Distinguishing melanocytic nevi from melanomas using static and dynamic infrared thermal imaging

BACKGROUND

The incidence rates of melanoma have risen to worrying levels over the last decade. Delayed diagnosis, due to faults on the detection stage, indicates the necessity of new aiding diagnosis techniques. Since metabolic activity is highly connected to neoplasia formation, a detection technique that focuses its results on vascular responses, as Infrared thermal (IRT), seems to be a viable option.

MATERIALS AND METHODS

Static and dynamic (cooling) thermal images of melanoma and melanocytic nevi lesions were collected and analysed to retrieve thermal parameters characteristic of this skin lesion types. The steady-state and dynamic variables were tested separately with different machine learning classifiers to verify whether the distinction of melanoma and nevi lesions was achievable.

RESULTS

The differentiation of both types of skin tumours was doable, achieving an accuracy of 84.2% and a sensitivity of 91.3% with the implementation of a learner based on support vector machines and an input vector composed by static variables.

CONCLUSION

The use of IRT for skin tumour classification is achievable, but some improvement is needed to raise the metrics of sensitivity and specificity. For future work, it is recommended the study of dynamic parameters for the classification of other types of skin neoplasia.

A simple equation to estimate the osmolarity of neonatal parenteral nutrition solutions

A predictive equation of osmolarity that correlates closely with the measured osmolality was determined. Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal parenteral nutrition solutions.

OBJECTIVE

We measured the osmolalities of neonatal parenteral nutrition (PN) solutions to determine if these values may be predicted by a simple equation for calculation of their osmolarity values.

METHODS

The osmolalities of 101 consecutive different final PN admixtures, prepared for 36 neonates, were measured by the freezing point depression method. The respective intra-assay and interassay coefficients of variation were always <2.1%. Linear multivariate regression analysis was used to determine a predictive equation of osmolarity that correlates closely with the value of measured osmolality.

RESULTS

The mean (SD) osmolality of the final PN admixtures was 749.7 (165.4) mOsm/kg. The best-fitted equation, with a coefficient of discrimination R2 = .95 (R2 = .90 for samples between 500 and 1000 mOsm/L) is osmolarity (mOsm/L) = (nitrogen x 0.8) + (glucose x 1.235) + (sodium x 2.25) + (phosphorus x 5.43)-50, with the concentration of components in mmol/L. Adapting the equation in our daily practice, using g/L for glucose and amino acids, mg/L for phosphorus, and mEq/L for sodium, the equation is osmolarity (mOsm/L) = (amino acid x 8) + (glucose x 7) + (sodium x 2) + (phosphorus x 0.2) - 50, with a similar R2.

CONCLUSIONS

Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal PN solutions, thus allowing more accurate decisions to be taken regarding the choice of route and rate of administration of PN solutions.

Sudden cadmium increases in the digestive gland of scallop, Nodipecten nodosus L., farmed in the tropics

Cadmium bioaccumulation in Nodipecten nodosus reared on a marine farm in a tropical bay was measured in muscle tissue and the digestive glands in animals ranging from 6 to 16 months. No bioaccumulation tendencies regarding Cd concentration were observed in muscle tissue (below 1 μg g⁻¹), while in the digestive gland concentrations remained below 5 μg g⁻¹ until the organisms reached 10 months, and reached levels above 10 μg g⁻¹ from 12 months onwards (reaching 27 μg g⁻¹). This is the same bioaccumulation pattern noted in animals transplanted to a different Cd exposure. Allometry and environmental factors cannot explain this sudden increase.

Epithelial-myoepithelial parotid carcinoma after kidney transplantation

The occurrence of a second malignant neoplasm (SMN) in patients who have been submitted to kidney transplantation is increasing and causes concern; parotid carcinoma is rarely reported after transplantation and may be related to long-term chemotherapy.Salivary gland carcinomas displaying exclusively myoepithelial differentiation-myoepithelial carcinomas (EMC) are rare, being less than 1% of all salivary gland tumours. EMC arises most commonly in the parotid gland and usually occurs in women. Their histopathologic features, immunohistochemical profile and clinical behaviour remain controversial.

[Pulmonary ventricle bypass operations]

Cavopulmonary connections have been extensively used in the palliation of complex forms of congenital heart disease requiring some form of right heart bypass. We examine the mid term outcomes of pulmonary ventricle bypass operations in a single institution and performed by the same surgical team.

POPULATION

Between March 1999 and April 2006, 62 patients underwent pulmonary ventricle bypass operations: bidirectional cavopulmonary anastomosis (Glenn procedure), total cavopulmonary connections (Fontan procedure) and one and a half ventricle correction in two cases. Age at operation averaged three years (range: 0.42-25 years) for the Glenn procedure and seven years (range: 3-14 years) for the Fontan procedure. There were 36 male patients (58%) and 26 female patients (42%). The most common indication for surgery was the single ventricle defect, present in 66% of patients. Associated lesions included: transposition of the great arteries in 16 patients (35.6%), bilateral superior vena cava in four patients (8.9%), situs ambigus in five patients (11%), situs inversus in another patient (2.2%), Ebstein disease in one patient (2.2) and coronary fistula in another patient (2.2%). Sub-aortic stenosis was present in one patient (2.2%). Palliative surgery was performed in all, but three patients (5%), before the Fontan procedure.

