemics events. METHODS: Serum malondialdehyde and nitric oxide levels were determined as thiobarbituric acid derivative and nitrites respectively in 15 male patients who were admitted to the emergency ward of the Hospital General del Sur de Maracaibo, because of acute stage of myocardial infarction. RESULTS: Our results show, upon follow-up and afterwards 30 days a highly significant increase in the malondialdehyde level during the acute phase of myocardial infarction (1.87 +/- 0.29 vs 45.47 +/- 8.67 mM; p < 2.01 10-5) that returns to normal levels 30 days after myocardial infarction when compared with healthy subjects of the same age (1.87 +/- 0.29 vs 4.58 +/- 1.43 mM). As for nitric oxide, levels also increased significantly during the acute phase of myocardial infarction (41.25 +/- 3.59 vs 164.63 +/- 12.7, p < 2.13 10-10 mM) and diminished significantly when compared with healthy adults of the same age 30 days after the acute event (41.25 +/- 3.59 vs 40.85 +/- 4.50 mM). CONCLUSIONS: Our results show that serum levels of malondialdehyde and nitric oxide increased significantly during acute infarction, coming back to normal levels 30 days after infarction, which suggest that both substances are potential tools to predict cardiac function recovery.     

Listeria Pneumonitis: Influence of Route of Immunization on Resistance to Airborne Infection

Mice that are immunized with an airborne inoculum of BCG are more highly resistant to airborne challenge with Mycobacterium tuberculosis than are mice that are immunized by the subcutaneous or intravenous route. To discover whether this phenomenon is peculiar to tuberculosis, we studied the influence of the route of immunization upon pulmonary resistance in Listeria monocytogenes infection. Mice were immunized by the airborne, intravenous, or footpad route and were subsequently challenged by the same route at 1 to 4 weeks after immunization. Mice were highly and uniformly resistant to intravenous challenge, regardless of the route of immunization. The route of immunization bore no influence upon resistance to footpad infection, but resistance was appreciably better in mice challenged within 2 weeks of immunization than it was at later time points. In mice immunized by the footpad and intravenous routes, the pattern of resistance to airborne and footpad challenges was similar, in that there was substantially less immunity at 4 weeks than at 2 weeks after immunization. However, mice immunized by the airborne route were highly resistant to airborne challenge, regardless of the interval between immunization and reinfection. In this last respect, resistance of the lungs to reinfection was similar after Listeria and tuberculosis pneumonitis. It is suggested that a similar pattern of resistance may prevail in pneumonitis caused by other facultative intracellular parasites.     

Multicenter retrospective study of implants loaded with functional prostheses 8 weeks after insertion

A multicenter retrospective statistical study was carried out to evaluate whether functional prosthetic loading of an implant 8 weeks after surgical insertion is acceptable clinically. Based on studies in vitro, which confirm that the fastest and best quality bone healing occurs around implants with surface treatment specifically after sanding with Al2O3 and subsequent passivity, this knowledge was applied to clinics. Four hundred and fifteen implants were inserted in 128 patients regardless of the pathology they presented and the quantity or quality of the area of the bone to be treated. Thus, all patients were included in the study independent of their physiological and pathological characteristics. The area of implant insertion, the type of prosthesis used, and the rate of success or survival of implants with bone resorption or mucositis were evaluated. With respect to the total number of implants loaded at 8 weeks, the rate of success for completely successful implants was 95.38%, and the rate of success of both partially and completely successful implants was 99.75%. Functional prosthetic loading at 8 weeks is an appropriate procedure, providing that technology of the implant surface guarantees, once the time has passed, that the osteointegration is achieved and capable of holding loading.     

Power spectra of sternocleidomastoids, splenius capitis, and upper trapezius in oblique exertions.

