Tumor growth for remodeling process: A 2D approach

This paper aims to present a comprehensive framework for coupling tumor-bone remodeling processes in a 2-dimensional geometry. This is achieved by introducing a bio-inspired damage that represents the growing tumor, which subsequently affects the main populations involved in the remodeling process, namely, osteoclasts, osteoblasts, and bone tissue. The model is constructed using a set of differential equations based on the Komarova's and Ayati's models, modified to incorporate the bio-inspired damage that may result in tumor mass formation. Three distinct models were developed. The first two models are based on the Komarova's governing equations, with one demonstrating an osteolytic behavior and the second one an osteoblastic model. The third model is a variation of Ayati's model, where the bio-inspired damage is induced through the paracrine and autocrine parameters, exhibiting an osteolytic behavior. The obtained results are consistent with existing literature, leading us to believe that our in-silico experiments will serve as a cornerstone for paving the way towards targeted interventions and personalized treatment strategies, ultimately improving the quality of life for those affected by these conditions.

Attitudes scale toward cancer-related cognitive changes - an initial Colombian validation

OBJECTIVE

The aim of this study was to develop an initial valid tool to measure attitudes toward cancer-related cognitive changes.

SUBJECTS AND METHODS

After revising the literature, three main dimensions were hypothesized. Eight judges were contacted to obtain content validity evidence. A robust Exploratory Factor Analysis (EFA) was performed via a parallel analysis with an Unweighted Least Squares (ULS) estimator and polychoric correlations. The results were crossed with sociodemographic variables to find possible statistical differences and estimate the size effect. Analysis was performed in the software Factor and the statistical package R.

RESULTS

A sample of 374 participants was obtained, involving oncology patients, their caregivers, and people from the general community. A statistical fit was found in two dimensions: Awareness and Judgments [root mean squared error of approximation (RMSEA) = 0.042, standardized root mean square residual (SRMR) = 0.02, comparative fit index (CFI) = 0.99, Tucker-Lewis index (TLI) = 0.98] with a moderate correlation between them (r = 0.612). Optimal reliability indices were obtained for the total scale and its dimensions. No real statistical difference was found between sociodemographic variables; the interpretation norms were established via the quartiles.

CONCLUSIONS

The first attempt to measure the construct of interest was developed with two primary validity evidence based on the content and its internal structure. This instrument could help strengthen the prevention of cancer-related cognitive changes. More research is needed to adhere more valid evidence to the scale.

A coupled mathematical model between bone remodeling and tumors: a study of different scenarios using Komarova's model

This paper aims to construct a general framework of coupling tumor-bone remodeling processes in order to produce plausible outcomes of the effects of tumors on the number of osteoclasts, osteoblasts, and the frequency of the bone turnover cycle. In this document, Komarova's model has been extended to include the effect of tumors on the bone remodeling processes. Thus, we explored three alternatives for coupling tumor presence into Komarova's model: first, using a "damage" parameter that depends on the tumor cell concentration. A second model follows the original structure of Komarova, including the tumor presence in those equations powered up to a new parameter, called the paracrine effect of the tumor on osteoclasts and osteoblasts; the last model is replicated from Ayati and collaborators in which the impact of the tumor is included into the paracrine parameters. Through the models, we studied their stability and considered some examples that can reproduce the tumor effects seen in clinic and experimentally. Therefore, this paper has three parts: the exposition of the three models, the results and discussion (where we explore some aspects and examples of the solution of the models), and the conclusion.

[Morbidity and mortality of surgically treated proximal humerus fractures]

BACKGROUND

The aim of the present study is to analyse the factors associated with mortality and the capacity to perform daily life activities (DLA) in patients with surgically treated proximal humeral fractures.

METHODS

A retrospective study was conducted on 94 patients with a surgically treated proximal humeral fracture, with a mean follow-up of 8 years (2 - 12 years). A correlation analysis was performed to determine the relationship between the type of fracture, surgical technique, comorbidities and mortality and DLA. The Student t test was used for statistical analysis.

RESULTS

A total of 72 patients were identified, 18.6% of them died during follow-up, all diagnosed with some comorbidity. There was no correlation between mortality, type of fracture or the technique used. Most of the patients (85.4%) had comorbidities, and 79.5% were completely independent for DLA. Although there was no relationship with the type of fracture, there was a significant reduction in the performing of DLA in patients treated with hemiarthroplasty, and in patients with neurological disorders.

CONCLUSIONS

There was a mortality of 18.6% among patients with surgically treated proximal humerus fractures. The majority of surgically treated patients were fully independent for DLA at long-term follow-up.

[Chickenpox outbreak in Herrera del Duque, Badajoz, Spain]

INTRODUCTION

Chickenpox is a worldwide disease with high morbidity but few complications, although complications can be sevre in immunocompromised individuals and healthy adults. The annual chickenpox rate declared to the National Notification Disease Surveillance System is approximately 5 cases per 1,000 inhabitants in Extremadura (Spain). The aim of this study was to identify and describe the characteristics and cost of an epidemic outbreak of chickenpox in Extremadura.

