Lipid profile of cerebrospinal fluid in multiple sclerosis patients: a potential tool for diagnosis.

Multiple sclerosis (MS) is a complex multifactorial neuropathology. Although its etiology remains unclear, it has been demonstrated that the immune system attacks myelin, leading to demyelination and axonal damage. The involvement of lipids as one of the main components of myelin sheaths in MS and other demyelinating diseases has been postulated. However, it is still a matter of debate whether specific alteration patterns exist over the disease course. Here, using a lipidomic approach, we demonstrated that, at the time of diagnosis, the cerebrospinal fluid of MS patients presented differences in 155 lipid species, 47 of which were identified. An initial hierarchical clusterization was used to classify MS patients based on the presence of 25 lipids. When a supervised method was applied in order to refine this classification, a lipidomic signature was obtained. This signature was composed of 15 molecules belonging to five different lipid families including fatty acids (FAs). An FA-targeted approach revealed differences in two members of this family: 18:3n3 and 20:0 (arachidic acid). These results reveal a CSF lipidomic signature in MS patients at the time of diagnosis that might be considered as a potential diagnostic tool.

Utilización de iones de plata incorporados en nanopartículas de arcilla para controlar la contaminación de superficies en el entorno del paciente / No disponible

Una de las causas origen de infecciones nosocomiales se encuentra en la contaminación del entorno del paciente. Los picaportes de las puertas o los carros de curas se encuentran libres de gérmenes muy poco tiempo tras su limpieza. (Carling, ICHE 2008) En el Hospital Nisa 9 de Octubre de Valencia Se ha llevado a cabo un estudio a doble ciego del efecto en la contaminación de las superficies mediante la aplicación de BactiBlock(R) 660 AO Antimicrobial Metal Coating, con tecnología basada en iones de plata incorporados en nanopartículas de arcilla. El estudio se efectuó sobre pomos de las puertas de habitaciones y sobre las asas y bandejas de los carros de curas, elegidos aleatoriamente. Los resultados demuestran que una única aplicación de Bactiblock(R) 660 AO Antimicrobial Metal Coating mantiene las superficies tratadas en un estado aséptico óptimo, después de un mínimo de 8 semanas

One of the causes of nosocomial infections origin is in the patient’s environment pollution. The doorknobs or the cures cars are free of germs very short time after cleaning. (Carling, ICHE 2008) At the Nisa 9 de Octubre Hospital of Valencia, it has conducted a double-blind study of the effect on the contamination of surfaces by applying BactiBlock(R) 660 AO Antimicrobial Metal Coating, with technology based on silver ions embedded in nanoparticles of clay. The study was conducted on doorknobs room and on the handles and tray cures cars, chosen randomly. The results show that a single application of Bactiblock(R) 660 AO Antimicrobial Metal Coating maintains the treated surfaces in optimum aseptic state after at least 8 weeks

Hypotrichosis associated with capillary malformation-arteriovenous malformation syndrome.

BACKGROUND: Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is associated with multifocal small CMs and a high risk for high-flow lesions. It is an autosomal dominant disorder, caused by RASA1 gene mutations. Recently, two novel clinical features have been identified: numerous small pale halos with central punctate red spots, and naevus anemicus. OBJECTIVES: To identify the prevalence of the new clinical manifestations in our patients with CM-AVM. The secondary objective was to investigate the presence of other skin lesions. METHODS: We retrospectively searched the picture database of our department for cases with a clinical diagnosis of CM-AVM, based on the identification of multiple cutaneous CMs and a negative history of epistaxis. We prospectively conducted a clinical and dermoscopic skin examination in all of these patients. RESULTS: Seven patients with multiple CMs were found, and only in one case was a cutaneous AVM present. Five patients had red punctate spots surrounded by pale halos on the upper limbs. Two adult patients also showed multiple telangiectasias on the neck and upper trunk. Naevus anemicus was not detected in any patient. A partial or total absence of vellous hair on the surface of CMs was observed in all patients. CONCLUSIONS: Red punctate spots with pale halos or small telangiectasias are frequent findings in CM-AVM syndrome. Hypotrichosis on the CMs suggests that RASA1 gene mutations could be involved in the hair follicle proliferation and cell cycle.

