Hatchet flap for distal fingertip amputations.

Purpose: - Fingertip amputations are responsible for significant pain, suffering, discomfort as well as lost productivity and financial and physical hardship. Distal finger tip amputations pose a unique reconstructive challenge as the aim is to provide a supple cover with sensation. Wide variety of options are available for the reconstruction following fingertip amputations. This study evaluates the use of hatchet flap in the management of distal fingertip amputations. Methods: The hatchet flap was done in 35 fingers of 31 patients with fingertip amputations at the level of distal phalanx who presented to our unit, fulfilling the inclusion criteria during a period of 18 months. All transverse and dorsal oblique amputations (of any size) at the level of distal phalanx of any age group were included in the study. Volar fingertip amputations at the level of distal phalanx and fingertip amputations associated with other injury over the volar aspect of finger were excluded from the study. Results: The flap provided a very good padded soft tissue cover with good aesthetic shape to the finger tip. The scars were unnoticeable with an average 2 point discrimination of 6.7 â€‹mm at 12 weeks post operatively. Paresthesia was noted maximally at 1 week post operative duration. Joint stiffness was not noted in any patient. Most patients were able to return back to their normal daily routine at around 3 weeks. Complete flap necrosis was noted in 1 patient while partial tip necrosis was noted in 2 patients. Conclusion: The hatchet flap serves as a good local reconstructive flap option which preserves the tactile sensation and is a valuable addition to the wide armamentarium of reconstructive procedures available for treating the distal fingertip amputations.

External Validation of Three Burn-Specific Mortality Prediction Models in Adult Burn Patients at a Tertiary Care Hospital in India.

Background Several burn-specific mortality prediction models have been formulated and validated in the developed countries. There is a dearth of studies validating these models in the Indian population. Our objective was to validate three such models in the Indian burn patients. Methods A prospective observational study was performed after ethical clearance on consecutive eligible consenting burn patients. Patient demographics, vitals, and results of hematological workup were collected. Using these. the Abbreviated Burn Severity Index (ABSI), the revised Baux score (rBaux), and the Fatality by Longevity, APACHE II score, Measured extent of burn, and Sex score (FLAMES) were calculated. The discriminative ability of the ABSI, rBaux, and the FLAMES was tested using the receiver operating characteristic (ROC) curve at 30 days and the area under the ROC curve (AUROC) compared. A p -value ≤ 0.05 was considered significant. Probability of death was calculated using these models. Hosmer-Lemeshow goodness of fit test was run. Results The ABSI (AUROC 0.7497, 95% CI 0.67796-0.82141), rBaux (AUROC 0.7456, 95% CI 0.67059-0.82068) and FLAMES (AUROC 0.7119, 95% CI 0.63209-0.79172), had fair discriminative ability. The Hosmer-Lemeshow test reported that ABSI and rBaux were a good fit for the Indian population, while FLAMES was not a good fit. Conclusion The ABSI and rBaux had a fair discriminative ability and were a good fit for the adult patients with 30 to 60% thermal and scald burn patients. FLAMES despite having fair discriminative ability was not a good fit for the study population.

Predicting Burn Mortality Using a Simple Novel Prediction Model.

Background Prediction of outcome for burn patients allows appropriate allocation of resources and prognostication. There is a paucity of simple to use burn-specific mortality prediction models which consider both endogenous and exogenous factors. Our objective was to create such a model. Methods A prospective observational study was performed on consecutive eligible consenting burns patients. Demographic data, total burn surface area (TBSA), results of complete blood count, kidney function test, and arterial blood gas analysis were collected. The quantitative variables were compared using the unpaired student t -test/nonparametric Mann Whitney U-test. Qualitative variables were compared using the ⊠2-test/Fischer exact test. Binary logistic regression analysis was done and a logit score was derived and simplified. The discrimination of these models was tested using the receiver operating characteristic curve; calibration was checked using the Hosmer-Lemeshow goodness of fit statistic, and the probability of death calculated. Validation was done using the bootstrapping technique in 5,000 samples. A p -value of <0.05 was considered significant. Results On univariate analysis TBSA ( p <0.001) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score ( p = 0.004) were found to be independent predictors of mortality. TBSA (odds ratio [OR] 1.094, 95% confidence interval [CI] 1.037-1.155, p = 0.001) and APACHE II (OR 1.166, 95% CI 1.034-1.313, p = 0.012) retained significance on binary logistic regression analysis. The prediction model devised performed well (area under the receiver operating characteristic 0.778, 95% CI 0.681-0.875). Conclusion The prediction of mortality can be done accurately at the bedside using TBSA and APACHE II score.

Comparative evaluation of three methods of skin graft fixation for split thickness skin graft after release of post burn contracture of the neck.