RESULTS

Thirty two patients underwent bidirectional cavopulmonary anastomosis and thirty patients underwent cavopulmonary connections, total or 2nd stage. Mean cardiopulmonary bypass times were 50.6+/-21.9 minutes for the Glenn procedure and 88.5+/-26.3 minutes for the Fontan procedure. There was no intra-operative mortality, but two patients (3.2% (died in the first month after surgery; one due to failure of the Glenn circuit and sepsis and the other due to a low cardiac output syndrome and multi-organ dysfunction. Mean ventilation time was 5.2+/-1.7 hours for the Glenn operation and 6.2+/-3.2 hours for the Fontan operation. The mean length of stay in ICU was 3.4+/-2.8 days for patients undergoing the Glenn operation and 4.6+/-3.1 days for patients undergoing the Fontan operation and the mean length of hospital stay was 10.6+/-5.8 days for the Glenn operation and 19.1+/-12.6 days for the Fontan operation respectively. The mean follow up time was 4+/-2.1 years (minimum 0 years and maximum seven years), most patients being in NYHA class I. Epicardiac pacemakers were implanted in three patients due to arrhythmias. Two re-operations (6.7%) were needed, both in the same patient, after the Fontan procedure, this patient eventually died a few years after surgery.

CONCLUSIONS

The immediate and mid term outcomes of pulmonary ventricle bypass operations can have excellent results. From our point of view there has been an improvement, namely in the use of the extracardiac conduit technique in the 2nd stage of the Fontan operation.

[Ross procedure: mid term results]

The Ross procedure has been used in children and young adults for aortic valve replacement and the correction of complex obstruction syndromes of the left ventricular outflow tract. We report the mid-term results of the Ross procedure in a single institution and performed by the same surgical team.

POPULATION

Between March 1999 and December 2005, 18 patients were operated on using the Ross procedure. The mean age at the time of surgery was 12 years, being 12 patients male (67%). The primary indication for surgery was isolated aortic valve disease, being the predominant abnormality in 58% of cases aortic regurgitation and in 42% left ventricular outflow tract obstruction. Associated lesions included sub-aortic membrane in 3 patients (16%), small VSD in 2 patients (11%), bicuspid aortic valve in 4 patients (22%) and severe left ventricular dysfunction and mitral valve regurgitation in 1 patient (6%). Ten of the 18 patients (56%) had been submitted to previous surgical procedures or percutaneous interventions.

RESULTS

Early post-operative mortality was not seen, but two patients (11%), had late deaths, one due to endocarditis, a year after the Ross procedure, and the other due to dilated cardiomiopathy and mitral regurgitation. The shortest time of follow-up is 6 months and the longest 72 months (median 38 months). Of the 16 survivors, 14 patients are in class I of the NYHA and 2 in class II, without significant residual lesions or need for re-intervention. The 12 patients with more than a year of follow up revealed normal coronary perfusion in all patients and no segmental wall motion abnormalities. Nevertheless, two of the 12 patients developed residual dynamic obstruction of LVOT and in three patients aortic regurgitation of a mild to moderate degree was evident. Significant gradients were not verified in the RVOT.

CONCLUSIONS

The Ross procedure, despite its complexity, can be undertaken with excellent immediate results. Aspects such as the dilation of the neo aortic root and homograft evolution can not be considered in a study of this nature, seeing that the mean follow up time does not exceed 5 years.

[Surgical management of atrio-ventricular septal defects: a single-institutional experience]

OBJECTIVES

Atrio-ventricular septal (AVSD) defects include a variable spectrum of congenital malformations with different forms of clinical presentation. We report the surgical results, from a single institution, with this type of congenital cardiac malformation. Patients with hypoplasia of one of the ventricles were excluded from this analysis.

POPULATION

Between November of 1998 and June of 2005, 49 patients with AVSD were operated on by the same team and in the same department. The average age was 37.3 months (medium 6 months) and 31 patients were female. In 38 patients (78%) an inter-ventricular communication was present (AVSD-complete) and of these, 26 were of the type A of Rastelli, being 13 of type B or C. The age for defect correction of the complete form was of 5.5 months, palliative surgery was not carried out on any of the patients. Associated lesions included: Down's syndrome in 22 patients (45%), patent arterial duct in 17 patients (35%), severe AV regurgitation in 4 patients (8%), tetralogy of Fallot in two (4%) and sub-aortic stenosis in one patient (2%). Pre-operatively 10 patients presented severe congestive heart failure and two were mechanically ventilated.

RESULTS

Complete biventricular correction was carried out in all patients. The average time on bypass (ECC) was 74.1+/-17.5 min. and time of aortic clamping was 52.0+/-12.9 min. The complete defects were corrected by the double patch technique, and in all patients the mitral cleft was closed, except in two with single papillary muscle. There was no intra-operative mortality, but hospital mortality was 8%(4 patients), due to pulmonary hypertension crises, in the first 15 post-operative days. The mean ventilation time was of 36.5+/-93 hours (medium 7 h) and the average ICU stay was of 4.3+/-4.8 days (medium 3 days). The minimum follow-up period is 1 month and the maximum is 84 months (medium 29.5 months), during which time 4 re-operations (8%) took place: two for residual VSD's and two for mitral regurgitation. There was no mortality at re-do surgery. At follow up there was residual mitral regurgitation, mild in 17 patients and moderate in two. Four other patients presented with minor residual defects.

CONCLUSIONS

The complete correction of AVSD can be carried out with acceptable results, in a varied spectrum of anatomic forms and of clinical severity. Despite the age of correction, for the complete forms, predominantly below 12 months, pulmonary hypertension was the constant cause for post operative mortality. Earlier timing of surgery and stricter peri-operative control might still improve results.