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Fadia Haddad

Publications and source records attributed to Fadia Haddad.

32 records · Page 2Linked to original sources
PubMed2003

Acute molecular responses of skeletal muscle to resistance exercise in able-bodied and spinal cord-injured subjects.

Spinal cord injury (SCI) results in muscle atrophy, which contributes to a number of health problems, such as cardiovascular deconditioning, metabolic derangement, and osteoporosis. Electromyostimulation (EMS) holds the promise of ameliorating SCI-related muscle atrophy and, therefore, improving general health. To date, EMS training of long-term SCI subjects has resulted in some muscle hypertrophy but has fallen short of normalizing muscle mass. The aim of this study was to compare the molecular responses of vastus lateralis muscles from able-bodied (AB) and SCI subjects after acute bouts of EMS-induced resistance exercise to determine whether SCI muscles displayed some impairment in response. Analysis included mRNA markers known to be responsive to increased loading in rodent muscles. Muscles of AB and SCI subjects were subjected to EMS-stimulated exercise in two 30-min bouts, separated by a 48-h rest. Needle biopsy samples were obtained 24 h after the second exercise bout. In both the AB and SCI muscles, significant changes were seen in insulin-like growth factor binding proteins 4 and 5, cyclin-dependent kinase inhibitor p21, and myogenin mRNA levels. In AB subjects, the mRNA for mechano-growth factor was also increased. Before exercise, the total RNA concentration of the SCI muscles was less than that of the AB subjects but not different postexercise. The results of this study indicate that acute bouts of resistance exercise stimulate molecular responses in the skeletal muscles of both AB and SCI subjects. The responses seen in the SCI muscles indicate that the systems that regulate these molecular responses are intact, even after extended periods of muscle unloading.

Adult↗
PubMed2003

Gender differences in resistance-training-induced myofiber hypertrophy among older adults.

We tested the hypothesis that older men (n = 9, 69 +/- 2 years) would experience greater resistance-training-induced myofiber hypertrophy than older women (n = 5, 66 +/- 1 years) following knee extensor training 3 days per week at 65-80% of one-repetition maximum for 26 weeks. Vastus lateralis biopsies were analyzed for myofiber areas, myosin heavy chain isoform distribution, and levels of mRNA for insulin-like growth factor 1 (IGF-1), IGFR1, and myogenin. Gender x Training interactions (p <.05) indicate greater myofiber hypertrophy for all three primary fiber types (I, IIa, IIx) and enhanced one-repetition maximum strength gain in men compared with women (p <.05). Covarying for serum IGF-1, dehydroepiandrosterone sulfate, or each muscle mRNA did not negate these interactions. In both genders, type IIx myofiber area distribution and myosin heavy chain type IIx distribution decreased with a concomitant increase in type IIa myofiber area distribution (p <.05). In summary, gender differences in load-induced myofiber hypertrophy among older adults cannot be explained by levels of circulating IGF-1 or dehydroepiandrosterone sulfate, or by expression of the myogenic transcripts examined.

Aged↗
PubMed2002

Prophylactic ondansetron is effective in the treatment of nausea and vomiting but not on pruritus after cesarean delivery with intrathecal sufentanil-morphine.

STUDY OBJECTIVES: To assess the safety and efficacy of ondansetron for prevention of pruritus, nausea and vomiting after cesarean delivery with intrathecal sufentanil-morphine. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Referral center, institutional practice. PATIENTS: 100 nonbreastfeeding women undergoing elective cesarean delivery with sufentanil-morphine-bupivacaine anesthesia. INTERVENTIONS: After the umbilical cord was clamped, patients in Group 1 received ondansetron 8 mg intravenously (IV) and patients in Group 2 received placebo. MEASUREMENTS: Frequency and severity of postoperative (24-hour) pruritus, nausea and vomiting, surgical pain, and side effects related to ondansetron were recorded. MAIN RESULTS: In the ondansetron group, 38 patients had pruritus (16 mild and 22 severe) and 9 patients had nausea and vomiting (5 mild and 4 severe). In the placebo group, 41 patients had pruritus (21 mild and 20 severe) and 29 patients had nausea and vomiting (9 mild and 15 severe). The frequency and severity of the nausea and vomiting episodes were significantly reduced in the ondansetron group. Pain scores were comparable between groups. No side effects related to ondansetron were reported. CONCLUSIONS: Prophylactic IV ondansetron 8 mg is safe and effective in reducing the frequency and the severity of nausea and vomiting, but not pruritus, following cesarean delivery with intrathecal sufentanil-morphine.

