Proteína precursora del beta-amiloide (ß-App) y daño axonal difuso tras un traumatismo craneoencefálico: un punto de vista forense / Beta-amiloid precursos protein (ß-App) and diffuse axonal damage after head injuries: a forensic point of view

Resumen La proteína precursora del β- Amiloide (β-APP) es una glicoproteína de membrana y un componente habitual de las neuronas. Tiene funciones en el crecimiento y la adhesión celular tras un traumatismo. Es transportada mediante transporte rápido axonal anterógrado y se acumula dentro de las neuronas cuando se daña citoesqueleto. Este proceso es activo, es decir consume energía. El β-APP no es específico de los traumatismos. Se acumula en cualquier circunstancia en la que se dañen los axones, tal como la hipoxia, alteraciones metabólicas, y cualquier otra causa de edema cerebral y aumento de la presión intracraneal que puedan conducir a un daño axonal difuso (DAI) En el presente estudio estudiamos la expresión de esta proteína en casos de traumatismo cráneo-encefálico con diferente evolución cronológica El daño del citoesqueleto producido por la proteólisis, junto con la alteración de las quinasas y las fosfatasas, aumentan la permeabilidad de la membrana, lo que provoca la entrada de calcio en la célula que, a su vez, activa la calmodulina que hace que los neurofilamentos se compacten, los microtúbulos desaparezcan y se rompa la espectrina. Esta disrupción del citoesqueleto tiene como consecuencia que las sustancias que se transportan a su través, se acumulen, sobre todo en las zonas afectadas por el DAI. Al final de todo este proceso, los axones se rompen, lo que se conoce como axotomía secundaria. El estudio de la acumulación del β-APP es útil para valorar la extensión del DAI y para determinar el tiempo de supervivencia tras el traumatismo o cualquier otro daño cerebral.

Abstract β-Amyloid Precursor Protein (β-APP) is a membrane glycoprotein and a common component of neurons. It is involved in adhesion and cell growth processes after traumatic events. It is carried by anterograde fast axonal transport, and it accumulates inside neurons when the cytoskeleton is damaged. This is a vital biochemical process that consumes energy. β-APP is not specific of traumatic events. It accumulates in any case of axonal damage, whatever its cause may be, like hypoxia, metabolic disorders, and any other circumstances that lead to brain swelling and intracranial pressure rising and in consequence to Diffuse Axonal Injury (DAI). In this study we review the expression of this protein in cases of traumatic brain injury with different chronological evolution. The damage of cytoskeleton due to proteolysis in addition to the disturbance of kinases and phosphatases increase the permeability of the membrane. Calcium gets into the cell and activates calmodulin, thus neurofilaments compact, microtubules disappear and spectrin breaks. This disruption of the cytoskeleton has as consequence that the transported substances accumulate in the most affected areas by DAI. At the end of this process axon breaks, which is known as secondary axotomy. The study of the accumulation of β-APP is useful to assess the extent of DAI and to determine the time elapsed after trauma or another insult to CNS.

Case report of segmental odontomaxillary dysplasia with cutaneous manifestations.

BACKGROUND: Segmental odontomaxillary dysplasia is an uncommon nonhereditary growth disorder that affects the maxilla, gums and ipsilateral dentition. The disorder is diagnosed mainly based on dental (over-retention of primary teeth, dental agenesis and diastemas) and bone findings (bone sclerosis, irregular trabeculation of immature bone and reduced maxillary sinus). This paper provides a case report. CASE REPORT: A 5-year-old child with skin manifestations including hypertrichosis, facial erythema and pigmented nevus was diagnosed with type II segmental odontomaxillary dysplasia based on clinical, radiographic and histopathological analysis. CONCLUSION: The skin findings can help with the suspicion of segmental odontomaxillary dysplasia, although the definitive diagnosis is typically established by a paediatric dentist based on clinical and radiological findings.

Oral mucosal peeling related to dentifrices and mouthwashes: A systematic review.

