Update of the PANCCO clinical practice guidelines for the treatment of ulcerative colitis in the adult population

Ulcerative colitis (US) is a chronic disease of unknown etiology. It is incurable and its clinical course is intermittent, characterized by periods of remission and relapse. The prevalence and incidence of the disease has been increasing worldwide. The update presented herein includes the participation of healthcare professionals, decision-makers, and a representative of the patients, all of whom declared their conflicts of interest. Answerable clinical questions were formulated, and the outcomes were graded. The information search was conducted on the Medline/PubMed, Embase, Epistemonikos, and LILACS databases, and covered grey literature sources, as well. The search was updated on November 30, 2020, with no restrictions regarding date or language. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification system was implemented to establish the strength of the recommendation and quality of evidence. A formal consensus was developed, based on the RAND/UCLA methodology and the document was peer reviewed. The short version of the Clinical Practice Guidelines for the Treatment of Ulcerative Colitis in the Adult Population is presented herein, together with the supporting evidence and respective recommendations. In mild-to-moderate UC, budesonide MMX is an option when treatment with 5-ASA fails, and before using systemic steroids. In moderate-to-severe UC, infliximab, adalimumab, vedolizumab, ustekinumab, and tofacitinib can be used as first-line therapy. If there is anti-TNF therapy failure, ustekinumab and tofacitinib provide the best results. In patients with antibiotic-refractory pouchitis, anti-TNFs are the treatment of choice.

Haptic simulation of tissue tearing during surgery

We present a method for the real-time, interactive simulation of tissue tearing during laparoscopic surgery. The method is designed to work at haptic feedback rates (ie, around 1 kHz). Tissue tearing is simulated under the general framework of continuum damage mechanics. The problem is stated as a general, multidimensional parametric problem, which is solved by means of proper generalized decomposition methods. One of the main novelties is the reduction of history-dependent problems, such as damage mechanics, by resorting to an approach in which a reduced-order field of initial damage values is considered as a parameter of the formulation. We focus on the laparoscopic cholecystectomy procedure as a general example of the performance of the method.

An index with improved diagnostic accuracy for the diagnosis of Crohn's disease derived from the Lennard-Jones criteria

BACKGROUND

The Lennard-Jones criteria are considered the gold standard for diagnosing Crohn's disease (CD) and include the items granuloma, macroscopic discontinuity, transmural inflammation, fibrosis, lymphoid aggregates and discontinuous inflammation on histology. The criteria have never been subjected to a formal validation process.

AIM

To develop a validated and improved diagnostic index based on the items of Lennard-Jones criteria.

METHODS

Included were 328 adult patients with long-standing CD (median disease duration 10 years) from three centres and classified as 'established', 'probable' or 'non-CD' by Lennard-Jones criteria at time of diagnosis. Controls were patients with ulcerative colitis (n = 170). The performance of each of the six diagnostic items of Lennard-Jones criteria was modelled by logistic regression and a new index based on stepwise backward selection and cut-offs was developed. The diagnostic value of the new index was analysed by comparing sensitivity, specificity and accuracy vs. Lennard-Jones criteria.

RESULTS

By Lennard-Jones criteria 49% (n = 162) of CD patients would have been diagnosed as 'non-CD' at time of diagnosis (sensitivity/specificity/accuracy, 'established' CD: 0.34/0.99/0.67; 'probable' CD: 0.51/0.95/0.73). A new index was derived from granuloma, fibrosis, transmural inflammation and macroscopic discontinuity, but excluded lymphoid aggregates and discontinuous inflammation on histology. Our index provided improved diagnostic accuracy for 'established' and 'probable' CD (sensitivity/specificity/accuracy, 'established' CD: 0.45/1/0.72; 'probable' CD: 0.8/0.85/0.82), including the subgroup isolated colonic CD ('probable' CD, new index: 0.73/0.85/0.79; Lennard-Jones criteria: 0.43/0.95/0.69).

CONCLUSION

We developed an index based on items of Lennard-Jones criteria providing improved diagnostic accuracy for the differential diagnosis between CD and UC.

Real-time simulation of biological soft tissues: a PGD approach

We introduce here a novel approach for the numerical simulation of nonlinear, hyperelastic soft tissues at kilohertz feedback rates necessary for haptic rendering. This approach is based upon the use of proper generalized decomposition techniques, a generalization of PODs. Proper generalized decomposition techniques can be considered as a means of a priori model order reduction and provides a physics-based meta-model without the need for prior computer experiments. The suggested strategy is thus composed of an offline phase, in which a general meta-model is computed, and an online evaluation phase in which the results are obtained at real time. Results are provided that show the potential of the proposed technique, together with some benchmark test that shows the accuracy of the method.

Real-time simulation of surgery by reduced-order modeling and X-FEM techniques

This paper describes a novel approach for the simulation of surgery by a combined technique of model order reduction and extended finite element method (X-FEM) methods. Whereas model order reduction techniques employ globally supported (Ritz) shape functions, a combination with X-FEM methods on a locally superimposed patch is developed for cutting simulation without remeshing. This enables to obtain models with very few degrees of freedom that run under real-time constrains even for highly non-linear tissue constitutive equations. To show the performance of the technique, we studied an application to refractive surgery in the cornea.