OBJECTIVES: Split thickness skin graft is an essential component of release of post burn contracture of neck. There are many methods of fixation of skin grafts; however, there is lack of objective comparison between different techniques. This study has been designed to compare three commonly used techniques of split thickness skin graft fixation methods. Surgical time, advantages, cost factor and post-operative outcome have been compared amongst three techniques. METHODS: A randomized interventional comparative study was conducted to compare three methods of skin graft fixation in patients of 10-50 years age group, with contracture of more than 3 month duration having more than 100cm2 skin defects after contracture release. Resurfacing of the defects after contracture release was carried out in all the groups using autologous split skin grafts. Patients were included in three groups; Group 1: tie over method, Group 2: skin stapler fixation and Group 3: Cyanoacrylate glue fixation. RESULTS: Mean duration of fixation procedure was 34min in tie over group, in skin stapler group 7min and in cyanoacrylate group 12min. Mean cost of fixation material was 10.23 USD in tie-over group, 11.23 USD in stapler group and 40.06 USD in cyanoacrylate group. Mean score of pain/discomfort (visual analog score) on dressing removal in tie-over group was 3, for skin stapler group was 2.9 and that for cyanoacrylate glue group was 1.8. mean graft take was found to be 90.1% in tie-over group, 94.1% in skin stapler group & 93.8% in cyanoacrylate glue group. On logistic regression analysis, keeping all the variables constant in the groups the complications as the outcome variable, three groups are comparable. The need for regrafting remains inconclusive. CONCLUSIONS: Skin stapler method for skin graft fixation was least time consuming, affordable and highly reliable when graft take success was considered. Cyanoacrylate glue fixation method was least painful and reliable in terms of graft take success though costlier than other two.

Stereo specific platelet inhibition by the natural LXR agonist 22(R)-OH-cholesterol and its fluorescence labelling with preserved bioactivity and chiral handling in macrophages.

Two synthetic LXR agonists were recently reported to inhibit collagen-induced platelet aggregation and thrombus formation in mice. We therefore studied whether also natural LXR agonists inhibit human platelet activation and whether they can be fluorescence-labelled preserving their bioactivity for LXR-related functional imaging. The natural LXR agonist 22(R)-OH-cholesterol - but not its stereoisomer 22(S)-OH-cholesterol - inhibited collagen induced platelet shape change and aggregation similar to synthetic LXR agonists in a concentration- and time-dependent manner. First exposure to 22(S)-OH-cholesterol prevented the subsequent inhibition of platelets by 22(R)-OH-cholesterol but not vice versa. 22(R)- and 22(S)-OH-cholesterol could be fluorescence-labelled as 22(R)- and 22(S)-OH-cholesteryl-3-dodecanoic-3-BODIPY esters with high yield and purity using the Steglich acylation. Labelled 22(R)- and 22(S)-OH-cholesterol esters retained the stereo specific bioactivity of their parent compounds, were metabolically stable and not cytotoxic at LXR agonistic concentrations. Live staining with labelled 22(R)- or 22(S)-OH-cholesterol esters demonstrated stereo specific inhibition of platelet spreading and chiral handling by macrophages that reflect LXR activation. The rapid inhibition of platelet reactivity to collagen by natural and pharmacologic LXR agonists offers a mechanism that could attenuate platelet activation by denuded plaques that expose collagen and LXR agonistic oxysterols. Stable fluorescence labelled 22(R)- and 22(S)-OH-cholesterol analogues with preserved stereo specific bioactivity and staining characteristics provide valuable tools for LXR-related functional imaging in pathophysiologic studies, for binding assays and for LXR-targeted drug development.

Annelated pyridines as highly nucleophilic and Lewis basic catalysts for acylation reactions.

New heterocyclic derivatives of 9-azajulolidine have been synthesized and characterized with respect to their nucleophilicity and Lewis basicity. The Lewis basicity of these bases as quantified through their theoretically calculated methyl-cation affinities correlate well with the experimentally measured reaction rates for addition to benzhydryl cations. All newly synthesized pyridines show exceptional catalytic activities in benchmark acylation reactions, which correlate only poorly with Lewis basicity or nucleophilicity parameters. A combination of Lewis basicity with charge and geometric parameters in the framework of a three-component quantitative structure-activity relationship (QSAR) model is, however, highly predictive.

Cation affinity numbers of Lewis bases.

Using selected theoretical methods the affinity of a large range of Lewis bases towards model cations has been quantified. The range of model cations includes the methyl cation as the smallest carbon-centered electrophile, the benzhydryl and trityl cations as models for electrophilic substrates encountered in Lewis base-catalyzed synthetic procedures, and the acetyl cation as a substrate model for acyl-transfer reactions. Affinities towards these cationic electrophiles are complemented by data for Lewis-base addition to Michael acceptors as prototypical neutral electrophiles.

The aza-Morita-Baylis-Hillman reaction of electronically and sterically deactivated substrates.

The aza-Morita-Baylis-Hillman (azaMBH) reaction has been studied for electronically and sterically deactivated Michael acceptors. It is found that electronically deactivated systems can be converted with electron-rich phosphanes and pyridines as catalysts equally well. For sterically deactivated systems clearly better catalytic turnover can be achieved with pyridine catalysts. This is in accordance with the calculated affinities of the catalysts towards different Michael-acceptors.

Supragaleal placement of tissue expander for post-burn alopecia.

Supragaleal placement of tissue expander for management of alopecia of scalp excludes tough galeal layer so that easier and faster expansion of scalp may be achieved.