A pilot study on the effects of direct contact of two different surgical burs on the cadaveric lingual nerve

The lingual guttering technique for third molar surgery carries the risk of injury to the lingual nerve if the surgical bur comes into direct contact with it. This study investigated the extent of nerve injury caused by two different burs, a tungsten carbide bur and the Dentium implant bur; the latter is designed to be soft tissue friendly. This study also examined whether ultrasound and magnetic resonance imaging are able to detect any injury inflicted. This cadaveric research involved subjecting 12 lingual nerves to the drilling effect of two different burs at two different speeds. The amount of damage caused was measured using different imaging modalities to assess their ability to detect the injury inflicted. At high speed, the Dentium bur caused a deeper and wider laceration than the carbide bur. At low speed, the laceration depths and widths caused by the two burs did not differ significantly. Ultrasound scanning was able to detect the nerve laceration at damaged sites observed using optical coherence tomography. Thus, a carbide bur (at low speed) would be preferable for lingual bone guttering, as it causes less laceration to the lingual nerve. In the event of a suspected injury, ultrasound scanning would provide an objective evaluation of the amount of nerve damage in vivo.

Association of PIK3CA gene mutations with head and neck squamous cell carcinomas

The Phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA) is an important regulator of cell signaling pathways in human cancers. Mutations in PIK3CA were found to be associated with more aggressive clinical outcome and aberrant activation of cellular mechanisms in cancers. Hence the present study aimed to understand the mutations in the PIK3CA gene in head and neck squamous cell carcinomas (HNSCC). After the approval of the Institutional Ethics Committee we recruited 129 HNSCC patients and 150 healthy controls for screening of mutations in the helical (exon9) and kinase domain (exon 20) of the PIK3CA gene using PCR, SSCP and Sanger Sequencing. We found about 60.46% of HNSCC patients and 26% of controls with the following mutations 1634A>C (E545A) and 3075C>T (T1025T) in the helical and kinase domains of PIK3CA. Both these mutations 1634A>C and 3075C>T were more prominent in oral cancers, advanced stages of HNSCC and tobacco plus alcohol habits (p<0.05). Hence, we conclude that the distribution of mutations of PIK3CA in HNSCC were associated with demographic (tobacco and alcohol) and clinical parameters (advanced stage, primary site) of HNSCC. It is possible that when this pathway is overactive due to mutations, it may reduce apoptosis and allow proliferation of the tumor cells. Therefore we propose that these mutations may serve as prognostic biomarkers, and can also be proposed as novel therapeutic targets for HNSCC.

KEYWORDS

PI3 kinase, gene polymorphism, helical domain, kinase domain, oral cancers.

Convalescence advice following gynaecological surgery

This was a survey, undertaken in the UK, which was sent to all obstetricians and gynaecologists. The aim was to establish the current advice given for activities during convalescence after commonly performed benign gynaecological surgery. Questionnaires were sent to all the obstetricians and gynaecologists working in 235 NHS hospitals in the UK. The total response rate was 30.51%. There is substantial variability in the advice for activities during convalescence following gynaecological surgery. This has enormous implications - mainly financial. The economic impact of absence from work is enormous. One extra day of sick leave given to patients has a direct cost of approximately £34 million annually. Our survey highlights the need for structured and evidence-based recommendations for convalescence activities following benign gynaecological surgery.

Analysis of the action of euxanthone, a plant-derived compound that stimulates neurite outgrowth

We have investigated the neurite growth-stimulating properties of euxanthone, a xanthone derivative isolated from the Chinese medicinal plant Polygala caudata. Euxanthone was shown to exert a marked stimulatory action on neurite outgrowth from chick embryo dorsal root ganglia explanted in collagen gels, in the absence of added neurotrophins. It was also shown to promote cell survival in explanted chick embryo ganglia, and to stimulate neurite outgrowth from isolated adult rat primary sensory neurons in vitro. The further finding that euxanthone stimulates neurite outgrowth from explants of chick embryo retina and ventral spinal cord suggests an action on signaling pathways downstream of neuronal receptors for specific neurotrophic factors. Consistent with this, euxanthone did not promote neurite outgrowth from non-transfected PC12 cells, or from PC12 cells transfected with TrkB or TrkC, under conditions in which these cells extended neurites in response to, respectively, the neurotrophins nerve growth factor, brain-derived neurotrophic factor and neurotrophin 3. Western blot analysis of euxanthone-stimulated dorsal root ganglion explants showed that expression of phospho-mitogen-activated protein (MAP) kinase was up-regulated after 1 h of euxanthone-treatment. Inhibition of the MAP kinase pathway using PD98059, a specific inhibitor of MAP kinase kinase, blocked all euxanthone-stimulated neurite outgrowth. However, analysis of phospho-Akt expression indicated that the phosphatidylinositol-3 kinase-Akt pathway, another major signaling pathway engaged by neurotrophins, is not significantly activated by euxanthone. These results suggest that euxanthone promotes neurite outgrowth by selectively activating the MAP kinase pathway.