BACKGROUND: The aim of this systematic review was to summarise the clinical information available about oral mucosal peeling (OMP) and to explore its aetiopathogenic association with dentifrices and mouthwashes. MATERIAL AND METHODS: PICOS outline. Population, subjects diagnosed clinically and/or pathologically. Intervention, exposition to oral hygiene products. Comparisons, patients using products at different concentrations. Outcomes, clinicopathological outcomes (primary) and oral epithelial desquamation (secondary) after use. Study design, any. Exclusion criteria, reports on secondary or unpublished data, in vitro studies. Data were independently extracted by two reviewers. RESULTS: Fifteen reports were selected from 410 identified. Descriptive studies mainly showed low bias risk, experimental studies mostly an "unclear risk". Dentifrices or mouthwashes were linked to OMP, with an unknown origin in 5 subjects. Sodium lauryl-sulphate (SLS) was behind this disorder in 21 subjects, tartar-control dentifrices in 2, and flavouring agents in 1 case. Desquamation extension was linked to SLS concentration. Most cases were painless, leaving normal mucosa after desquamation. Tartar-control dentifrices caused ulcerations more frequently. CONCLUSIONS: OMP management should consider differential diagnosis with oral desquamative lesions, particularly desquamative gingivitis, with a guided clinical interview together with pathological confirmation while discouraging the use of the product responsible for OMP.

A Dramatic Case of Odynophagia.

We report the case of a 77-year-old male with a history of aortic stenosis and interstitial lung disease, who debuted 3 years ago with an outbreak of necrotic and very painful canker sores. The severity of the lesions and their refractory response to treatment led to several hospital admissions and multiple consultations to different specialists (ENT, rheumatology, dermatology, ophthalmology, cardiology, and internal medicine). During this time, the patient received central parenteral nutrition with an episode of catheter-related septicemia, and he came to require psychiatric assistance for autolytic ideation. Numerous diagnostic tests were performed with inconclusive results, including biopsy of the lesion (histological study, immunohistochemistry for CD68 + , CD4 + , CD8 + , CD20 + , MCT +, and cytomegalovirus, PAS, Grocott-Gomori and Zielh-Neelsen staining, and in situ hybridization for Epstein Barr virus). Numerous treatments were unsuccessfully tested until thalidomide was administered, thus completely remitting lesions but leaving retractable scarring sequelae. Since then, the patient has had two recurrences, coinciding with the reduction of thalidomide dosages, which were controlled by increasing the dose of the immunomodulator. Recurrent necrotizing major aphthous stomatitis (Sutton's disease) is a clinical variant of recurrent aphthous stomatitis that may have a dramatic course. Unfortunately, the lack of etiopathogenetic uniformity precludes any specific treatment. In severe cases, immunomodulators, including thalidomide, may represent a valid therapeutic option.

Subcutaneous emphysema related to air-powder tooth polishing: a report of three cases.

Subcutaneous emphysema is a rare complication of dental procedures and can occasionally give rise to potentially life-threatening complications. We describe three cases of subcutaneous emphysema diagnosed in the same dental clinic. All cases occurred during tooth or implant cleaning using air polishing (KavoProphyflex® ) with a sodium bicarbonate powder (Air-N-Go Classic® ). The diagnosis was based on clinical findings and was confirmed radiologically. The cervical and facial regions were affected in all three cases, and spread to the mediastinum occurred in one case. All the episodes resolved within 3-5 days. Tooth cleaning using air polishing combined with an abrasive powder is a risk factor for subcutaneous emphysema, especially when the powder and device are from different manufacturers. Radiological assessment must be performed to rule out involvement of deep tissue planes.

Er,Cr:YSGG laser therapy for oral leukoplakia minimizes thermal artifacts on surgical margins: a pilot study.

