Mechanical strength of fracture callus in osteopenic bone at different phases of healing

OBJECTIVES: To quantify and compare peak bending force and stiffness of fractured femurs during healing of ovariectomized (OVX) and sham-operated (SHAM) rats. DESIGN: Temporal biomechanical animal study. SETTING: Rat femurs were fractured and surgically fixed by a qualified surgeon. The inherent instability of the fixation system employed produced delayed union of the fracture. All biomechanical assessments were performed with servohydraulic test machines (Instron Inc., Canton, MA, U.S.A.; and MTS Corp., Eden Prairie, MN, U.S.A.). INTERVENTION: OVX was performed sixteen weeks before femur fracture, and the effect of OVX on healing fractures was determined. MAIN OUTCOMES: Peak bending force and stiffness of the healing femurs at four, six, and eight weeks after fracture. RESULTS: Peak bending loads of the healing fractured femurs in the OVX and SHAM animals were not significantly different. Peak bending loads for the OVX animals at four and six weeks were significantly lower than the peak load at eight weeks (p < 0.05), whereas no difference was found in the peak load with respect to time for the SHAM animals. Both SHAM and OVX animals had greater bending stiffness of the healing fractured femur after eight weeks of healing than at four weeks (p < 0.05). CONCLUSIONS: OVX is known to reduce cancellous bone mass and strength, but the effect of OVX on healing of fractures in cortical bone is controversial. This study, using a delayed-union model, found no significant differences between OVX and SHAM animals in the breaking strength of healing fractures.     

Development and implementation of an appropriateness guideline for use of CT in cases of suspected intraabdominal abscess

RATIONALE AND OBJECTIVES: The purpose of this study was to develop an evidence-based guideline for use of computed tomography (CT) in the evaluation of suspected abdominal abscess. The goal of the guidelines was to decrease the absolute number of CT examinations performed for suspected abdominal abscess and to increase the rate of positive CT examinations while not missing clinically relevant abscesses. MATERIALS AND METHODS: A multidisciplinary team developed an evidence-based guideline regarding use of CT to evaluate for suspected abscess. A control group consisted of patients scanned for suspected abscess during a 6-month period. The intervention group consisted of patients scanned in the 6 months after guideline implementation. Focal fluid collections depicted on CT scans were reviewed for both patient groups to determine if these collections were abscesses. The number and proportion of abscesses in each group were then compared. RESULTS: During the control period, 263 CT examinations for suspected abscess were performed, 75 of which (28.5%; 90% confidence interval [CI], 24%, 33%) depicted focal fluid and 25 of which (9.5%; 90% CI, 7%, 12%) depicted abscess. During the intervention period, 238 CT examinations were performed, 54 of which (22.7%; 90% CI, 18%, 27%) depicted fluid and 41 of which (17.2%; 90% CI, 13%, 21%) depicted abscess. CONCLUSION: A guideline was successful at decreasing the number of CT examinations and increasing the proportion of positive CT results for abdominal abscess. As with other inpatient utilization interventions, each practice must assess the cost-benefit trade-off of guideline implementation in complex clinical situations.     

Effects of peribulbar bupivacaine as an adjunct to general anaesthesia on peri-operative outcome following retinal detachment surgery

Sixty premedicated, ASA physical status I or II patients weighing > 25 kg scheduled for elective retinal detachment repair were randomly assigned to receive either peribulbar block with 10 ml of 0.25% bupivacaine (block group) or intravenous morphine 150 microg.kg-1 (morphine group), prior to the induction of general anaesthesia (n = 30 in each group). Patients were evaluated for intra-operative oculocardiac reflex, peri-operative pain relief, recovery from anaesthesia and postoperative nausea and vomiting. Apart from significantly reducing the incidence of oculocardiac reflex (30% vs. 70%, p = 0.0019), peribulbar bupivacaine also attenuated the severity of the reflex. Postoperative pain relief was superior in the block group. More block group patients had the maximum recovery score in the immediate postoperative period (80% vs. 27%, p < 0. 0001) and they achieved complete recovery significantly faster than the morphine group (17.3 (14.7) min vs. 66.7 (29.7) min, p < 0.0001). The incidence (40% vs. 77%, p = 0.004) and severity of postoperative nausea and vomiting were significantly less in the block group. In summary, peribulbar bupivacaine, when administered together with general anaesthesia, attenuated oculocardiac reflex, provided comparable intra-operative and superior postoperative analgesia, resulted in significantly earlier and better recovery from anaesthesia, and significantly reduced the incidence and severity of postoperative nausea and vomiting.     

Combined antioxidant and COMT inhibitor treatment reverses renal abnormalities in diabetic rats

The development and progression of diabetic nephropathy is dependent on glucose homeostasis and many other contributing factors. In the present study, we examined the effect of nitecapone, an inhibitor of the dopamine-metabolizing enzyme catechol-O-methyl transferase (COMT) and a potent antioxidant, on functional and cellular determinants of renal function in rats with streptozotocin-induced diabetes. Administration of nitecapone to diabetic rats normalized urinary sodium excretion in a manner consistent with the dopamine-dependent inhibition of proximal tubule Na,K-ATPase activity. Hyperfiltration, focal glomerulosclerosis, and albuminuria were also reversed by nitecapone, but in a manner that is more readily attributed to the antioxidant potential of the agent. A pattern of elevated oxidative stress, measured as CuZn superoxide dismutase gene expression and thiobarbituric acid-reactive substance content, was noted in diabetic rats, and both parameters were normalized by nitecapone treatment. In diabetic rats, activation of glomerular protein kinase C (PKC) was confirmed by isoform-specific translocation and Ser23 phosphorylation of the PKC substrate Na,K-ATPase. PKC-dependent changes in Na,K-ATPase phosphorylation were associated with decreased glomerular Na,K-ATPase activity. Nitecapone-treated diabetic rats were protected from these intracellular modifications. The combined results suggest that the COMT-inhibitory and antioxidant properties of nitecapone provide a protective therapy against the development of diabetic nephropathy.     

