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Dive into the research topics where Mohamed A. Hamza is active.

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Featured researches published by Mohamed A. Hamza.


Anesthesiology | 1999

Effect of the Duration of Electrical Stimulation on the Analgesic Response in Patients with Low Back Pain

Mohamed A. Hamza; El Sayed A Ghoname; Paul F. White; William F. Craig; Hesham E. Ahmed; Noor M. Gajraj; Akshay S. Vakharia; Carl Noe

BACKGROUND Electrical stimulation of peripheral nerves produces acute analgesic effects. This randomized, sham-controlled, crossover study was designed to evaluate the effect of differing durations of electrical stimulation on the analgesic response to percutaneous electrical nerve stimulation in 75 consenting patients with low back pain. METHODS All patients received electrical stimulation for four different time intervals (0, 15, 30, and 45 min) in a random sequence over the course of an 11-week study period. All active percutaneous electrical nerve stimulation treatments were administered using alternating frequencies of 15 and 30 Hz three times per week for 2 consecutive weeks. The prestudy assessments included the health status survey short form questionnaire and 10-cm visual analog scale scores for pain, physical activity, and quality of sleep, with 0 being the best and 10 being the worst. The pain scoring was repeated 5-10 min after each 60-min study session and 24 h after the last treatment session with each of the four methods. The daily oral analgesic requirements were assessed during each of the four treatment blocks. At the end of each 2-week treatment block, the questionnaire was repeated. RESULTS Electrical stimulation using percutaneously placed needles produced short-term improvements in the visual analog scale pain, physical activity, and quality of sleep scores, and a reduction in the oral analgesic requirements. The 30-min and 45-min durations of electrical stimulation produced similar hypoalgesic effects (48+/-21% and 46+/-19%, respectively) and were significantly more effective than either 15 min (21+/-17%) or 0 min (10+/-11%). The 30- and 45-min treatments were also more effective in improving physical activity and sleep scores over the course of the 2-week treatment period. In contrast to the sham treatment (0 min), the health status survey short form revealed that electrical stimulation for 15 to 45 min three times per week for 2 weeks improved patient function. CONCLUSION The recommended duration of electrical stimulation with percutaneous electrical nerve stimulation therapy is 30 min.


Anesthesia & Analgesia | 1999

The effect of stimulus frequency on the analgesic response to percutaneous electrical nerve stimulation in patients with chronic low back pain

El Sayed A Ghoname; William F. Craig; Paul F. White; Hesham E. Ahmed; Mohamed A. Hamza; Noor M. Gajraj; Akshay S. Vakharia; Carl Noe

UNLABELLED Low back pain (LBP) is one of the most common medical problems in our society. Increasingly, patients are turning to nonpharmacologic analgesic therapies such as percutaneous electrical nerve stimulation (PENS). We designed this sham-controlled study to compare the effect of three different frequencies of electrical stimulation on the analgesic response to PENS therapy. Sixty-eight consenting patients with LBP secondary to degenerative lumbar disc disease were treated with PENS therapy at 4 Hz, alternating 15 Hz and 30 Hz (15/30 Hz), and 100 Hz, as well as sham-PENS (0 Hz), according to a randomized, cross-over study design. Each treatment was administered for a period of 30 min three times per week for 2 wk. The pre- and posttreatment assessments included the health status survey short form and visual analog scales for pain, physical activity, and quality of sleep. After receiving all four treatments, patients completed a global assessment questionnaire. The sham-PENS treatments failed to produce changes in the degree of pain, physical activity, sleep quality, or daily intake of oral analgesic medications. In contrast, 4-Hz, 15/30-Hz, and 100-Hz stimulation all produced significant decreases in the severity of pain, increases in physical activity, improvements in the quality of sleep, and decreases in oral analgesic requirements (P < 0.01). Of the three frequencies, 15/30 Hz was the most effective in decreasing pain, increasing physical activity, and improving the quality of sleep (P < 0.05). In the global assessment, 40% of the patients reported that 15/30 Hz was the most desirable therapy, and it was also more effective in improving the patients sense of well-being. We conclude that the frequency of electrical stimulation is an important determinant of the analgesic response to PENS therapy. Alternating stimulation at 15-Hz and 30-Hz frequencies was more effective than either 4 Hz or 100 Hz in improving outcome measures in patients with LBP. IMPLICATIONS The frequency of electrical stimulation seems to be an important determinant of the analgesic efficacy of percutaneous electrical nerve stimulation. Mixed low- and high-frequency stimulation was more effective than either low or high frequencies alone in the treatment of patients with low back pain.


