Biomedical subjects

M Ames

Publications and source records attributed to M Ames.

18 recordsLinked to original sources

PubMed2001

Activation of plasma coagulation by retransfusion of unwashed drainage blood after hip joint arthroplasty: a prospective study.

Twelve patients undergoing cementless hip joint arthroplasty were retransfused with unwashed drainage blood collected postoperatively. Global coagulation parameters, coagulation factors (factor V:C, factor VIII:C, activated factor XII, and factor XIII) and markers of thrombin generation (F1+2 Fibrin split products, thrombin-antithrombin complexes), fibrin generation (fibrinogen and fibrin degradation products), and fibrinolysis (D-dimers, thrombin degradation products, plasminogen) were determined. High levels of factor XIIa, thrombin and fibrin generation markers, and markers of fibrinolysis were present in the shed blood. After retransfusion (mean, 433 mL), increased levels of these markers together with decreased values for factor XIII and plasminogen were indicative of renewed clot formation and fibrinolysis in the circulation. These changes were highly significant compared with preretransfusion values. The unwashed drainage blood contained high levels of procoagulation material and induced an activation of the plasma coagulation pathway with renewed clot formation and fibrinolysis in the patients.

Aged↗

PubMed2000

Superoxide regulation of endothelin-converting enzyme.

Reactive oxygen species (ROS) act as signaling molecules in the cardiovascular system, regulating cellular proliferation and migration. However, an excess of ROS can damage cells and alter endothelial cell function. We hypothesized that endogenous mechanisms protect the vasculature from excess levels of ROS. We now show that superoxide can inhibit endothelin-converting enzyme activity (ECE) and decrease endothelin-1 synthesis. Superoxide inhibits ECE but hydrogen peroxide and nitric oxide do not. Superoxide inhibits ECE by ejecting zinc from the enzyme, and the addition of exogenous zinc restores enzymatic activity. Superoxide may inhibit other zinc metalloproteinases by a similar mechanism and may thus play an important role in regulating the biology of blood vessels.

Animals↗

PubMed1999

[Iatrogenious arteriovenous fistula: rare complication after knee arthroscopy].

Vascular damage due to arthroscopy is a rare complication. Postoperative occurrence of an arteriovenous fistula after using an electric hook for arthroscopic partial medial meniscectomy is described. Due to uncharacteristic symptoms of the arteriovenous fistula as a vascular complication after arthroscopy, the correct diagnosis may take a long time. In order to avoid damage to the popliteal vessels, the removal of the posterior horn of the medial meniscus should be performed under best visibility conditions with mild flexion and only mild external rotation of the calf. Considering the severe consequences, popliteal vascular damage is worth mentioning during preoperative information, even if it is an extremely rare complication.

Adult↗

PubMed1999

A multicenter, double-blind, randomized comparison of oral ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with highly emetogenic chemotherapy. S3AA3012 Study Group.

The objectives of this study were to compare the efficacy and safety of orally administered ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with high-dose cisplatin-based chemotherapy (cisplatin > or = 50 mg/m2). This was a randomized, parallel-group, double-blind study conducted in North America. It was planned that all patients would receive one of the following orally administered ondansetron treatments 30 min before starting cisplatin dosing (administered over < or = 3 h): 8 mg b.i.d. with 8 h between doses (124 patients), 24 mg q.d. (116 patients), and 32 mg q.d. (117 patients). Use of prophylactic corticosteroids was not permitted. During the 24-h study period, the highest complete response rate (no emesis, rescue antiemetic therapy, or withdrawal) occurred in patients who received ondansetron 24 mg q.d.: 76/115 or 66%, as against 68/124 (55%) after ondansetron 8 mg b.i.d. and 64/117 (55%) after ondansetron 32 mg q.d. Complete control of nausea (no nausea, no rescue, no withdrawal) occurred in more patients in the ondansetron 24 mg q.d. group (64/114, 56%) than in the ondansetron 8 mg b.i.d. group (43/121, 36%) or in the ondansetron 32 mg group (55/117, 50%). These results demonstrate that following highly emetogenic cisplatin-based chemotherapy (> or =2 50 mg/m2), oral ondansetron 24 mg q.d. is more effective than 8 mg b.i.d. for overall control of nausea, and at least as effective if not more effective in the control of acute vomiting than 8 mg b.i.d. or 32 mg q.d. Ondansetron 24 mg q.d. was well tolerated, and no new or unexpected adverse events were identified.

