IPMICALC: an Integrated Post-mortem Interval Calculator.

Correctly estimating the post-mortem interval (PMI) is essential in forensic practice. In recent decades, the measurement of vitreous humor analyte concentrations - especially of hypoxanthine and potassium - and their correlation with the PMI have returned good results. However, calculating the PMI from the data collected can be quite complex. The present paper describes a web resource ( http://modestya.usc.es:3838/Forensic/ ) that simplifies the procedure. The PMI is determined (with its 95% confidence interval) in a rapid, easy, and reliable manner based on the use of mathematical models, the biochemistry of the vitreous humor, and physical variables such as the ambient temperature, the rectal temperature, and bodyweight. The application is entirely free to use.

The biochemistry of the vitreous humour in estimating the post-mortem interval-a review of the literature, and use in forensic practice in Galicia (northwestern Spain).

The K+ and hypoxanthine (Hx) concentrations of the vitreous humour (VH) rise gradually after death, providing a means of estimating the post-mortem interval (PMI). The correlation between these analytes and the PMI is good since the vitreous chamber is partially isolated from autolytic events occurring elsewhere; the [K +] and [Hx] recorded is thus the result of changes within the eye. The present work provides a systematic review, following PRISMA recommendations, of 36 articles (3 reviews and 33 retrospective cohort studies) discussing the many procedures and regression models that have been developed for improving PMI estimates involving VH analytes. The results of a descriptive study are also provided, highlighting the causes and distribution of mortality as registered in medico-legal autopsies performed in 2019 in Galicia (northwestern Spain), and revealing the use of these PMI estimation methods in real forensic practice. Great heterogeneity was detected in the collection of VH samples, the treatments to which they were subjected before examination, and in their conservation and analysis. A lack of reproducibility in the analytical methods employed to estimate [K +] and [Hx] was noted, as well as an absence of external validation for most of the regression formulae used to determine the PMI from analyte values. The use of methods based on high-performance liquid chromatography, focal electrophoresis, or thermogravimetric/chemometric procedures might solve the problems encountered with traditional analytical techniques, offering reliable results more quickly and effectively (even when samples are contaminated). This study recommends using flexible multiple regression models that combine physical and chemical variables, and that population databases be constructed so that models can be properly validated.

Estimation of the post-mortem interval: Effect of storage conditions on the determination of vitreous humour [K+].

Obtaining a reliable estimate of the post-mortem interval (PMI) has been a long-running challenge in forensic medicine. Several more or less successful techniques for making such estimates have been developed, but in recent years important advances have been made thanks to the detailed study of the relationship between the PMI and the analytes - in particular K+ - of the vitreous humour (VH). The extraction and pre-treatment of VH samples has been standardized, the influence of certain environmental factors on analytical results has been quantified, and some of the circumstances under which techniques become unreliable have been identified. The present work examines how the conditions to which VH samples are subject in routine practice may alter the results of their analysis. Exposure to light and ambient temperature was found to alter the values returned in determinations of VH [K+], [Na+] and [Cl-], while exposure to several freezing/thawing cycles (even with final heating) led to no significant modifications in determinations of VH [K+] and [Na+]. It is recommended that if analysis has to be delayed, VH should be frozen for storage in a refrigerator before bringing to room temperature for processing. It is also recommended that samples not be exposed to ambient light and temperature.

A reliable method for estimating the postmortem interval from the biochemistry of the vitreous humor, temperature and body weight.

The estimation of the time elapsed since death is of paramount importance in the field of forensic sciences and criminal investigation, owing, among other factors, to the possible legal repercussions. Over the past few years various formulae have been developed to calculate this interval using a combination of different statistical methods and the concentrations of substances found in the vitreous humor. Corrective factors, such as ambient temperature, cause of death or age, which can modify the concentration of these substances and therefore the estimation of the postmortem interval, have been incorporated into models. In this paper five simple and reliable models to estimate PMI based the on the analysis of potassium, hypoxanthine and urea in the vitreous humor are presented. Corrective factors, such as body weight, rectal temperature and ambient temperature, which can influence the estimation of this interval have been incorporated into the formulae. Finally, the R2 and the mean squared error have been calculated for each model in order to select the best of the five. A free software program which calculates the PMI from the model and parameters used is available from the authors. It provides quick and reliable results as well as the error committed and R2 for each case.