Headache | 2000

Use of percutaneous electrical nerve stimulation (PENS) in the short-term management of headache

Hesham E. Ahmed; Paul F. White; William F. Craig; Mohamed A. Hamza; E.A. Ghoname; Noor M. Gajraj

Objective.–To evaluate the short‐term effects of percutaneous electrical nerve stimulation (PENS) in the management of three types of chronic headache.


Anesthesia & Analgesia | 2005

Optimal Timing of Acustimulation for Antiemetic Prophylaxis as an Adjunct to Ondansetron in Patients Undergoing Plastic Surgery

Paul F. White; Mohamed A. Hamza; Alejandro Recart; Jayne E. Coleman; Amy R. Macaluso; Lyndsey Cox; Omar Jaffer; Dajun Song; Rod J. Rohrich

We designed this study to evaluate the antiemetic efficacy of transcutaneous electrical acupoint stimulation in combination with ondansetron when applied before, after, or both before and after plastic surgery. A randomized, double-blind, sham-controlled study design was used to compare three prophylactic acustimulation treatment schedules: preoperative—an active device was applied for 30 min before and a sham device for 72 h after surgery; postoperative—a sham device was applied for 30 min before and an active device for 72 h after surgery; and perioperative—an active device was applied for 30 min before and 72 h after surgery (n = 35 per group). All patients received a standardized general anesthetic, and ondansetron 4 mg IV was administered at the end of surgery. The incidence of vomiting/retching and the need for rescue antiemetics were determined at specific time intervals for up to 72 h after surgery. Nausea scores were recorded with an 11-point verbal rating scale. Other outcome variables assessed included discharge times (for outpatients), resumption of normal activities of daily living, complete antiemetic response rate, and patient satisfaction with antiemetic therapy and quality of recovery. Perioperative use of the ReliefBand® significantly increased complete responses (68%) compared with use of the device before surgery only (43%). Median postoperative nausea scores were significantly reduced in the peri- and postoperative (versus preoperative) treatment groups. Finally, patient satisfaction with the quality of recovery (83 ± 16 and 85 ± 13 vs 72 ± 18) and antiemetic management (96 ± 9 and 94 ± 10 vs 86 ± 13) on an arbitrary scale from 0 = worst to 100 = best was significantly higher in the groups receiving peri- or postoperative (versus preoperative) acustimulation therapy. For patients discharged on the day of surgery, the time to home readiness was significantly reduced (114 ± 41 min versus 164 ± 50 min; P < 0.05) when acustimulation was administered perioperatively (versus preoperatively). In conclusion, acustimulation with the ReliefBand® was most effective in reducing postoperative nausea and vomiting and improving patients’ satisfaction with their antiemetic therapy when it was administered after surgery.


Anesthesia & Analgesia | 1998

Percutaneous electrical nerve stimulation: an alternative to antiviral drugs for acute herpes zoster.

Hesham E. Ahmed; William F. Craig; Paul F. White; E.A. Ghoname; Mohamed A. Hamza; Noor M. Gajraj; Stephen M. Taylor

A ntiviral drugs decrease the pain and enhance the resolution of acute herpes zoster lesions in immunocompetent patients (l-6). However, the effect of antiviral therapy on postherpetic neuralgia (PHN) remains controversial. Whereas some studies reported a lower incidence of prolonged pain with antiviral therapy (4), others found no benefit with respect to prolonged pain (5). In an attempt to improve patient comfort and long-term outcome with respect to PHN, combinations of different drugs have also been evaluated (5-7). Anecdotal reports have suggested that electroacupuncture may be helpful in the management of herpes-related pain (8,9). Clinical experience with a novel form of electroanalgesia known as percutaneous electrical nerve stimulation (PENS) in the treatment of patients with acute herpes zoster suggested that it is effective in decreasing herpes-related pain and is associated with rapid resolution of the cutaneous lesions (Craig WF, Taylor SM, Fort Worth Center for Pain Management, personal communication, 1997). Therefore, we designed this clinical study to compare PENS therapy with a standard antiviral regimen with respect to the severity of the associated pain, impact on the patient’s physical activity and quality of sleep, resolution of the herpes lesions, and incidence and severity of PHN.