Solar radiation and water vapor pressure to forecast chickenpox epidemics.

The clear seasonality of varicella infections in temperate regions suggests the influence of meteorologic conditions. However, there are very few data on this association. The aim of this study was to determine the seasonal pattern of varicella infections on the Mediterranean island of Mallorca (Spain), and its association with meteorologic conditions and schooling. Data on the number of cases of varicella were obtained from the Network of Epidemiologic Surveillance, which is composed of primary care physicians who notify varicella cases on a compulsory basis. From 1995 to 2012, varicella cases were correlated to temperature, humidity, rainfall, water vapor pressure, atmospheric pressure, wind speed, and solar radiation using regression and time-series models. The influence of schooling was also analyzed. A total of 68,379 cases of varicella were notified during the study period. Cases occurred all year round, with a peak incidence in June. Varicella cases increased with the decrease in water vapor pressure and/or the increase of solar radiation, 3 and 4 weeks prior to reporting, respectively. An inverse association was also observed between varicella cases and school holidays. Using these variables, the best fitting autoregressive moving average with exogenous variables (ARMAX) model could predict 95 % of varicella cases. In conclusion, varicella in our region had a clear seasonality, which was mainly determined by solar radiation and water vapor pressure.

Can meteorological factors forecast asthma exacerbation in a paediatric population?

BACKGROUND: Asthma exacerbations attended in emergency departments show a marked seasonality in the paediatric age. This seasonal pattern can change from one population to another and the factors involved are poorly understood. OBJECTIVES: To evaluate the association between meteorological factors and schooling with asthma exacerbations in children attended in the paediatric emergency department of a district hospital. METHODS: We conducted a retrospective review of the medical records of children 5-14 years of age attended for asthma exacerbations during a 4-year period (2007-2011). Climatic data were obtained from a weather station located very close to the population studied. The number of asthma exacerbations was correlated to temperature, barometric pressure, relative humidity, rainfall, wind speed, wind distance, solar radiation, water vapour pressure and schooling, using regression analyses. RESULTS: During the study period, 371 children were attended for asthma exacerbations; median age was eight years (IQR: 6-11), and 59% were males. Asthma exacerbations showed a bimodal pattern with peaks in spring and summer. Maximum annual peak occurred in week 39, within 15 days from school beginning after the summer holidays. A regression model with mean temperature, water vapour pressure, relative humidity, maximum wind speed and schooling could explain 98.4% (p<0.001) of monthly asthma exacerbations. CONCLUSIONS: The combination of meteorological factors and schooling could predict asthma exacerbations in children attended in a paediatric emergency department.

Similar biological effect of high-dose oral versus intravenous methylprednisolone in multiple sclerosis relapses.

UNLABELLED: Our aim was to investigate differences in immune mechanisms in multiple sclerosis (MS) relapse, after high-dose oral methylprednisolone (oMP) or intravenous methylprednisolone (ivMP). We measured serum cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, TNF-α and IFN-γ) in 39 of 49 MS patients with moderate-severe relapse, whom were treated with ivMP or oMP in a placebo-controlled, non-inferiority clinical trial. We assessed these cytokine levels at baseline and at 1 and 4 weeks post-treatment. The cytokine levels between oMP and ivMP were similar at any time. Proinflammatory cytokines (IL-6 and IFN-γ) were significantly decreased in both groups at week 1 (p = 0.05 / p = 0.03) and at week 4 (p = 0.04 / p = 0.05). This study provides further confirmatory evidence that oMP is not inferior to ivMP. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT00753792.

Are hospitalizations for rotavirus gastroenteritis associated with meteorologic factors?