Administration, Oral↗

PubMed1999

Intravenous ondansetron for the control of opioid-induced nausea and vomiting. International S3AA3013 Study Group.

This randomized, double-masked, placebo-controlled, multicenter trial was conducted in 9 countries to assess the safety and efficacy of 2 doses of intravenous ondansetron (8 and 16 mg) for the control of opioid-induced nausea and vomiting. A total of 2574 nonsurgical patients who presented with pain requiring treatment with an opioid analgesic agent participated in this trial. The most common presenting painful condition was back or neck pain, reported by approximately one third of patients. A total of 520 patients (317 females, 203 males) developed nausea or vomiting after opioid administration and were randomly assigned to receive a single dose of 1 of 3 study treatments: placebo (n = 94), ondansetron 8 mg (n = 215), or ondansetron 16 mg (n = 211). Ondansetron 8 and 16 mg led to complete control of emesis in 134 of 215 patients (62.3%) and 145 of 211 patients (68.7%), respectively. Results with both doses were significantly better than those seen with placebo (43 of 94 patients [45.7%]). Complete control of nausea was achieved in 6.8% of placebo patients, 14.8% of ondansetron 8-mg-treated patients, and 19.4% of ondansetron 16-mg treated patients; only ondansetron 16 mg was significantly better than placebo (P = 0.007). Significantly more patients who received ondansetron 8 mg than patients who received placebo were satisfied/very satisfied with their antiemetic treatment, as assessed by 4 patient-satisfaction questions. Significantly more patients who received ondansetron 16 mg compared with placebo were satisfied/very satisfied on 2 of 4 satisfaction questions. In conclusion, based on the observed incidence of opioid-induced nausea and vomiting in this study, it may be more appropriate to treat symptoms on occurrence rather than administering antiemetic agents prophylactically. The results of this study demonstrate that intravenous ondansetron in doses of 8 or 16 mg is an effective antiemetic agent for the control of opioid-induced nausea and vomiting in nonsurgical patients requiring opioid analgesia for pain.

Adult↗

PubMed1998

A ganglion of the superior tibiofibular joint as a mucoid-cystic degeneration of unusual localization. A case report and review of the literature.

This paper presents the case of a 51-year-old man with a ganglion originating from the superior tibiofibular joint. In the context of the present literature, different theories of the pathogenesis, clinical symptoms, various kinds of imaging methods in regard of the differential diagnosis and the broad spectrum of operative and non-operative treatment are discussed.

Fibula↗

PubMed1998

A Comparison of Oral Ondansetron and Intravenous Granisetron for the Prevention of Nausea and Emesis Associated with Cisplatin-Based Chemotherapy.

PURPOSE: To compare the efficacy and safety of oral ondansetron with i.v. granisetron each given as a single dose prior to administration of highly emetogenic cisplatin chemotherapy. PATIENTS AND METHODS: Chemotherapy-naive patients with histologically confirmed malignancies were randomized to receive a single 24 mg ondansetron hydrochloride tablet plus a 50 ml i.v. infusion of normal saline, or a single 10 µg/kg (50 ml) i.v. infusion of granisetron plus a placebo tablet in this multicenter, double-blind, parallel-group trial. Study drug was administered 30 min prior to a single i.v. infusion of cisplatin (50-75 mg/m²), given over a period of </= 3 h. Concurrent administration of corticosteroids was not allowed. Efficacy measurements included the number of emetic episodes, need for rescue medication, and patient assessments of nausea and appetite. Complete response (CR) was defined as no emetic episodes, rescue, or withdrawal; major response was defined as one or two episodes. Safety was evaluated by monitoring adverse events and changes in laboratory parameters. RESULTS: A total of 371 patients entered the study and received study drug, of whom 184 received ondansetron and 187 received granisetron. For all parameters tested, a single 24 mg oral ondansetron tablet was at least as effective as i.v. granisetron. CR was achieved in 58% of ondansetron-treated patients and 51% of granisetron-treated patients (95% confidence interval on the difference: -4% to 17%). Subjective assessments revealed no difference with regard to complete control of nausea, appetite, or satisfaction with antiemetic therapy. Both drugs were well tolerated; the most common adverse event was headache. CONCLUSION: A single 24 mg oral dose of ondansetron is at least as safe and effective as a single i.v. infusion of 10 µg/kg of granisetron in preventing nausea and vomiting induced by highly emetogenic cisplatin chemotherapy.