Anesthesiology | 2004

Comparison of a Lower-lipid Propofol Emulsion with the Standard Emulsion for Sedation during Monitored Anesthesia Care

Dajun Song; Mohamed A. Hamza; Paul F. White; Stephanie Byerly; Stephanie B. Jones; Amy D. Macaluso

Background: The currently used emulsion formulations of 1% propofol contain 10% soybean oil. However, a new emulsion of 1% propofol (Ampofol) containing 50% less lipid has recently become available for clinical investigation. This study was designed to compare the pharmacodynamic properties of Ampofol with those of a standard formulation (Diprivan) when administered for intraoperative sedation. Methods: Sixty healthy outpatients undergoing minor operations with local anesthesia were randomly assigned to receive either Ampofol (n = 31) or Diprivan (n = 29) for intravenous sedation. The sedation was initiated with an intravenous loading dose of propofol, 0.75 mg/kg, followed by an initial infusion rate of 50 μg · kg−1 ·min−1 to achieve an Observer’s Assessment of Alertness/Sedation score of 3. The targeted level of sedation was maintained with a variable-rate propofol infusion during the operation. The onset times to achieving a sedation score of 3, the severity of pain on injection of the loading dose, intraoperative hemodynamic variables, and electroencephalographic Bispectral Index values were recorded. In addition, recovery times, postoperative pain and nausea, and patient satisfaction with the sedative medication were assessed. Results: There were no significant differences between Ampofol and Diprivan with respect to onset times, dosage requirements, Bispectral Index values, hemodynamic variables, recovery times, or patient satisfaction scores. The incidence of moderate pain on injection was higher in the Ampofol group (26%vs. 7% with Diprivan; P < 0.05). Conclusions: Ampofol was equipotent to Diprivan with respect to its sedative properties during monitored anesthesia care. Although both groups received pretreatment with intravenous lidocaine, Ampofol was associated with more pain on injection.


Anesthesia & Analgesia | 2006

The use of oral granisetron versus intravenous ondansetron for antiemetic prophylaxis in patients undergoing laparoscopic surgery: the effect on emetic symptoms and quality of recovery.

Paul F. White; Jun Tang; Mohamed A. Hamza; Babatunde Ogunnaike; Monica Lo; Ronald H. Wender; Robert Naruse; Alexander Sloninsky; Robert Kariger; Scott A. Cunneen; Ted Khalili

Based on comparative studies in patients receiving emetogenic chemotherapy, it has been suggested that granisetron would be more effective than ondansetron for the prevention of postdischarge nausea and vomiting (PDNV). However, there have been no direct comparisons of these two popular 5-HT3 antagonists with respect to PDNV and quality of recovery. We designed this randomized, double-blind study to compare the antiemetic efficacy of oral granisetron (1 mg) to a standard IV dose of ondansetron (4 mg) when administered for antiemetic prophylaxis as part of a multimodal regimen in a laparoscopic surgical population. A total of 220 patients undergoing laparoscopic surgery with a standardized general anesthetic technique were enrolled in this prospective study at two major medical centers. Patients were randomly assigned to one of two prophylactic treatment groups: the control (ondansetron) group received an oral placebo 1 h before surgery and ondansetron, 4 mg IV, at the end of the surgery, and the granisetron group received granisetron, 1 mg per os, 1 h before surgery, and normal saline, 2 mL IV, at the end of the surgery. The early recovery profiles, requirement for rescue antiemetics, incidence of PDNV, and the side effects were recorded over the 48 h study period. In addition, nausea scores were assessed using an 11-point verbal rating scale at specific intervals in the postoperative period. The quality of recovery and patient satisfaction scores were recorded at 48 h after surgery. The demographic characteristics were similar in the two prophylaxis treatment groups, as well as the recovery times to patient orientation, oral intake, and hospital discharge. The incidences of PDNV, requirements for rescue antiemetics, and quality of recovery did not differ between the two study groups. The antiemetic drug acquisition costs to achieve comparable patient satisfaction with ondansetron and granisetron were US


Frontiers in Cell and Developmental Biology | 2016

Redox Regulation of Heart Regeneration: An Evolutionary Tradeoff.

Waleed M. Elhelaly; Nicholas T. Lam; Mohamed A. Hamza; Shuda Xia; Hesham A. Sadek

25.65 and


JAMA | 1999

Percutaneous electrical nerve stimulation for low back pain: a randomized crossover study.