Local climatic factors might explain seasonal patterns of rotavirus infections, but few models have been proposed to determine the effects of weather conditions on rotavirus activity. Here, we study the association of meteorologic factors with rotavirus activity, as determined by the number of children hospitalized for rotavirus gastroenteritis on the Mediterranean island of Mallorca (Spain). We conducted a retrospective review of the medical records of children aged 0-5 years admitted for rotavirus gastroenteritis between January 2000 and December 2010. The number of rotavirus hospitalizations was correlated to temperature, humidity, rainfall, atmospheric pressure, water vapor pressure, wind speed, and solar radiation using regression and time-series techniques. A total of 311 patients were hospitalized for rotavirus gastroenteritis in the 11-year study period, with a seasonal pattern from December to June, and a peak incidence in February. After multiple regressions, weekly rotavirus activity could be explained in 82 % of cases (p < 0.001) with a one-week lag meteorologic model. Rotavirus activity was negatively associated to temperature and positively associated to atmospheric pressure, solar radiation, and wind speed. Temperature and solar radiation were the factors that contributed most to the model, with a peak rotavirus activity at 9 °C and 800 10KJ/m(2), respectively. In conclusion, hospitalization for rotavirus was strongly associated with mean temperature, but an association of rotavirus activity with solar radiation, atmospheric pressure, and wind speed was also demonstrated. This model predicted more than 80 % of rotavirus hospitalizations.

Varicela hemorrágica asociada a síndrome de distrés respiratorio agudo / Hemorrhagic chickenpox associated to acute respiratory stress syndrome

Niño de 5 años de edad que ingresa en la UCI por insuficiencia respiratoria severa con el antecedente de una varicela clínica de 10 días de evolución. El paciente presenta un mal estado general, palidez cutánea cérea generalizada, mala perfusión periférica y piel fría. Se observaron abundantes lesiones cutáneas vesiculosas hemorrágicas generalizadas. En la radiografía de tórax se observó condensación algodonosa del parénquima bilateral compatible con síndrome de distrés respiratorio agudo (SDRA) y probable neumotoráx derecho basal con derrame pleura. Los resultados microbiológicos fueron negativos salvo el aislamiento de virus varicela-zoster en el exudado de las lesiones cutáneas. Asimismo, la técnica de amplificación genómica (PCR) fue positiva para varicela zóster en el aspirado traqueal y el derrame pleural. Al tercer día de su ingreso el paciente presentó un episodio brusco de hipotensión arterial, con sangrado activo por fosas nasales y boca y fallecimiento (AU)

Children of 5 years old who is admitted to the ICU for severe respiratory failure with a history of clinical varicella with 10 days of evolution. The patient presented with malaise, generalized waxy pallor, poor peripheral perfusion and cold skin. There were plenty of vesicular skin lesions generalized bleeding. The chest radiograph showed bilateral condensation cottony parenchyma compatible with acute respiratory distress syndrome (ARDS) and right pneumothorax with basal pleural effusion. The microbiological results were negative except the isolation of varicella-zoster virus in the exudate of the skin lesions. Like wise, the genomic amplification technique (PCR) was positive for varicella-zoster virus in tracheal aspirate and pleural effusion. On the third day of admission the patient presented a sudden episode of hypotension, with active bleeding from nose and mouth and died (AU)

Specific IgE levels to Dermatophagoides pteronyssinus are associated with meteorological factors.

BACKGROUND: Dermatophagoides pteronyssinus specific IgE (sIgE) measurement is a major diagnostic test for the detection of sensitization to that allergen. METHODS: To investigate the effect of climate on the seasonal variations of D.pteronyssinus sIgE, we studied the tests performed in an insular population during a 10-year period. The association with meteorological factors was evaluated with multiple regression analyses. RESULTS: Of 24,879 tests performed for D. pteronyssinus sIgE, 16,719 (67.2%) were D. pteronyssinus sIgE positive; 24.5% were tested for asthma and 46.07% for rhinitis. D. pteronyssinus sIgE levels showed a seasonal pattern with an annual peak in November. In the multivariate analyses solar radiation (r = -0.94) and relative humidity (r = 0.86) were independent factors associated with D. pteronyssinus sIgE levels. The resulting model could explain 93% (p < 0.001) of D. pteronyssinus sIgE variability. CONCLUSIONS: Our population showed a seasonal pattern of D. pteronyssinus sIgE explained by relative humidity and solar radiation.

Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: development of a control strategy for efficiency enhancement.

The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H(2)O(2) has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system - a proportional and integral controller (PI) with an anti-windup mechanism - has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency.

Epidemiology of hospitalization for acute bronchiolitis in children: differences between RSV and non-RSV bronchiolitis.

