Ketamine Improves the Management of Exaggerated Postoperative Pain Observed in Perioperative Fentanyl-treated Rats

Background: Although opioids are unsurpassed analgesics, experimental and clinical studies suggest that opioids activate N-methyl-d-aspartate pronociceptive systems leading to pain hypersensitivity and short-term tolerance. Because it is difficult in humans to differentiate pain from hyperalgesia during the postoperative period, the authors performed experimental studies with fentanyl using the rat incisional pain model for evaluating relations between hyperalgesia and short-term tolerance. Because N-methyl-d-aspartate receptor antagonists oppose both pain hypersensitivity and tolerance induced by opioids, the authors examined the capability of ketamine for improving exaggerated postoperative pain management.

Methods: During halothane anesthesia, a hind paw plantar incision was performed in rats receiving four fentanyl subcutaneous injections (100 [mu]g/kg per injection, every 15 min). In some groups, three subcutaneous ketamine injections (10 mg/kg per injection, every 5 h) were performed in saline- or fentanyl-treated rats. One day after surgery, the analgesic effect of morphine (2 mg/kg subcutaneous) was tested. Analgesia, mechanical hyperalgesia, tactile allodynia, and pain score were assessed for several days using the paw pressure vocalization test, the von Frey application test, and the postural disequilibrium test.

Results: Fentanyl induced analgesia but also produced exaggerated postoperative pain as indicated by the enhancement of hyperalgesia, allodynia, and weight-bearing decrease after hind paw plantar incision. Ketamine pretreatment prevented such a fentanyl-induced enhancement of postoperative pain and improved its management by morphine.     

‘Aggressive papillary’ thyroid microcarcinoma

The objective of this study is to highlight the fact that papillary thyroid microcarcinoma can be aggressive, requiring therapeutic management similar to that of other differentiated thyroid cancers. This 8-year retrospective study concerned 187 surgical patients managed in an ENT and Head and Neck surgery department for thyroid cancer. 65 patients were found to have papillary microcarcinoma. 41 microcarcinomas were considered to be aggressive because of the presence of several risk factors such as larger than 5 mm, multifocal microcarcinomas, capsular effraction, vascular embolus, tumour extension beyond the thyroid parenchyma and metastatic lymphadenopathy. All patients with aggressive papillary microcarcinoma were treated by total thyroidectomy and ¹³¹I. Ipsilateral recurrent laryngeal and lateral cervical lymph node dissections were performed in ten patients, ipsilateral cervical lymph node dissection was performed in six patients and bilateral recurrent laryngeal and lateral cervical lymph node dissections were performed in three patients. No recurrence or metastasis was observed (follow-up ranging from 6 months to 8 years). The optimal management of thyroid papillary microcarcinoma is still controversial. “Aggressive” papillary thyroid microcarcinoma is not rare and may justify aggressive treatment depending on the presence or absence of prognostic risk factors.     

Influence of data filtering on reliability of respiratory impedance and derived parameters in children

Forced oscillation impedance (Zrs) measurements are frequently corrupted by noisy data in children. Our aim was to improve the reliability of respiratory resistance (Rrs) and routine identification of its flow (V') and volume (V) dependence during tidal breathing, according to Rrs = K1 + K2 x /V'/ + K3 x V. Zrs was measured at 12 Hz, using a head generator in 23 children aged 4-13 years undergoing methacholine (Mch) challenge. Rrs, K1, K2, K3, and residual mean square error (RMSD), as well as reproducibility of the parameters, were obtained. Calculations were performed separately in inspiration and expiration on the raw data, and after eliminating values lying outside confidence intervals ranging from 99% (F3SD) to 95% (F2SD) of the mean Zrs. Filtering decreased RMSD and Rrs, F3SD improved reproducibility of Rrs in expiration compared to raw data. F2SD increased K1 and decreased the amplitude of K2 and K3 before and after Mch compared to F3SD. Rrs and K2 were significantly larger and K3 significantly more negative in expiration than in inspiration at all levels of filtering, probably because of the upper airways. F3SD appeared efficient in eliminating aberrant data, while allowing the identification of physiological variations of Rrs.     