Primary rhabdomyosarcoma of the larynx

Sarcomas constitute fewer than 1% of the head and neck cancers. They represent less than 1% of laryngeal cancers. Primary rhabdomyosarcoma of the larynx is an extremely rare malignancy. The available literature on this medical oddity is in the form of isolated case reports only. The purpose of this article is to add another case of primary rhabdomyosarcoma of a rare site, the larynx, of which only 36 cases have so far been reported in the world literature. The present patient, an eighteen-year-old boy is only the third case being reported from India among all reported cases of rhabdomyosarcoma of the larynx in the world literature.     

Prophylactic ondansetron in prevention of postoperative nausea and vomiting following pediatric strabismus surgery: a dose-response study

BACKGROUND: This study evaluated the antiemetic effectiveness, dose-response, and clinical usefulness of prophylactic ondansetron in the prevention of postoperative nausea and vomiting (PONV) in children undergoing strabismus repair. METHOD: The authors observed 180 children, American Society of Anesthesiologists physical status I or II, 2-12 yr of age, who were undergoing strabismus repair. After induction of anesthesia with halothane and nitrous oxide in oxygen or intravenous thiopental, children received either placebo (saline) or intravenous ondansetron in doses of 25, 50, 75, 100, and 150 /microg/kg (n = 30). The trachea was intubated and ventilation was controlled. Perioperative analgesic and fluid requirements were standardized. Episodes of nausea and vomiting were recorded for the first 24 h postoperatively. Data such as nonsurrogate (parental satisfaction scores and duration of postanesthesia care unit stay) and therapeutic (numbers needed to prevent and harm) outcome measures were collected. RESULTS: The incidences of PONV in the placebo and 25-, 50-, 75-, 100-, and 150-,microg/kg ondansetron groups were 83, 77, 47, 30, 30, and 27%, respectively. The incidence was less in the 75(P = 0.002), 100- (P = 0.002), and 150-microg/kg (P < 0.001) ondansetron groups compared with placebo. Duration of stay in the postanesthesia care unit was shorter in the 75-, 100-, and 150-microg/kg ondansetron groups (P < 0.002) compared with the placebo group. Parental assessment scores for the child's perioperative experience and the positive number needed to prevent PONV were also better and favorable in the 75-, 100-, and 150-microg/kg ondansetron groups compared with the placebo group. The incidence (P > 0.99) and severity (P = 0.63) of PONV were similar in the 75- and 150-microg/kg ondansetron groups. Surrogate, nonsurrogate, and therapeutic outcome measures revealed that 75 microg/kg ondansetron provided the same benefits as did 100 and 150 microg/kg. CONCLUSION: The routine prophylactic use of ondansetron at a dose of 75 microg/kg is as effective as 150 microg/kg in preventing PONV and improving the "true" outcome measures after strabismus repair in children.     

Favorable prognosis for patients 12 to 18 months of age with stage 4 nonamplified MYCN neuroblastoma: a Children's Cancer Group Study.

PURPOSE: The long-term survival of children between age 12 and 24 months with stage 4 neuroblastoma and nonamplified MYCN (MYCN-NA) has not been defined previously. PATIENTS AND METHODS: Survival for stage 4 MYCN-NA neuroblastoma patients enrolled onto Children's Cancer Group (CCG) protocols 321P2 (1986 to 1991) and 3891 (1991 to 1996) was analyzed. Treatment consisted of intensive alkylator-based induction chemotherapy with or without autologous bone marrow transplantation (ABMT) with or without 13 cis-retinoic acid. Survival was analyzed by age strata less than 12, 12 to 18, 18 to 24, and more than 24 months at diagnosis. Patients younger than 12 months were treated on the moderate-intensity CCG protocol 3881. RESULTS: Forty-three patients with stage 4 MYCN-NA disease enrolled onto CCG-321P2 (n = 17) or CCG-3891 (n = 26) were between 12 and 24 months of age at diagnosis. After a median follow-up of 94 months (range, 4 to 140 months), the 6-year event-free survival (EFS) for the 12- to 18-month age group was superior to that of the 18- to 24-month age group (74% +/- 8% v 31% +/- 12%; P = .008). The EFS for children older than 24 months with stage 4 MYCN-NA neuroblastoma was 23% +/- 3%, and for children younger than 12 months was 92% +/- 3%. CONCLUSION: Children diagnosed with stage 4 MYCN-NA neuroblastoma in the second year of life form a transitional group between infants and older children in terms of prognosis. Patients between 12 and 18 months of age have significantly better long-term survival than that of older children treated with intensive chemotherapy with or without ABMT. These patients may not benefit from additional intensification of therapy beyond that provided in earlier clinical trials and may even maintain this high survival rate with less intensive therapy.