Adult↗
PubMed2002

Postoperative oral amiodarone as prophylaxis against atrial fibrillation after coronary artery surgery.

OBJECTIVE: To assess the prophylactic effect of postoperative oral amiodarone on the incidence and severity of atrial fibrillation (AF) after coronary artery surgery. DESIGN: Prospective, randomized, blinded, controlled study. SETTING: University hospital. PARTICIPANTS: Patients who had coronary artery surgery (n = 200). INTERVENTIONS: Patients in group 1 (n = 100) received oral amiodarone, 15 mg/kg, 4 hours after arrival in the intensive care unit, followed by 7 mg/kg/d until hospital discharge. Patients in group 2 (n = 100) received placebo. MEASUREMENTS AND MAIN RESULTS: Incidence, duration, and recurrence of new episodes of AF and maximal ventricular rate response were recorded from day 0 until hospital discharge. Side effects related to amiodarone and complications induced by new-onset AF were noted. The incidence of new-onset AF (12% v 25%) and maximal ventricular rate response (120 +/- 21 beats/min v 135 +/- 24 beats/min) were significantly lower in the amiodarone group. There were no side effects related to the administration of amiodarone. The incidence of complications induced by AF was comparable between the 2 groups. CONCLUSION: Postoperative prophylactic oral amiodarone after coronary artery surgery is safe and effective in reducing the incidence of new-onset AF and maximal ventricular rate response.

Administration, Oral↗
PubMed2002

Skeletal muscle plasticity: cellular and molecular responses to altered physical activity paradigms.

The goal of this article is to examine our current understanding of the chain of events known to be involved in the adaptive process whereby specific genes and their protein products undergo altered expression; specifically, skeletal muscle adaptation in response to altered loading states will be discussed, with a special focus on the regulation of the contractile protein, myosin heavy chain gene expression. This protein, which is both an important structural and regulatory protein comprising the contractile apparatus, can be expressed as different isoforms, thereby having an impact on the functional diversity of the muscle. Because the regulation of the myosin gene family is under the control of a complex set of processes including, but not limited to, activity, hormonal, and metabolic factors, this protein will serve as a cellular "marker" for studies of muscle plasticity in response to various mechanical perturbations in which the quantity and type of myosin isoform, along with other important cellular proteins, are altered in expression.

Adaptation, Physiological↗
PubMed2002

Cellular and molecular responses to increased skeletal muscle loading after irradiation.

Irradiation of rat skeletal muscles before increased loading has been shown to prevent compensatory hypertrophy for periods of up to 4 wk, possibly by preventing satellite cells from proliferating and providing new myonuclei. Recent work suggested that stem cell populations exist that might allow irradiated muscles to eventually hypertrophy over time. We report that irradiation essentially prevented hypertrophy in rat muscles subjected to 3 mo of functional overload (OL-Ir). The time course and magnitude of changes in cellular and molecular markers of anabolic and myogenic responses were similar in the OL-Ir and the contralateral nonirradiated, overloaded (OL) muscles for the first 3-7 days. These markers then returned to control levels in OL-Ir muscles while remaining elevated in OL muscles. The number of myonuclei and amount of DNA were increased markedly in OL but not OL-Ir muscles. Thus it appears that stem cells were not added to the irradiated muscles in this time period. These data are consistent with the theory that the addition of new myonuclei may be required for compensatory hypertrophy in the rat.

Adaptation, Physiological↗
PubMed2002

Transcriptional regulation of the type I myosin heavy chain promoter in inactive rat soleus.

Chronic muscle inactivity with spinal cord isolation (SI) decreases expression of slow type I myosin heavy chain (MHC) while increasing expression of the faster MHC isoforms, primarily IIx. The purpose of this study was to determine whether type I MHC downregulation in the soleus muscle of SI rats is regulated transcriptionally and to identify cis-acting elements or regions of the rat type I MHC gene promoter involved in this response. One week of SI significantly decreased in vivo activity of the -3500-, -408-, -299-, -215-, and -171-bp type I MHC promoters. The activity of all tested deletions of the type I MHC promoter, relative to the human skeletal alpha-actin promoter, were significantly reduced in the SI soleus, except activity of the -171-bp promoter, which increased. Mutation of the betae3 element (-214/-190 bp) in the -215- and -408-bp promoters and deletion of this element (-171-bp promoter) attenuated type I downregulation with SI. Gel mobility shift assays demonstrated a decrease in transcription enhancer factor-1 binding to the betae3 element with SI, despite an increase in total binding to this region. These results demonstrate that type I MHC downregulation with SI is transcriptionally regulated and suggest that interactions between transcription enhancer factor-1 and the betae3 element are likely involved in this response.