Journal Article↗

PubMed1992

The role of selection bias in comparing cesarean birth rates between physician and midwifery management.

OBJECTIVE: The midwifery service at our hospital has been observed to have a 2% cesarean birth rate consistently over a 10-year period. There are substantial differences in labor management style between the midwives and physicians. We sought to test the hypothesis that the low cesarean birth rate on the midwifery service was the result of patient selection bias. METHODS: A randomized blinded clinical trial was conducted in which 492 low-risk patients were assigned to either physician or midwifery management. The provider responsible for labor management was unable to determine group assignment. Patients in the midwifery group were managed by previously established protocols, and outcome was attributed to the midwives even if the patients subsequently required transfer to physician management. Route of delivery was the primary outcome measurement. Continuous variables were analyzed using Student t test and discrete variables using chi 2. RESULTS: There were no demographic differences between the groups, and the admission pelvic examinations were the same. The patients assigned to the midwifery group had a 2.1% cesarean birth rate, whereas those assigned to physician management had a 0.4% rate. The higher rate of operative vaginal deliveries in the physician group was statistically significant. There were no differences in neonatal outcomes. The physician-managed group had significantly more episiotomies and third- and fourth-degree extensions. CONCLUSIONS: The 2% cesarean birth rate observed on the midwifery service appeared to be the result of patient selection bias. A low cesarean birth rate can be achieved by either physician or midwifery management in a selected low-risk population.

Adult↗

PubMed1991

[Clinical evaluation of a test strip for measuring creatinine in capillary blood of children].

Basing on an enzymatic method for determining creatinine, the new reagent strip "Reflotron Creatinin" of the Reflotron system recently was presented. In this study, it will be compared with another enzymatic test (Creatinin-PAP) and with a Jaffe-based assay (Creatinin-Jaffe for Hitachi 737). The quality control (within-days and within-series) yielded a sufficient accuracy and precision (CV = 4%) for the charge of used test strips. The recovery of double measured values was very good (r greater than 0.94). As regards the method comparison, differences in both charges were seen. The values of the former charge lay 7% on an average below the Jaffe-values, those of the latter 28% below. The slope of the latter regression line was considerably steeper. Comparing both enzymatic tests, the regression analysis gave poor results (y = -0.33 + 1.35 x). Bilirubin had not remarkable influences, whereas an evelated hematocrit slightly depressed the values. It seems necessary to start further studies to clear up the difference in test strip charges and to check more capillary blood samples of newborn and children with a pathologic creatinine level.

Child↗

PubMed1989

Ethnicity: post-traumatic stress disorder (PTSD) differences among black, white, and Hispanic veterans who differ in degrees of exposure to combat in Vietnam.

Clinical observations and empirical evidence suggest that, among Vietnam combat veterans, Blacks are more maladjusted than Whites (e.g., Parsons, 1985; Penk et al., 1985). The prediction that minority group status is associated with poorer post-war adjustment and higher rates of PTSD was examined among Vietnam combat veterans who were seeking treatment for addiction disorders. Adjustment scores among groups comparable in combat exposure were found to be similar for both Whites and Hispanics; Blacks, however, score significantly higher on both PTSD symptoms on MMPI scales. These findings indicate that ethnicity contributes importantly to PTSD in selected instances, but that minority group status alone does not account for observed differences. Additional research is indicated in which careful attention is given to the complicating and interacting role of addiction disorders in sampling.

Adaptation, Psychological↗

PubMed1988

Ultrasound and magnetic resonance imaging of pelvic masses.

Magnetic resonance imaging (MRI) is a complementary imaging modality to ultrasound in the evaluation of pelvic masses. Indications for MRI include differentiating a uterine from an adnexal mass when the ultrasound is inconclusive, establishing the presence of blood in a "simple" appearing cyst and demonstrating fat within a mass that is sonographically suspicious of a benign cystic teratoma.

Adnexal Diseases↗

PubMed1978