Protection of chemo-radiation therapy induced oral mucositis (OM) in pre-clinical and clinical studies

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Background: D-methionine, was shown to selectively protect normal but not tumor cells from loss of mitochondrial integrity and viability in response to ionizing radiation. OM is a debilitating complication of radiotherapy (RT) and chemotherapy (CT). MRx-1024, a orally bio-available formulation of this agent was evaluated as a treatment for the protection of OM. Methods: A mouse model of radiation-induced lip erythema was used to evaluate the efficacy of MRx-1024. Pharmacokinetic profile of MRX-1024 in healthy human volunteers as well as evaluation of oral MRX-1024 was accomplished in patients (pts) with head and neck cancer receiving RT or RT+CT. Pts received 1.8–2.0 Gy of RT daily for 5 days each week, to a total of 60 Gy. Selected pts also received cisplatin, 50mg/m2 weekly. MRX-1024 suspension was given 1 hour before and again after each RT fraction. Pts were evaluated weekly using 4 accepted scales for assessing OM. Results: A significant protection of radiation-induced lip erythema was achieved in pre-clinical studies without compromising tumor control. Plasma concentrations of MRx-1024 achieved in normal volunteers after oral administration were similar to those required for efficacy in pre-clinical studies. No major adverse events were attributed to MRx-1024. The incidence of OM from 21 evaluable pts was compared with historical controls from the same institution. MRX-1024 was found to be a safe, easily administered and well-tolerated agent that completely ameliorated the incidence of Grade 4 (21% in historical controls) and reduced the incidence of Grade 3 by 80% over historical controls. In addition, preliminary analysis indicated that MRX-1024 did not compromise antitumor activity. Conclusions: These pre-clinical and clinical studies provide exciting proof of principle evidence for the use of MRx-1024 in the treatment of OM. Follow-up clinical studies are underway to further validate these results.

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Oral misoprostol in the third stage of labor

OBJECTIVE

To compare the efficacy of intravenous ergometrine, intramuscular oxytocin, and oral misoprostol in the control of postpartum hemorrhage.

METHODS

Mean blood loss, rates of blood loss between 500 and 1000 ml, hematocrit fall greater than 10%, and need for additional oxytocic agents and nature and rates of adverse effects were assessed in this prospective, randomized, controlled study.

RESULTS

All outcomes were similar in the 3 groups. The main adverse effects in the misoprostol group were temperatures higher than 99 degrees F, which normalized within 2 h and shivering, which was mild and self-limiting.

CONCLUSIONS

Oral misoprostol is as effective as conventional oxytocic agents in preventing postpartum hemorrhage and can be recommended for use in low-resource settings.

Selective surgical management of zone II gunshot injuries of the neck: a prospective study

BACKGROUND

The management of penetrating neck trauma remains controversial, with many studies supporting either mandatory exploration or selective conservatism.

METHODS AND RESULTS

This is a prospective study of 75 patients with gunshot injuries to zone II of the neck. Forty patients (53.3%) underwent immediate exploration because of clinical indications or positive initial investigations. A 7.5% incidence of unnecessary explorations, a 5% mortality rate, and average hospital stay of 10.5 days were noted. Thirty-five patients with negative clinical or investigational findings underwent observation with constant monitoring. A 5.7% incidence of missed injuries, no mortality, and an average hospital stay of 3.5 days were noted for these patients.

CONCLUSIONS

We suggest that conservative management in gunshot injuries confined to zone II of the neck selectively supplemented by appropriate investigations is a viable proposition in this type of injury. Further contemporary studies reporting specifically on this injury will enable us to reach statistically significant conclusions.

Effect of local cooling on skin temperature and blood flow of men in Antarctica

Alterations to the finger skin temperature (Tsk) and blood flow (FBF) before and after cold immersion on exposure to an Antarctic environment for 8 weeks were studied in 64 subjects. There was a significant fall in Tsk and increase in finger blood flow after 1 week of Antarctic exposure. The Tsk did not further change even after 8 weeks of stay in Antarctica but a significant increase in FBF was obtained after 8 weeks. The cold immersion test was performed at non-Antarctic and Antarctic conditions by immersing the hand for 2 min in 0-4 degrees C cold water. In the non-Antarctic environment the Tsk and FBF dropped significantly (P < 0.001) indicating a vasoconstriction response. Interestingly after 8 weeks of stay in Antarctic conditions, the skin temperature dropped (P < 0.001) but the cold induced fall in FBF was inhibited. Based on these observations it may be hypothesized that continuous cold exposure in Antarctica results in vasodilatation, which overrides the stronger vasoactive response of acute cold exposure and thus prevents cold injuries.