METHODS

Between November 2000 and March 2001, a descriptive study was performed. Cases of chickenpox were actively sought in a cohort of schoolchildren in Herrera del Duque (Badajoz). The protocols of the Monitoring Network of the Autonomous Community of Extremadura was used for case definition. Microbiological confirmation was performed by isolation of the virus and the presence of IgM and IgG markers in serum. We analyzed the direct and indirect tangible costs as well as the intangible costs of the outbreak.

RESULTS

Seventy-five cases were identified, of which 94.7% occurred in children aged between 1-9 years, mainly boys. The attack rate was 18.5 cases per 1,000 inhabitants and 68.2% occurred in children aged less than 10 years charing a home. The clinical course was benign, without hospital admissions or complications. A total of 71.6% of children aged between 3 and 8 years were susceptible. A possible temporary aggregation of cases in the school was analyzed and a relative risk of 5.01 (p < 0.0001) was obtained. The virus was isolated in the 4 vesicle samples studied and serology was positive (IgM) in the 9 serum samples studied. The total cost of the outbreak was of 927,21 e, with a mean of 12,53 e per case and 205 school days lost.

CONCLUSION

A chickenpox outbreack was confirmed in Herrera del Duque, with person-to-person transmission, affecting children aged between 1 and 9 years. The high susceptibility of the pupils, the characteristics of teaching, and the meetings prior to the carnivals played a determining role in the transmission of the epidemic. The estimated cost of this outbreak was 76% less than the cost that would have been generated by single-dose vaccination of the 75 individuals who contracted the disease.

[Diabetes insipidus as a manifestation of cerebral toxoplasmosis in an AIDS patient]

INTRODUCTION

In AIDS patients the endocrine system is often affected. Diabetes insipidus (DI) is uncommon and has been related to drugs and infections of the central nervous system (toxoplasmosis, cryptococcic meningitis, cytomegalovirus encephalitis). In these patients at the time of diagnosis, imaging investigations are often normal.

CLINICAL CASE

We report the case of a 40 year old man with infection category HIV C3 (CD4 < 50 mm3 and viral load 301,258 copies/ml), not on antiretroviral treatment at the time of hospital admission. He had polyuria (8-10 litres/day) and polydipsia for the previous 15 days, with no other symptoms. The dehydration test showed central DI (raised osmolarity following subcutaneous desmopresin). On MNR there were bilateral periventricular nodular images, also present in both caudate nuclei, with ring increased uptake following administration of paramagnetic contrast. On the clinical suspicion of cerebral toxoplasmosis empirical treatment was started with sulphadiazine and pyrimethamine together with nasal DDAVP, obtaining a good clinical response.

CONCLUSIONS

In patients with HIV infection, DI, although uncommon, may be the first sign of cerebral toxoplasmosis. Imaging studies may be pathological and assist diagnosis.

[Neurology and the reform of the health care system in Colombia]

INTRODUCTION AND OBJECTIVES

Despite the magnitude of the Colombian health system reform, introduced in 1993, changes in specialized medical practice have not been evaluated. This paper is the follow-up of a similar study on the practice of neurology done by the authors before the reform.

MATERIAL AND METHODS

Of the 62 members of the Colombian Association of Neurology living in Bogotá, 47 (76%) of them responded an anonymous survey inquiring on the characteristics of their medical practice and registering all the medical encounters during one week in October 1998.

RESULTS

Two thirds of the total working time is devoted by neurologists to clinical work. Half of the neurologists in the sample have invested in diagnostic equipment. There was no significant change in the total number of patients attended during the week, as compared with the 1993 study, and the diagnostic profile was similar. The proportion of private patients was significantly lower, while patients from prepaid medical schemes increased. Patients belonging to the Obligatory Health Plan, designed to cover lowest income population, and to prepaid medicine are not distributed homogeneously throughout all ages. The first year of life is particularly uncovered by the Obligatory Health Plan, while prepaid schemes do not address the problems of individuals age 60 or more.

CONCLUSIONS

There has been a significant reduction in private practice compensated by an increase in prepaid medicine. There is no evidence of increased coverage for neurological disorders.

[Antithrombotic treatment in non-rheumatic atrial fibrillation. Do we follow the recommendations of clinical trials?]

OBJECTIVES

Several clinical trials have demonstrated that antithrombotic treatment may be effective in prevention of stroke in nonrheumatic atrial fibrillation (AF). The aim of this study was to assess if we follow clinical trial recommendations in community practice.

METHODS

We analyzed 225 medical records of patients diagnosed of nonrheumatic AF in Cáceres, during February and March 1998. Patients who were contraindicated to follow antiagreggation or anti-coagulation treatment were excluded. We compared patients with and without antithrombotic treatment with different demographic characteristics and embolic risk factors.

RESULTS

205 patients were included in the study, 149 (72.6%) had high embolic risk. 62 (30.2%) followed anticoagulation, 94 (45.8%) antiaggregation treatment, 5 (2.4%) both treatment and 49 (24%) were not receiving therapy. We didn't findings differences between age, sex, presence of ischemic heart disease, hypertension and congestive heart failure in last three months compared with the patients in respect to the group of patients with anticoagulation and antiaggregation therapy or without it. We determinate as well that previous stroke and echocardiographical finds (valve disease, valve calcification, ventricular dysfunction) were more frequent in the anticoagulation and antiaggregate patients than in those without therapy.