Low-grade Sarcomas with CD34-Positive Fibroblasts and Low-Grade Myofibroblastic Sarcomas

A subset of low-grade fibrosarcomas is composed of CD34-positive spindle cells. These include dermatofibrosarcoma, its morphologic variants, and its associated fibrosarcoma, solitary fibrous tumor, hemangiopericytoma and their malignant counterparts, and some cases of myxoinflammatory fibroblastic sarcoma. Dermatofibrosarcoma and related lesions are characterized by a t(17;22)(q22;q13) rearrangement resulting in fusion of the genes COL1A (17q21-22) and PDGFB1 (22q13). Solitary fibrous tumor displays varying cellularity and fibrosis and a peripheral hemangiopericytomatous pattern; most tumors formerly called hemangiopericytoma are now subsumed into the category of solitary fibrous tumor, although a few strictly defined examples are recognized; however, these are probably not composed of pericytes. Myofibroblastic malignancies are best identified by electron microscopy, with which varying degrees of differentiation, including the presence of fibronexus junctions, can be identified. Low-grade sarcomas showing myofibroblastic differentiation include myofibrosarcomas and inflammatory myofibroblastic tumors. Myofibrosarcomas are spindle cell neoplasms that occur in children or adults in the head and neck, trunk, and extremities as infiltrative neoplasms and that display a fascicular or fasciitis-like pattern with focal nuclear atypia and variable expression of myoid antigens. These sarcomas are prone to recurrence and a small number metastasize. Inflammatory myofibroblastic tumor (synonymous with inflammatory fibrosarcoma) is a neoplasm arising predominantly in childhood, and frequently in intraabdominal locations. It has spindle cells in fascicular, fasciitis-like and sclerosing patterns, with heavy chronic inflammation including abundant plasma cells. Many IMT have clonal chromosomal abnormalities involving 2p22-24, and fusion of the ALK gene with tropomyosin 3 (TPM3-ALK) or tropomyosin 4 (TPM4-ALK) is found in a subset.     

Symptomatic isolated internal carotid artery occlusion with initial medical management: a monocentric cohort

Journal of Neurology - Symptomatic isolated carotid artery occlusions (ICAO) can lead to disability, recurrent stroke, and mortality, but natural history and best therapeutic management remain...     

High frequency of MYC gene amplification is a common feature of radiation‐induced sarcomas. Further results from EORTC STBSG TL 01/01

Irradiation is a major causative factor among the small subgroup of sarcomas with a known etiology. The prognosis of radiation‐induced sarcomas (RIS) is significantly worse than that of their spontaneous counterparts. The most frequent histological subtypes include undifferentiated pleomorphic sarcomas, angiosarcomas, and leiomyosarcomas. A high frequency of MYC amplifications in radiation‐induced angiosarcomas, but not in primary angiosarcomas, has recently been described. To investigate whether MYC amplifications are also frequent in RIS other than angiosarcomas, we analyzed the MYC amplification status of 83 RIS and 192 sporadic sarcomas by fluorescence in situ hybridization. We found significantly higher numbers of MYC amplifications in RIS than in sporadic sarcomas (P < 0.0001), especially in angiosarcomas, undifferentiated pleomorphic sarcomas, and leiomyosarcomas. Angiosarcomas were special in that MYC amplifications were particularly frequent and always high level, while other RIS showed low‐level amplifications. We conclude that MYC amplifications are a frequent feature of RIS as a group and may contribute to the biology of these tumors. © 2012 Wiley Periodicals, Inc.     

Incidence of postoperative pain after use of calcium hydroxide mixed with normal saline or 0.2% chlorhexidine digluconate as intracanal medicament in the treatment of apical periodontitis

Objective

To compare the incidence of postoperative pain after the use of calcium hydroxide powder mixed with normal saline or 0.2% chlorhexidine digluconate as intracanal medicament.

Participants

Fifty-five subjects aged 17–60 years with teeth diagnosed to have apical periodontitis.

Intervention

Two-visit conventional root canal treatment of seventy teeth. The teeth were divided by randomization (balloting) into two groups: control group and experimental group, each with thirty-five teeth treated with calcium hydroxide mixed with normal saline or with 0.2% chlorhexidine digluconate as intracanal medicament respectively. Incidence of postoperative pain was assessed using the universal pain assessment tool and whether or not analgesic was taken.

Main outcome measured

Incidence of post-operative pain.

Result

Postoperative pain occurred only at 1-day and 1-week reviews. In the control group, the overall incidence of pain was the same at both review periods (5.7%), while the experimental group showed a slight decrease in incidence between 1-day (17.2%) and 1-week (11.4%) reviews. Incidence of flare-ups was more in the experimental group (11.4%) than in the control group (5.7%). No significant statistical differences between the two groups were observed (p > 0.05).

Conclusion

The incidence of postoperative pain was lower in the normal saline treatment group, but the difference was not statistically significant.