BACKGROUND CONTEXT: There is relatively little known concerning the spectral profile of the cervical muscles, despite the fact that neck injury and pain are quite prevalent. PURPOSE: The objective of the study was to calculate and study the power spectral characteristics of the sternocleidomastoids, splenii capitis and upper trapezii in anterolateral flexion and posterolateral extension in a ramp contraction. STUDY DESIGN/SETTING: In a laboratory setting experiments were conducted to record surface electromyographic (EMG) data from six cervical muscles and power spectral variables obtained. PATIENT SAMPLE: Forty normal and healthy young adults (21 men, 19 women). OUTCOME MEASURES: Power spectral of EMG signals. METHODS: EMG data for the left and right isometric anterolateral flexion and posterolateral extension were acquired from the sternocleidomastoids, splenii capitis and upper trapezius bilaterally. The subjects were seated in an upright posture and exerted left and right anterolateral flexor and posterolateral extensor efforts from rest to their maximal voluntary contraction in a gradual linear ramp fashion using visual feedback as a guide. The force exerted and the surface EMG data were sampled at 1 kHz at every 10th percentile grade of contraction and the EMG data were subjected to the Fast-Fourier transform analysis. The median frequency (MF), mean power frequency (MPF), peak power and total power of all six cervical muscles were analyzed. RESULTS: In the anterolateral flexion the ipsilateral sternocleidomastoid and splenius capitis had a wider band of frequency, which further widened with increasing grade of contraction. The trapezius did not engage in the same manner or to the same magnitude. The MF of the sternocleidomastoid in the anterolateral flexion in both genders progressively increased, the splenius capitis remained relatively unchanged, and the upper trapezius declined with the increasing grades of contraction. CONCLUSIONS: There is no significant difference between the genders in spectral profile. There is a bilateral symmetry in spectral profile with reference to activity; however, they are significantly different in different activities for the same muscles. With increasing magnitude of contraction power, spectral density distribution increases and the median frequency decreases. These results can serve as a useful reference for painful necks. Restoration of power spectral characteristics may indicate normalcy, which cannot be gleaned by other EMG or force variables.     

Effect of cigarette smoking on the oxidant/antioxidant balance in healthy subjects

BACKGROUND AND PURPOSE: Cigarette smoking has been associated with the development of cardiovascular disease and cancer. Even though the molecular mechanism(s) are not clear, the pathology has been related to oxygen free radicals present in cigarette smoke. Thus, the main objective of this study was to establish the changes in the oxidation/antioxidation balance induced by cigarette smoking. METHODS: Thirty healthy subjects (15 smokers and 15 nonsmokers) of both sexes were studied. The smokers group had smoked a mean of 14 cigarettes per day for an average of 4.5 years. Fasting serum levels of malondialdehyde (MDA), a marker of oxidative stress, nitric oxide (NO), reduced glutathione (GSH), and vitamin C (ascorbic and dehydroascorbic acids) were measured. RESULTS: Fasting NO concentration was significantly higher in smokers (51.3 +/- 5.3 microM) than in nonsmokers (35.2 +/- 4.8 microM, P < 0.05). The smokers had significantly higher serum dehydroascorbic acid levels (2.4 +/- 0.5 mg/dL, P < 0.03) than the nonsmokers (1.08 +/- 0.08 mg/dL). No significant differences were observed in the levels of ascorbic acid, MDA, and GSH between the smokers and nonsmokers. CONCLUSIONS: Our results suggest that exposure to cigarette smoke increases NO synthesis, such that NO may act in a compensatory way as an inhibitor of lipid peroxidation. Smoking also activates other antioxidative mechanisms such as involving vitamin C. These protective mechanisms appear to be enough in preventing accumulation of oxidative products such as MDA and avoiding oxidative damage.     

Ciprofibrate treatment decreases non-high density lipoprotein cholesterol and triglycerides and increases high density lipoprotein cholesterol in patients with Frederickson type IV dyslipidemia phenotype

OBJECTIVE: The combination of hypertriglyceridemia and low high density lipoprotein (HDL) cholesterol is one of the most common lipid abnormalities. Thus, the aim of this study was to determine the effects of ciprofibrate on lipid profile in patients with Frederickson's type IV dyslipidemia phenotype. RESEARCH DESIGN AND METHODS: Seventy-five patients with type IV dyslipidemia were assigned at random to 1 of 2 therapeutic options: group A (control), American Heart Association (AHA) Step II diet and physical activity; and group B, AHA diet, physical activity, and ciprofibrate 100 mg daily for 8 weeks. The lipid profile of all patients was determined at baseline and after therapeutic intervention. RESULTS: Patients in group B (treated with ciprofibrate) compared with group A (control) had significantly higher reductions in total cholesterol (downward arrow 14.2% vs. downward arrow 4.8%; P < 0.02), triglycerides (downward arrow 38.0% vs. downward arrow 21.6%; P < 0.007), very low density lipoprotein cholesterol (downward arrow 38.0% vs. downward arrow 21.6%; P < 0.007), non-HDL cholesterol (downward arrow 20.5% vs. downward arrow 7.1%; P < 0.007), and total cholesterol/high density cholesterol ratio (downward arrow 25.6% vs. downward arrow 9.4%; P < 0.01). The ciprofibrate group had a significantly higher increase in HDL cholesterol levels compared with the other group (upward arrow 25.0% vs. upward arrow 9.6%, P < 0.02). CONCLUSIONS: Ciprofibrate treatment effectively reduced triglyceride-rich particles and non-HDL cholesterol, and significantly increased HDL cholesterol, proving its effectiveness in patients with low HDL cholesterol and type IV Frederickson's hyperlipidemia.     