Laser use for biopsy of suspicious lesions may simulate cytological atypia at the margin of the incisions, challenging pathological diagnosis. Erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser has shown promising results in experimental models by inducing fewer artifacts. The aims of this study were to examine the thermal wounds induced by Er,Cr:YSGG laser in a short series of oral leukoplakias in terms of cytological and epithelial architectural changes and also to assess the width of the thermal damage lateral to the incision. Four oral leukoplakia patients entered the study and underwent complete surgical excision of their lesions by using Er,Cr:YSGG laser. Patients were weekly controlled until complete healing was accomplished. The patients were included on the existing follow-up program for these lesions thereafter. Study samples were routinely processed by the same technician and double-blindedly studied by two pathologists until a consensus was reached for each case. The pathological analysis of the samples revealed no autolysis and no fixation- or handling-related artifacts. However, cellular and nuclear polymorphism could be observed in two samples. Loss of intercellular adherence was the most frequent thermal artifact in this series; all pseudodysplastic artifacts recognized in the study were of low intensity and located at the basal and suprabasal layers of the leukoplakias' epithelium. The width of the thermal damage at the edge of the incision scored an average of 26.60 ± 25.3 µm. It is concluded that irradiation with Er,Cr:YSGG laser induces a minimal amount of thermal artifacts at the surgical margins of oral leukoplakias and avoids diagnostic interferences with real dysplastic borders.

Er,CR:YSGG lasers induce fewer dysplastic-like epithelial artefacts than CO2 lasers: an in vivo experimental study on oral mucosa.

Our aim was to assess wounds made by lasers (CO(2) and Er,Cr:YSGG) for their epithelial architectural changes and width of damage. We allocated 60 Sprague-Dawley(®) rats into groups: glossectomy by CO(2) laser at 3 different wattages (n=10 in each); glossectomy by Er,Cr:YSGG laser at two different emissions (n=10 in each), and a control group (n=10). Histological examination assessed both prevalence and site of thermal artefacts for each group. Both lasers (CO(2) and Er,Cr:YSGG) caused the same type of cytological artefacts. The 3W Er,Cr:YSGG laser produced the fewest cytological artefacts/specimen, and was significantly different from the other experimental groups: 3W CO(2) laser (95% CI=0.8 to 1.0); the 6W CO(2) laser (95% CI=0.1 to 2.0) and the 10W CO(2) laser (95% CI=1.1 to 3.0). CO(2) lasers (3-10W) generate epithelial damage that can simulate dysplastic changes with cytological atypia that affects mainly the basal and suprabasal layers. Irradiation with Er,CR:YSGG laser (2-4W) produces significantly fewer cellular artefacts and less epithelial damage, which may be potentially useful for biopsy of oral mucosa.

Substantivity of a single chlorhexidine mouthwash on salivary flora: influence of intrinsic and extrinsic factors.

OBJECTIVES: To analyse the influence of intrinsic and extrinsic factors on the in vivo antimicrobial activity of a chlorhexidine (CHX) digluconate mouthwash on the salivary flora up to 7h after its application, using epifluorescence microscopy. METHODS: Ten volunteers performed the following mouthwashes: 0.12% CHX (10ml/30s, 15ml/30s and 10ml/1min); 0.2% CHX (10ml/30s, 15ml/30s and 10ml/1min); 0.2% CHX (10ml/30s) plus different daily activities (eating, drinking, chewing or smoking). RESULTS: On comparing 0.12% CHX (10ml versus 15ml), the greatest differences in bacterial viability were detected at 1h and 3h. On comparing 0.12% CHX (30s versus 1min) the greatest differences in viability were detected at 1h, 3h, and 5h; and with 0.2% CHX (30s versus 1min), at 5h and 7h. On comparing 0.12% CHX (15ml) versus 0.2% CHX (10ml) and 0.12% CHX (1min) versus 0.2% CHX (30s), the percentage of viable bacteria was higher with the 0.12% concentration. On comparing 0.2% CHX versus 0.2% CHX plus daily activities, the higher differences were detected after eating and chewing, followed by drinking. CONCLUSION: An increase in the volume of 0.12% or 0.2% CHX mouthwashes does not affect the duration of antimicrobial activity in saliva, whereas increasing the duration produces a marked increase in substantivity. Substantivity was greater with 0.2% CHX than 0.12% CHX. Eating, chewing or drinking significantly reduces the 0.2% CHX substantivity in saliva.

Evaluation of chlorhexidine substantivity on salivary flora by epifluorescence microscopy.