We study the clinical, management and outcome differences between respiratory syncytial virus (RSV) positive and negative bronchiolitis. A retrospective review of the medical records of children ≤ 2 years of age with acute bronchiolitis between January 1995 and December 2006 was done. There were 2,384 patients hospitalized for acute bronchiolitis, and 1,495 (62.7%) were RSV infections. Overall, hospitalization rate was 55/1,000 admissions. Mortality occurred in 0.08% of cases. Bronchiolitis due to RSV was more frequent from November to March (97%). RSV bronchiolitis had longer hospital stays (6 vs. 5 days, P<0.0001), higher risk of intensive care unit (ICU) admission (OR 2.7; 95%CI 1.87-3.9) and more oxygen use (OR 2.2; 95%CI 1.8-2.6). Infants < 2 months had longer median hospital stay (6 vs. 5 days, P <0.0001) and higher risk of ICU admission (OR 3.4; 95%CI 2.5-4.6). Prematures of < 32 gestational weeks, congenital heart disease, and atelectasis/condensation were the main risk factors for ICU admission in both RSV and non-RSV bronchiolitis. The introduction of palivizumab in prematures diminished hospitalization for RSV bronchiolitis, oxygen need, length of hospital stay and mechanical ventilation. In conclusion, this study supports that RSV bronchiolitis seems to be a more severe disease than that caused by other viruses.

How frequent is varicella-associated pneumonia in children?

Varicella is a frequent though mild infection in children, but it can cause important morbidity in adults. The most frequent complication in adults is varicella pneumonia. However, lower airway complications associated to varicella have been scarcely studied in children. We retrospectively reviewed the clinical records of the children hospitalized for varicella-associated pneumonia in the three public hospitals on the Island of Mallorca. We discovered that 17/213 (8%) children hospitalized for varicella were diagnosed of pneumonia. The rate of hospitalization for varicella complication due to pneumonia was 4.3 cases per 10,000 varicella infections. Only one patient was diagnosed of varicella pneumonia, which accounts for 0.3 cases per 10,000 varicella infections. Nine of 17 (53%) cases were classified as bacterial pneumonia. Statistical differences (p < 0.05) in the median time from rash (5.9 vs. 2.4 days) and fever (4.1 vs. 2.2 days) to admission were observed between bacterial and viral pneumonia. However, outcome differences measured by the median length of stay, need for oxygen, and admission to the intensive care unit were not observed. Varicella pneumonia is a very rare complication of varicella in children. Most of the lower airway infections in the course of varicella are associated to other co-infections.

Metástasis hipofisiaria de un adenocarcinoma de endometrio: a propósito de un caso / Pituitary metastases from an endometrial adenocarcinoma: A propos of a case viernes, 03 sep 2010

Los tumores metastásicos de la glándula hipofisiaria procedentes de adenocarcinoma de endometrio son excepcionales. Se presenta el caso de una mujer de 59 años que dos años después de ser diagnosticada y tratada de un adenocarcinoma de endometrio comienza con una hemianopsia bitemporal, a raíz de la cual se le diagnostica una metástasis hipofisiaria. Se realiza una revisión de la clínica, el diagnóstico y el tratamiento de los pacientes con metástasis hipofisiarias (AU)

Metastatic tumors of the pituitary gland from an endometrial adenocarcinoma are extremely rare. We report the case of a 59-year-old woman who, 2 years after diagnosis and treatment of an endometrial adenocarcinoma, developed bitemporal hemianopsia. Pituitary metastasis was found. The clinical presentation, diagnosis and therapeutic management of patients with pituitary metastases are reviewed (AU)

Sudden death associated with Clostridium sordellii in captive lions (Panthera leo).

In the spring of 2003, a series of sudden deaths in a group of adult lions (Panthera leo) with a previous history of depression, inanition, and lethargy, was investigated. Five animals died within 24 to 36 hours after onset of signs of disease. Serologic screening for viral disease detection was negative, evidence of parasites was not detected, and results of a complete blood count and serum biochemical analysis were within reference intervals in all lions. The most relevant lesions observed were multiple areas of necrosis and hemorrhage in the intestinal outer muscular layer, and cellulitis with an intense bloody edema in the mesenteric and the pericardial fat tissue. On the basis of the fulminant course of the disease, the gross and histologic findings, and the isolation and identification of Clostridium sordellii, a diagnosis of infectious myositis and cellulitis associated with acute clostridiosis was made. To the authors' knowledge, this is the first report of sudden death associated with C. sordellii in felines.