Animals↗
PubMed2002

Functional overload increases beta-MHC promoter activity in rodent fast muscle via the proximal MCAT (betae3) site.

Functional overload (OL) of the rat plantaris muscle by the removal of synergistic muscles induces a shift in the myosin heavy chain (MHC) isoform expression profile from the fast isoforms toward the slow type I, or, beta-MHC isoform. Different length rat beta-MHC promoters were linked to a firefly luciferase reporter gene and injected in control and OL plantaris muscles. Reporter activities of -3,500, -914, -408, and -215 bp promoters increased in response to 1 wk of OL. The smallest -171 bp promoter was not responsive to OL. Mutation analyses of putative regulatory elements within the -171 and -408 bp region were performed. The -408 bp promoters containing mutations of the betae1, distal muscle CAT (MCAT; betae2), CACC, or A/T-rich (GATA), were still responsive to OL. Only the proximal MCAT (betae3) mutation abolished the OL response. Gel mobility shift assays revealed a significantly higher level of complex formation of the betae3 probe with nuclear protein from OL plantaris compared with control plantaris. These results suggest that the betae3 site functions as a putative OL-responsive element in the rat beta-MHC gene promoter.

Animals↗
PubMed2002

Selected contribution: acute cellular and molecular responses to resistance exercise.

Training protocols apply sequential bouts of resistance exercise (RE) to induce the cellular and molecular responses necessary to produce compensatory hypertrophy. This study was designed to 1) define the time course of selected cellular and molecular responses to a single bout of RE and 2) examine the effects of interbout rest intervals on the summation of these responses. Rat muscles were exposed to RE via stimulation of the sciatic nerve in vivo. Stimulated and control muscles were obtained at various time points post-RE and analyzed via Western blot and RT-PCR. A single bout of RE increased intracellular signaling (i.e., phosphorylations) and expression of mRNAs for insulin-like growth factor-I system components and myogenic markers (e.g., cyclin D1, myogenin). A rest interval of 48 h between RE bouts resulted in much greater summation of myogenic responses than 24- or 8-h rest intervals. This experimental approach should be useful for studying the regulatory mechanisms that control the hypertrophy response. These methods could also be used to compare and contrast different exercise parameters (e.g., concentric vs. eccentric, etc.).

Animals↗
PubMedDate not supplied

[Thoracic epidural and intrathecal analgesia have similar effects on pain relief and respiratory function after thoracic surgery].

PURPOSE: To compare in a prospective randomized trial the effects of thoracic epidural infusions of fentanyl (F) and bupivacaine (B) to intrathecal morphine (M) and sufentanil (S) on analgesia and respiratory function following thoracotomy. PATIENTS AND METHODS: 55 patients undergoing an elective postero-lateral thoracotomy were randomly assigned to one of two groups: Group I (n = 27): received intrathecal S (5 microg) and M (0.5 mg) one hour before surgery. Group II (n = 28) received, after induction of anesthesia, an initial dose of 10 to 20 mL of a solution of B 0.25% and F 2 microg.mL(-1) via an epidural thoracic catheter previously inserted between T5 and T8. The same solution was infused during surgery. After surgery, patients received a continuous infusion of B 0.1% and F 2 microg.mL(-1) with a bolus every 15 min if needed. Heart rate (HR), mean arterial pressure (MAP), SpO(2), PaCO(2), respiratory rate (RR), forced expiratory volume in one second, peak expiratory flow rate and forced vital capacity were recorded at different times from the day before surgery till T48 = 48 hr after surgery. Subjective pain was assessed using a 10 cm visual analogue scale (VAS) scoring at rest and during cough. RESULTS: No significant difference was noted between both groups concerning VAS, HR, MAP, SpO(2), PaCO(2) and RR. Variations of the respiratory function tests were identical in both groups. CONCLUSION: This study shows that intrathecal M and S offer analgesia comparable to thoracic epidural infusion of B and F.

Analgesia↗