EMG power spectra of cervical muscles in lateral flexion and comparison with sagittal and oblique plane activities

The purpose of this study was to calculate electromyographic (EMG) power spectra of the sternocleidomastoid (SCM), the splenius capitis (SPL) and the trapezius (TRP) muscles from both sides of the body in bilateral lateral flexion and compare them with the EMG spectral characteristics of the same muscles in the sagittal and oblique planes recorded from the same subjects in the same experimental session but reported elsewhere in the literature. Forty normal and healthy young adults (21 males, 19 females) volunteered for the study. The subjects were prepared and positioned appropriately to exert linearly ramping isometric exertion aided by visual feedback against a rigid and load cell instrumental device. Exertions were carried out in a random order. The maximal voluntary contraction was reached within a 5-s test period. The torque and EMG from the SCM, SPL and TRP muscles were sampled bilaterally at a rate of 1 kHz. The EMG data were subjected to fast Fourier transform analysis. During lateral flexion, the torque generated by females was significantly lower than males (P<0.01) and represented at 75% of male torque. Contrary to flexion/extension and oblique plane activities, the ipsilateral SCM was most active with highest power and up to four dominant frequencies demonstrating four distinct peaks. The bandwidth of this muscle progressively increased with the grade of contraction up to 400 Hz, similar to flexion/extension with median frequency (MF) spread between 21 and 109 Hz for males and 78 and 99 Hz for females. The ipsilateral SPL was the second most active muscle, which maintained a narrow bandwidth (200 Hz) and one dominant frequency, rising in power with increasing grade of contraction. Flexion and extension caused symmetrical activity bilaterally. The results of MANOVA revealed a significant main effect of gender, activity direction, grade of contraction and individual muscles (P<0.001). There was a significant interaction between muscle and activity direction (P<0.001) implying significantly different MF and mean power frequency if the direction of exertion was changed. Male and female subjects responded to direction differently (P<0.001). Electronic Publication     

Work-Related Musculoskeletal Disorders: Design as a Prevention Strategy. A Review

Work-related musculoskeletal disorders are of serious concern to many organizations, including industry, insurance, and health care. They are also of immediate concern to the workers and their families who are adversely affected by these disorders. Work-related musculoskeletal disorders are a substantial source of economic drain to these organizations. Sources of this drain include economic losses incurred from lost or decreased productivity as well as medical treatment and indemnity costs. Therefore, it is within the best interest of these organizations to prevent work-related musculoskeletal disorders from occurring, before they manifest into serious issues of medical, social, and economic concern. The purpose of this paper is to review the concept of work-related musculoskeletal disorders and discuss the basis of their prevention as a primary means of occupational injury and illness management. The principal contributory role of ergonomics/human factors is presented as a viable means of prevention and an important contributor to the comprehensive management of these disorders.     

Listeria pneumonitis: induction of immunity after airborne infection with Listeria monocytogenes.

After implantation of approximately 10(3) Listeria monocytogenes organisms into the lungs, mice develop an acute pneumonitis with dissemination of infection to a mediastinal lymph node (MedLN), liver, and spleen. The infections in a MedLN and spleen resolve in approximately 7 days, but the lung infection persists for a few days longer. Pneumonitis is accompanied by a lymphoproliferative response in a MedLN and spleen, and immunity to Listeria is conferred adoptively with MedLN and spleen cells but not with mesenteric lymph node cells. Although the spleen appears to be the major repository of sensitized lymphocytes, splenectomized mice combat Listeria pneumonitis as effectively as normal mice. It is concluded that the induction of immunity to lung infection with L. monocytogenes is efficient and that the cause for the rather protracted pneumonitis is due to a defect in the expression of the cell-mediated immunity effector mechanism.