[Acute obstructive renal failure secondary to retroperitoneal mass]. / Fracaso renal agudo obstructivo por masa retroperitoneal.

The acute renal failure is a grave pathology, of rapid establishment and relatively frequent in the hospital environment. We can describe three etiological groupS, which are responsible for it, amongst which are emphasized the pre-renal reasons. The obstructive pathology, of minor incidence, increases with the age. It is described the case of a 67-yr-old patient who was admitted in the Nephrology Service because of abrupt decline of the renal function. Among the initial symptoms, he presented arterial hypertension (190/90) and preserved diuresis. Blood analysis: urea 199 mg/dl, creatinine 7.7 mg/dl, without proteinuria. Sonography reported a bilateral ureteral hydronephrosis with simple cyst of possible ischemic origin. In view of the absence of previous biochemical data of renal failure, we considered possible reasons which start with an acute pattern. In initial evaluation, pre-renal etiology was not seen (high blood pressure, right cardiac systole function). The absence of prostatic syndrome and sonography discovery did not justify a diagnosis of urinary tract obstruction. Finally, abdominal-pelvic scan showed a periaortic retroperitoneal mass which included both ureters and appeared to trigger the obstruction. Combined efforts were pursued with the Urology Service, which implanted a bilateral "double J" catheter and later operated surgically on the patient, carrying out an alternating ureterolysis of both ureters. The biopsy manifested a retroperitoneal fibrosis, and the renogram showed a residual renal function of 20% in the right kidney and 80% in the left kidney. Due to the failure of the previous measures and as a last therapeutic recourse when one year had passed from the diagnosis, a continuous regimen with tamoxifen (anti-estrogen drug) in dose of 20 mg/dl each 12 hours was started, which began a progressive remission in the size of the observed mass by scan (CT) and magnetic resonance (MR). The treatment was completed during 12 months and in this time, the levels of blood urea nitrogen and creatinine were reduced gradually too. Finally, at the end of the treatment, the magnetic resonance demonstrate the complete disappearance of the fibrosis.

Fracaso renal agudo obstructivo por masa retroperitoneal / Acute obstructive renal failure secondarty to retroperitoneal mass

El fracaso renal agudo es un proceso grave, de instauración rápida y relativamente frecuente en el medio hospitalario. Clásicamente se describen tres grupos etiológicos responsables del mismo, entre los cuales destacan las causas prerrenales. La patología obstructiva, de menor incidencia, aumenta con la edad. Se describe el caso de un paciente de 67 años que ingresa en el Servicio de Nefrología por un deterioro brusco de la función renal. Entre los síntomas iniciales, presenta hipertensión arterial (190/90) y diuresis conservada. La analítica pone de manifiesto una urea de 199 mg/dl, con creatinina de 7,7 mg/dl, sin proteinuria. La ecografía informa una hidronefrosis renoureteral bilateral con quistes simples de posible origen isquémico. Dada la ausencia de datos bioquímicos previos de insuficiencia renal, se consideran posibles causas desencadenantes del cuadro agudo. En la valoración inicial, la etiología prerrenal no tienen fundamento clínico (tensión arterial elevada, correcta función sistólica cardíaca por ecocardiografía), ni bioquímico. La ausencia de síndrome prostático y los hallazgos ecográficos tampoco justifican una obstrucción del tracto urinario. Por último, la tomografía abdomino-pélvica evidencia una masa retroperitoneal periaórtica que engloba ambos uréteres y parece desencadenante del cuadro obstructivo. Se inicia un seguimiento conjunto con el Servicio de Urología, que implanta unos catéteres «doble J» bilaterales y más adelante, interviene quirúrgicamente al paciente llevando a efecto una ureterolisis alterna de ambos uréteres. El material de biopsia informa de fibrosis retroperitoneal, y el renograma evalúa una función renal residual del 20% en riñón derecho y del 80% en el izquierdo. Ante el fracaso de las medidas quirúrgicas anteriores y como último recurso terapéutico, se ensaya al año del diagnóstico, una pauta continua con tamoxifeno (antiestrógeno) a dosis de 20 mg/dl cada 12 horas, que inicia una remisión progresiva en el tamaño de la masa, objetivada por tomografía (TAC) y resonancia magnética (RMN). La pauta se completa durante 12 meses y en este tiempo se reducen también de forma paulatina, los niveles de nitrógeno uréico y creatinina en sangre. Finalmente al término del tratamiento, la RMN evidencia la desaparición total de la fibrosis (AU)