El Sayed A Ghoname; William F. Craig; Paul F. White; Hesham E. Ahmed; Mohamed A. Hamza; Brent N. Henderson; Noor M. Gajraj; Philip J. Huber; Robert J. Gatchel

47.05, respectively. Therefore, ondansetron (4 mg IV) was more cost-effective than granisetron (1 mg per os) for routine antiemetic prophylaxis as part of a multimodal regimen in patients undergoing either outpatient or inpatient laparoscopic surgery.


Diabetes Care | 2000

Percutaneous electrical nerve stimulation: a novel analgesic therapy for diabetic neuropathic pain.

Mohamed A. Hamza; Paul F. White; William F. Craig; El Sayed A Ghoname; Hesham E. Ahmed; Timothy J. Proctor; Carl Noe; Akshay S. Vakharia; Noor M. Gajraj

Heart failure is a costly and deadly disease, affecting over 23 million patients worldwide, half of which die within 5 years of diagnosis. The pathophysiological basis of heart failure is the inability of the adult heart to regenerate lost or damaged myocardium. Although limited myocyte turnover does occur in the adult heart, it is insufficient for restoration of contractile function (Nadal-Ginard, 2001; Laflamme et al., 2002; Quaini et al., 2002; Hsieh et al., 2007; Bergmann et al., 2009, 2012). In contrast to lower vertebrates (Poss et al., 2002; Poss, 2007; Jopling et al., 2010; Kikuchi et al., 2010; Chablais et al., 2011; González-Rosa et al., 2011; Heallen et al., 2011), adult mammalian heart cardiomyogenesis following injury is very limited (Nadal-Ginard, 2001; Laflamme et al., 2002; Quaini et al., 2002; Bergmann et al., 2009, 2012) and is insufficient to restore normal cardiac function. Studies in the late 90s elegantly mapped the DNA synthesis and cell cycle dynamics of the mammalian heart during development and following birth (Soonpaa et al., 1996; Soonpaa and Field, 1997, 1998), where they showed that DNA synthesis drops significantly around birth with low-level DNA synthesis few days after birth. Around P5 to P7, cardiomyocytes undergo a final round of DNA synthesis without cytokinesis, and the majority become binucleated and exit the cell cycle permanently. Therefore, due to the similarities between the immature mammalian heart and lower vertebrates (Poss, 2007; Walsh et al., 2010), it became important to determine whether they have similar regenerative abilities. Recently, we demonstrated that removal of up to 15% of the apex of the left ventricle of postnatal day 1 (P1) mice results in complete regeneration within 3 weeks without any measurable fibrosis and cardiac dysfunction (Porrello et al., 2011). This response is characterized by robust cardiomyocyte proliferation with gradual restoration of normal cardiac morphology. In addition to the histological evidence of proliferating myocytes, genetic fate-mapping studies confirmed that the majority of newly formed cardiomyocytes are derived from proliferation of preexisting cardiomyocytes (Porrello et al., 2011). More recently, we established an ischemic injury model where the left anterior descending coronary artery was ligated in P1 neonates (Porrello et al., 2013). The injury response was similar to the resection model, with robust cardiomyocyte proliferation throughout the myocardium, as well as restoration of normal morphology by 21 days. However, this regenerative capacity is lost by P7, after which injury results in the typical cardiomyocyte hypertrophy and scar-formation characteristic of the adult mammalian heart. Not surprisingly, the loss of this regenerative capacity coincides with binucleation and cell cycle exit of cardiomyocytes (Soonpaa et al., 1996; Walsh et al., 2010). An important approach toward a deeper understanding the loss of cardiac regenerative capacity in mammals is to first consider why, and not only how, this happens. Regeneration of the early postnatal heart following resection or ischemic infarction involves replacement of lost myocardium and vasculature with restoration of normal myocardial thickness and architecture, with long-term normalization of systolic function. Why would the heart permanently forego such a remarkable regenerative program shortly after birth? The answer may lie in within the fundamental principal of evolutionary tradeoff.

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Paul F. White

University of Texas Southwestern Medical Center

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Hesham E. Ahmed

University of Texas Southwestern Medical Center

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William F. Craig

University of Texas Southwestern Medical Center

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Noor M. Gajraj

University of Texas Southwestern Medical Center

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E.A. Ghoname

University of Texas Southwestern Medical Center

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El Sayed A Ghoname

University of Texas Southwestern Medical Center

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Carl Noe

University of Texas Southwestern Medical Center

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Philip J. Huber

University of Texas Southwestern Medical Center

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Robert J. Gatchel

University of Texas at Arlington

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