Resting metabolic rate of obese patients under very low calorie ketogenic diet.

BACKGROUND: The resting metabolic rate (RMR) decrease, observed after an obesity reduction therapy is a determinant of a short-time weight regain. Thus, the objective of this study was to evaluate changes in RMR, and the associated hormonal alterations in obese patients with a very low-calorie ketogenic (VLCK)-diet induced severe body weight (BW) loss. METHOD: From 20 obese patients who lost 20.2 kg of BW after a 4-months VLCK-diet, blood samples and body composition analysis, determined by DXA and MF-Bioimpedance, and RMR by indirect calorimetry, were obtained on four subsequent visits: visit C-1, basal, initial fat mass (FM) and free fat mass (FFM); visit C-2, - 7.2 kg in FM, - 4.3 kg in FFM, maximal ketosis; visit C-3, - 14.4 kg FM, - 4.5 kg FFM, low ketosis; visit C-4, - 16.5 kg FM, - 3.8 kg FFM, no ketosis. Each subject acted as his own control. RESULTS: Despite the large BW reduction, measured RMR varied from basal visit C-1 to visit C-2, - 1.0%; visit C-3, - 2.4% and visit C-4, - 8.0%, without statistical significance. No metabolic adaptation was observed. The absent reduction in RMR was not due to increased sympathetic tone, as thyroid hormones, catecholamines, and leptin were reduced at any visit from baseline. Under regression analysis FFM, adjusted by levels of ketonic bodies, was the only predictor of the RMR changes (R2 = 0.36; p < 0.001). CONCLUSION: The rapid and sustained weight and FM loss induced by VLCK-diet in obese subjects did not induce the expected reduction in RMR, probably due to the preservation of lean mass. TRIAL REGISTRATION: This is a follow up study on a published clinical trial.

Predictive models for the assessment of bodily harm.

The Spanish scale to quantify or qualify bodily harm resulting from any unintentional traffic accident prior to 1 January 2016 is established by Royal Legislative Decree (RDL) 8/2004. This scale assigns points to the sequelae, which are converted into Euros using a table that is updated annually. The objective of this study is to develop a predictive model of sequelae points that will enable the estimation of compensation a short time after the accident. This will facilitate the calculation of the money reserve and rapid access to compensation for the injured party. To conduct this study, we developed a database with information from 999 individuals who had suffered car crash injuries which were evaluated according to the scale contained in RDL 8/2004 for medical experts. Predictive models based on logistic regression models were designed on this database. To choose the best model, we calculated Mallow's Cp. The use of hurdle models made it possible to predict the points received by an injured party within a relatively short period of time after the accident. Once these points are known, it is a simple matter to calculate the corresponding compensation. The prediction models developed provide an easy way to predict the compensation to be awarded to the injured party. These models use days of hospitalization, sex, age and the results of international scales based on the Abbreviated Injury Scale. These variables can be used soon after the occurrence of the crash.

Body Composition Changes After Very-Low-Calorie Ketogenic Diet in Obesity Evaluated by 3 Standardized Methods.

Context: Common concerns when using low-calorie diets as a treatment for obesity are the reduction in fat-free mass, mostly muscular mass, that occurs together with the fat mass (FM) loss, and determining the best methodologies to evaluate body composition changes. Objective: This study aimed to evaluate the very-low-calorie ketogenic (VLCK) diet-induced changes in body composition of obese patients and to compare 3 different methodologies used to evaluate those changes. Design: Twenty obese patients followed a VLCK diet for 4 months. Body composition assessment was performed by dual-energy X-ray absorptiometry (DXA), multifrequency bioelectrical impedance (MF-BIA), and air displacement plethysmography (ADP) techniques. Muscular strength was also assessed. Measurements were performed at 4 points matched with the ketotic phases (basal, maximum ketosis, ketosis declining, and out of ketosis). Results: After 4 months the VLCK diet induced a -20.2 ± 4.5 kg weight loss, at expenses of reductions in fat mass (FM) of -16.5 ± 5.1 kg (DXA), -18.2 ± 5.8 kg (MF-BIA), and -17.7 ± 9.9 kg (ADP). A substantial decrease was also observed in the visceral FM. The mild but marked reduction in fat-free mass occurred at maximum ketosis, primarily as a result of changes in total body water, and was recovered thereafter. No changes in muscle strength were observed. A strong correlation was evidenced between the 3 methods of assessing body composition. Conclusion: The VLCK diet-induced weight loss was mainly at the expense of FM and visceral mass; muscle mass and strength were preserved. Of the 3 body composition techniques used, the MF-BIA method seems more convenient in the clinical setting.