OBJECTIVE: To evaluate the in vivo antimicrobial activity of chlorhexidine (CHX) in saliva 7 h after its application using an epifluorescence microscopy technique. SUBJECTS AND METHODS: Fifteen volunteers performed a single mouthrinse with sterile water (SM-water) and with 0.2% CHX (SM-0.2% CHX). Saliva samples were taken at 30 s and 1, 3, 5 and 7 h after each application. The bacterial suspension was mixed with the SYTO 9/propidium iodide staining and observed using an Olympus BX51 microscope. The mean percentage of viable bacteria was calculated for each sample. RESULTS: In comparison with baseline values, the frequency of viable bacteria decreased significantly at 30 s after the SM-0.2% CHX (P < 0.001) and presented significant antibacterial activity up to 7 h after the mouthrinse (P < 0.001). In comparison with SM-water, the prevalence of viable bacteria was significantly lower at 30 s after the SM-0.2% CHX (P < 0.001) and showed a significant antibacterial effect up to 7 h after the mouthrinse (P < 0.001). CONCLUSIONS: Epifluorescence microscopy permits evaluating the antimicrobial activity of CHX on the salivary flora in real-time. Fluorescence assays could be particularly useful to analyse simultaneously the effect of antimicrobials that alter the cytoplasmic membrane integrity on different oral ecosystems.

In vivo bactericidal effect of 0.2% chlorhexidine but not 0.12% on salivary obligate anaerobes.

OBJECTIVES: To evaluate the in vivo antimicrobial activity on the salivary flora of a single mouthrinse of chlorhexidine (CHX) digluconate, analysing the influence of its concentration (0.2% versus 0.12%). METHODS: The study group was formed of 20 adult volunteers with a good oral health status. Non-stimulated saliva samples were collected under basal conditions and at 30s and 1h after a single mouthrinse with sterile water, 0.2% or 0.12% CHX digluconate. Serial dilutions were then performed and the resulting samples were cultured on conventional culture media for aerobes/facultative anaerobes and obligate anaerobes. The number of colony forming units (CFU/ml) was then determined and the results expressed on a decimal log scale (log(10)CFU/ml). RESULTS: A significant reduction in the total bacterial population was observed at 30s and 1h after the mouthrinse with both CHX concentrations; this antimicrobial activity was more pronounced on the obligate anaerobes. The antimicrobial activity of 0.2% CHX on the salivary flora at 30s and 1h after the mouthrinse was significantly greater than that of 0.12% CHX. Only 0.2% CHX showed bactericidal activity (differential factor> or =3 log(10)CFU/ml) against salivary obligate anaerobes. CONCLUSION: The greater antimicrobial activity of 0.2% CHX confirms the influence of the concentration on its antibacterial activity. In consequence, the CHX concentration seems to be an important factor to guarantee a high antibacterial activity in those clinical situations where it is required.

Effect of a neutralising agent on the evaluation of the antimicrobial activity of chlorhexidine on the bacterial salivary flora.

OBJECTIVE: To test the efficacy of a previously described neutralising agent to counteract any antimicrobial activity of 0.2% of chlorhexidine (CHX) mouthrinse on the salivary flora, which is only exhibited after sampling of surviving bacteria, resulting in false positive efficacy data. METHODS: Unstimulated salivary samples were collected of 20 volunteers under basal conditions and at 30s and 1h after of a single mouthrinse of 0.2% CHX. Each salivary sample was divided into 2 equal aliquots; one was mixed with neutralising agent (3% Tween 80, 0.3% lecithin and 0.1% cysteine) and the other with a control solution. The colony forming units (cfu/mL) were determined and expressed as logarithms (log(10)cfu/mL). RESULTS: At baseline, the total bacterial concentrations were similar, independently of the addition of neutralising solution or control solution (8.419+/-0.346log(10)cfu/mL and 8.462+/-0.474log(10)cfu/mL, respectively, p=0.440). At 30s performing the CHX mouthrinse, the bacterial load reduction was statistically significant between both sampling methods (1.917+/-1.275log(10)cfu/mL, p<0.001). One hour after performing the CHX mouthrinse, the bacterial load reduction was statistically significant between both sampling methods (0.537+/-0.706log(10)cfu/mL, p=0.003). CONCLUSIONS: Neutralising agent was not toxic to the bacterial salivary flora and effectively deactivated the "residual antimicrobial activity" of the 0.2% CHX (after exposure and during processing of samples). We propose the use of this neutralising agent when evaluating the antibacterial activity of CHX mouthrinses.