The acute renal failure is a grave pathology, of rapid establishment and relatively frecuent in the hospital environment. We can describe three etiological group, which are responsible of himself, amongst which are emphasized the pre-renal reasons. The obstructive pathology, of minor incidence, increase with the age. It in described the case of a patient with 67 years old who is admitted in the Nephrology Service because of abrupt spoiling of the renal function. Between initials symptons, he presents arterial hipertension (190/90) and preserved diuresis. The analytics manifest: urea 199 mg/dl, creatinine 7.7 mg/dl, without proteinuria. Sonography reports a bilateral ureteral hydronephrosis with simple cyst of possible ischemia origin. In view of the absence of previus biochemicals data of renal failure, it is considered possibles reasons which start acute pattern. In initial evaluation, pre-renal etiology has not clinical basis (high blood pressure, right cardiac systole function). The absence of prostatic syndrome and sonography discovery, neither justify an urinary tract obstruction. Finally, abdominal-pelvic scan show a periaortic retroperitoneal mass which include both ureter and appear like outbreak ob obstruent patern. It is begun a combined pursuit with the Urology Service, which implant a bilateral «double J» catheter and later, operate on surgicaly the patient, carrying out an alternating ureterolysis of both ureter. The equipment of byopsy manifested a retroperitoneal fibrosis, and the renogram evaluate a residual renal function of 20% inside right kidney and 80% inside left kidney. Before the failure of the previous measuring and like last therapeutic recourse, it is tried when one year has passed from the diagnostic, a continuous guide with tamoxifen (anti-estrogen drug) in dose of 20 mg/dl each 12 hours, which begins a progressive remission in the size of the objectified mass by scan (CT) and magnetic resonance (MR). The guide is completed during 12 months and in this time, the levels of ureic nitrogen and creatinine in blood, are reduced gradually too. Finally, at the end of the treatment, the magnetic resonance demonstrate the complete disappearance of the fibrosis (AU)

African swine fever and classical swine fever: a review of the pathogenesis.

This paper describes major pathogenetic mechanisms of African and Classical Swine Fever virus infections. The interactions between both viruses and the monocyte-macrophage-system result in the release of mediator molecules, which are important for the further progression of the diseases. The causes of the thrombocytopenia and the mechanisms of the haemorrhages, which are characteristic in both infections, are described. Apoptotic cell death is regarded as the predominant cause of lymphopenia in both virus infections.

Growth marks observation: preferential techniques and teeth for ageing of Spanish red deer (Cervus elaphus hispanicus).

A total of 207 teeth belonging to 53 deer (Cervus elaphus hispanicus) from Sierra Morena (South of Spain) were analysed using histological thin sections and/or polished thick sections. Growth marks were observed in dentine and cementum of incisors, molars and canines. Tooth, region of the tooth, and type of preparation giving the best performance in terms of sharpness and interpretation ease of the growth marks, when used for Spanish deer ageing, were identified. The tissue chosen for the study was the cellular cementum of the inter-radicular pad from molars and the acellular cementum of the root from incisors, both observed through longitudinal cuts. Histological sections obtained with a conventional microtome were optimal for a reliable identification of the first growth marks. In sections thicker than 15 microm the first rest line, when observed in cementum can be confused with the cementum-dentine junction; whereas in the polished sections from molars it will not appear at all. Dentine interpretation was more difficult. Its observation should only be accomplished using cross-sections of the molar root. Secondary or accessory marks were visible in every tooth, being those from the molar pad the easiest to distinguish. Canines were the less suitable teeth for this study.