CONCLUSION

A high range of nonrheumatic AF patients take any kind of antithrombotic preventive therapy, though a great number of patients with high embolic risk could still get benefits from anticoagulation therapy. We should considerate in the therapy assessment some other clinical characteristics as hypertension, isquemic heart disease and heart failure apart from echocardiographical findings.

[Motor neuron disease and HIV]

Motor-neuron disease, in particular its commonest form (lateral amyotrophic sclerosis) is a degenerative disease of unknown aetiology and inexorable course with an estimated incidence of 0.4-1.8 per 100,000 inhabitants. In recent years great efforts have been made to discover the aetiopathogenesis of this disorder, studying genetic, viral, endocrine, toxic factors, etc. We present the case of a 30 year old man who started to develop a clinical condition compatible with motor-neuron disease 18 months after diagnosis of HIV. An extensive differential diagnosis was considered in view of this past history. Complementary tests considered necessary for diagnosis of motor-neurone disease and for exclusion of other neurological conditions related to HIV were done. After 16 months of follow-up the condition has become a clear case of ELA type motor neurone disease with no further HIV-related pathology. We discuss questions concerning the aetiopathology of the disease, based on the currently accepted viral hypothesis and describe recent findings related to both.

Changes in plasma concentrations of vasoactive neuropeptides in patients with sepsis and septic shock

The aim of this work was to study the hypothesis that the release of vasoactive neuropeptides may be related to the hemodynamic changes and severity of disease in human sepsis and septic shock. Twenty-two patients diagnosed with sepsis and treated in medical wards with standard supportive therapy and twenty patients admitted to a medical intensive care unit because of septic shock were studied Twenty healthy volunteers in a similar age range were enrolled as control group. Blood samples were taken at onset and every 12 hours on the following day after hospital admission to measure plasma concentrations of calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and substance P (SP). Clinical and biochemical variables were measured simultaneously. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was calculated on admission. From the day of admission, septic shock patients had significantly higher plasma CGRP-like immunoreactivity levels than patients with sepsis, as well as both groups of patients compared to control subjects. Plasma NPY-like immunoreactivity levels in patients with either sepsis or septic shock was significantly increased, and plasma SP-like immunoreactivity levels significantly reduced compared to those in controls. Plasma CGRP levels at study entry correlated with the APACHE II score (r = 0.71, p < 0.01), as well as with the cardiac index (r = 0.61, p < 0.05) and systemic vascular resistance index (r = -0.62, p < 0.05). Our data suggest that both CGRP and NPY, but not SP, are increasedly released into the circulation during the development of human sepsis and septic shock. In patients with sepsis the vasoconstriction mediated by the release of NPY appears to counterbalance the vasodilatory effect of CGRP. In septic shock patients, however, the release of NPY might be inadequately low to overcome the widespread CGRP-induced vasodilation.

[Treatment of chronic hepatitis C virus infection with interferon in patients infected with the human immunodeficiency virus]

FOUNDATION

We assessed the effectivity of the treatment with interferon (IFN) in patients infected by the human immunodeficiency virus (HIV) with chronic hepatitis (CH) by the hepatitis C virus (HCV).

METHODS

We studied 14 heterosexual males ex-parenterally drug consumers (PDC) and infected by the HIV (mean age 26 +/- 4.2 years), belonging to group A of CDC (1993); 10 had values of CD4 > 500 mmc and 4, between 200 and 500, the latter receiving treatment with zidovudine. In all these patients, the diagnosis of active chronic hepatitis was confirmed through histology. Three MUI of IFN-alpha 2b, 3 days/week during 24 weeks were administered. Sustained response to treatment was considered as the normalization of the aminotransferase levels until the end of the study; partial response, as the 50% decrease in the initial levels until the end of the treatment; relapse, as the response and latter increase in 1.5 of the ALT values at the end of the 24 weeks; and absence of response, as the lack of significant changes in the aminotransferase concentrations.

RESULTS

Tolerance of the treatment was good, without severe side effects and just in one case, the medication had to be interrupted. In 5 patients, there was a response (all of them with more than 500 CD4). In 2 of these patients, the response was partial. In 3, there was a relapse and 3 other patients did not show any response (CD4 > 500). Three patients gave up the treatment.

CONCLUSIONS

IFN-alpha 2b is well tolerated in a 24-week treatment in patients with HIV, CH and HCV. However, it was only effective for the control of this disease in patients with HIV infection with more than 500 lymphocytes CD4, without any significant effect in the evolution of the HIV infection.

Use of alkenylresorcinols from Ononis speciosa as synthetic precursors of compounds with potential biological activity

Selective ozonization of the alkenylresorcinols isolated from Ononis speciosa was studied. The derivatives thus obtained were used as precursors in the synthesis of cannabinoids and macrocyclic lactones.