Accounting for large deformations in real-time simulations of soft tissues based on reduced-order models

Model reduction techniques have shown to constitute a valuable tool for real-time simulation in surgical environments and other fields. However, some limitations, imposed by real-time constraints, have not yet been overcome. One of such limitations is the severe limitation in time (established in 500Hz of frequency for the resolution) that precludes the employ of Newton-like schemes for solving non-linear models as the ones usually employed for modeling biological tissues. In this work we present a technique able to deal with geometrically non-linear models, based on the employ of model reduction techniques, together with an efficient non-linear solver. Examples of the performance of the technique over some examples will be given.

Real-time deformable models of non-linear tissues by model reduction techniques

In this paper we introduce a new technique for the real-time simulation of non-linear tissue behavior based on a model reduction technique known as proper orthogonal (POD) or Karhunen-Loève decompositions. The technique is based upon the construction of a complete model (using finite element modelling or other numerical technique, for instance, but possibly from experimental data) and the extraction and storage of the relevant information in order to construct a model with very few degrees of freedom, but that takes into account the highly non-linear response of most living tissues. We present its application to the simulation of palpation a human cornea and study the limitations and future needs of the proposed technique.

[Inflammatory demyelinating chronic polyneuropathy: a contribution to the characterization of the disease]

INTRODUCTION AND OBJECTIVE

The chronic inflammatory demyelinating polyneuropathy (CIDP) is a controversial sickness. No doubt it is still a diagnosis without a strict nosologic delimitation until we acquire a greater knowledge about the underlying mechanisms, or whether a specific marker is found. We evaluated its clinical and laboratory findings, to contribute to its characterization in our environment.

PATIENTS AND METHODS

We reviewed the records of 37 patients diagnosed with CIDP between 1986 and 1997. They were grouped in as to sex, age, beginning age (BA), evolution time, race, clinical form, symptoms, signs and evolutive profile. We analyzed the cytochemic and immunologic studies of cerebrospinal fluid (CSF) as well as sural nerve biopsy.

RESULTS AND CONCLUSIONS

We demonstrated a predominance of BA between the fifth and sixth decades, and the presentation of a mixed polyradiculoneuropathy with motor predominance and a chronic progressive evolution. It was positively correlated with protein concentration levels in CSF, elevated in the 73.5% of the patients. There was an increase in the permeability of the blood brain barrier (BBB) in 50.8%, IgG intrathecal synthesis in 5.08 and oligoclonal bands in 8.8%. We found lost of myelin sheats in 90.6% of sural nerves and onion-bulbs formation in 60.5%, which demonstrated the high sensitivity of this study to confirm the diagnosis of demyelinating process as essential substrate in the illness.

[Clinical characterization of patients with multiple sclerosis defined in Cuba]

INTRODUCTION

Since 1975 no studies have been done in Cuba defining the clinical characteristics of patients with multiple sclerosis (MS).

OBJECTIVE

To describe the characteristics of a group of Cuban patients with definite clinical MS.

MATERIAL AND METHODS

Fifty eight patients with definite clinical MS were studied (Poser et al) with normal motor (VCM) and sensory (VCS) conduction velocities. Tests were done on them: clinical scale (Scripps), incapacity (EDSS) and quality of life (Steps), together with various complementary tests. Each patient was classified according to the way in which the disease evolved. Also the two commonest clinical types were compared and we applied the difference test between percentages of non-paired samples with an alfa level of 0.05.

RESULTS

Onset of the illness in most cases was before the age of 40 (86.1%), 75.9% were women and 82.8% were white. In 15.3% there was a family history of MS. In 25.9% there were psychiatric disorders and trigger factors (43.1%. The most frequent initial symptoms were pyramidal (48.3%) sensorial (41.4%) and cerebellar (39.7%). Scripps scale scores were < 80 in 60.2%, in EDSS < 5 (61.9%) and in the Clinical Steps < 3 in 65.4%). Motor potentials (81.9%) somatosensory potential (PESS) (72.3%) and magnetic resonance imaging (MR) (76.4%) were the most abnormal results. Exacerbation-remission (ER) was the most frequent type of evolution (53.4%) generally affecting patients aged under 40 years old (p = 0.02), EDSS < 5 (64.4%), Scripps > 80 (61.2%), Steps < 3 (95.6%), pyramidal system involvement (58.5%), cerebellar (29.2%) and MRI abnormality (80%). The progressive primary form (PP) was the second most frequent (29.3%); 29.4% were under 40 years of age, had more marked changes in all functional system (100%), degree of incapacity and quality of life (100%). PESS (92.5%); the urodynamic tests 58.85%) were less positive on MRI (54.5%) as compared with the ER form.

CONCLUSIONS

The differences found between the clinical forms ER and II indicate that there is greater deterioration in the PP form, probably due to age and more cerebellar and spinal cord involvement.