Type 1 familial partial lipodystrophy: understanding the Köbberling syndrome.

Familial partial lipodystrophy are Mendelian disorders involving abnormal body fat distribution and insulin resistance. The current classification includes the Köbberling syndrome (type 1 familial partial lipodystrophy), characterized by fat loss in the lower limbs and abnormal fat accumulation in other areas. Type 1 familial partial lipodystrophy appears to be heritable, but little is known about it, including putative contributing mutations. We aimed to characterize this syndrome better by evaluating a group of women with phenotypic features of type 1 familial partial lipodystrophy. This is a case-controlled study in which 98 women with type 1 familial partial lipodystrophy that lacked classical mutations known to cause familial partial lipodystrophy were compared with 60 women without lipodystrophy and 25 patients with type 2 familial partial lipodystrophy (Dunnigan disease). Clinical course, body composition by dual-energy X-ray absorptiometry, HbA1c, lipid profile, insulin, leptin and family history were evaluated in all of the participants. Analyses of receiver-operating characteristic curve were performed for type 1 familial partial lipodystrophy diagnosis, comparing different truncal/limbs ratios. Among patients with type 1 familial partial lipodystrophy, 68 % developed recognizable lipodystrophy before adolescence, and most displayed an autosomal-dominant pattern (86 %). Women with type 1 familial partial lipodystrophy had less lower-limb adipose tissue than women without lipodystrophy, but significantly more than patients with Dunnigan disease. Moreover, metabolic disturbances occurred more frequently in the type 1 familial partial lipodystrophy group (81 %) than in the non-lipodystrophic group (30 %, p<0.05). The severity of metabolic disturbances was inversely proportional to the percentage of fat in the lower extremities and directly proportional to the amount of visceral adipose tissue. Metabolic profiles were worse in type 1 familial partial lipodystrophy than in Dunnigan disease. According to the receiver-operating characteristic curve analysis, the best ratio was subscapular/calf skinfolds (KöB index), with a cut-off value of 3.477 (sensitivity: 89 %; specificity: 84 %). Type 1 familial partial lipodystrophy was an early-onset, autosomal-dominant lipodystrophy, characterized by fat loss in the lower limbs and abnormal fat accumulation in the abdominal visceral region, associated to insulin resistance and metabolic disorders. A KöB index >3.477 is highly suggestive of this syndrome.

How reliable is the Spanish bodily harm assessment scale?

The use of scales to quantify or qualify bodily harm resulting from an unintentional car accident has been mandatory in Spain since 1995 and compensation for personal injuries resulting from a traffic accident is calculated according to a legal ruling established by Royal Decree 8/2004 (RDL). This present study assesses the reliability of the scale. Agreement between the evaluations for the same patient by 24 qualified observers following the Royal Decree 8/2004 was measured using the Kappa index. The variables assessed were the days of hospitalization, impeditive days, non impeditive days and the functional and aesthetic sequelae. The application of the Fleiss Kappa index obtained a result of 0.37, indicating a "fair agreement" according to the rating scale proposed by Landis and Koch. This study demonstrates the unreliability of the Spanish medical scale for the assessment of injury as described in the RDL 8/2004. The scale should adopt the measurement systems and clinical classifications of outcomes such as the ASIA, SCI scale or the Daniels scale of neurological injury and allow scientific discussion of the findings of the report. The resulting quantitative value should operate as a reliable indicator of a specific quality of the damage.