Método químico simplificado de desmineralización del esmalte dental humano / Simplified chemical method of demineralization in human dental enamel

Introducción: Se requieren métodos experimentales abreviados para simular las lesiones de desmineralización temprana de forma controlada y reproducible. Objetivo: Realizar una evaluación in vitro de un método simple de desmineralización incipiente del esmalte. Métodos: Estudio experimental aleatorizado con doble diseño factorial de réplicas. Se seleccionaron 12 terceros molares de sujetos humanos saludables para su desmineralización en solución de ácido láctico racémico. Las muestras se distribuyeron aleatoriamente: Grupo 1 (G1) (n= 6) ácido láctico a pH 2,4 y Grupo 2 (G2) (n= 6) ácido láctico a pH 5,4. A continuación, cada grupo se subdividió (n = 2) para evaluar el efecto de las soluciones a tres tiempos de exposición (7, 15 y 30 días) a 37 °C. La evaluación se llevó a cabo con estereomicroscopios, equipo de radiografía digital con un software de análisis digital de imágenes y microscopía de polarización. Se formuló una integración de los índices de respuesta y se realizó un ANOVA. Resultados: Los hallazgos visuales, radiográficos e histológicos mostraron que en el G1 en los tiempos 1 a 3, la desmineralización se caracterizó por una gran pérdida de la integridad del esmalte (80 por ciento a 100 por ciento). Visualmente, el G2 a los 7 días mostró opacidad y pérdida de brillo (16 por ciento) con preservación de la estructura superficial del esmalte. Conclusiones: Se demuestra que el empleo de ácido láctico durante 7 días a pH 5,4 produce una lesión clínica, radiográfica e histológica similar a una lesión temprana del esmalte(AU)

Introduction: Abridged experimental methods are required to simulate early demineralizing lesions in a controlled and reproducible way. Objective: Perform an in vitro evaluation of a simple method of incipient enamel demineralization. Methods: Randomized experimental study with a double factorial replication design. Twelve third molars from healthy human subjects were selected for demineralization in a racemic lactic acid solution. Samples were then distributed randomly: Group 1 (G1) (n= 6) lactic acid at pH 2.4 and Group 2 (G2) (n= 6) lactic acid at pH 5.4. Each group was then subdivided (n = 2) to evaluate the effect of the solutions at three exposure times (7, 15 and 30 days) at 37°C. The evaluation used stereomicroscopes, a digital x-rays apparatus with software for the digital analysis of images, and polarization microscopy. An integration of the response indices was formulated and ANOVA was performed. Results: Visual, radiographic and histological findings showed that G1 at time 1 through 3 displayed demineralization characterized by extensive loss (80 percent to 100 percent) of enamel integrity. Visually, G2 at 7 days exhibited opacity and loss of brightness (16 percent), with preservation of the surface structure of the enamel. Conclusions: It was shown that employing lactic acid for 7 days at pH 5.4 develops a clinical, radiographic and histological injury similar to an early enamel lesion(AU)

Anatomy, histochemistry and oxalic acid content of the leaflets of Averrhoa bilimbi and Averrhoa carambola

Abstract Averrhoa bilimbi L. and A. carambola L., Oxalidaceae, are the only two species of the genus Averrhoa L. Their leaves are widely used in folk medicine as an adjuvant in the treatment of diabetes. Some species may contain, for example, calcium oxalate crystals, which may lead to risk in its use when there is predisposition of individuals with reduced renal activity. Therefore, there are still few studies on the content of oxalic acid present in them, highlighting the importance of this investigation. The objective of this work was to conduct a comparative anatomical and histochemical study between the species and determining its content of oxalic acid. Semipermanent histological slides were prepared, following common plant anatomy procedures, for analysis of the leaflets in optical microscopy, polarization and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry. To determine the total, soluble and insoluble oxalate content was used titration with potassium permanganate. The anatomical characterization allowed identifying the characters useful in the differentiation of the species. The histochemistry revealed the location of the metabolites. Chemical microanalyses demonstrated that the crystals are of calcium oxalate. A. carambola presented the highest levels of total oxalate and soluble oxalate. The study assists in the identification and quality control of A. bilimbi and A. carambola and brings new data on its oxalic acid content, which are important, in view of the medicinal use of the species.

Reference Values for Normal Epidermal Thickness in Koreans: A Histopathologic Investigation / 대한피부과학회지

BACKGROUND: Epidermal thickness is a useful quantitative histopathological parameter to predict different skin conditions. For accurate diagnosis, the reference values of normal skin histology are essential. Until now, little data regarding epidermal thickness in normal Korean skin have been available. OBJECTIVE: To investigate the thickness of the epidermis, stratum corneum, and cellular epidermis by skin biopsy and to compare their regional, age, and sex variations in Koreans. METHODS: A total of 119 normal human skin tissues from 117 subjects were included. Skin specimens were preserved in sections by formalin-paraffin techniques and measured by performing light microscopy and using a calibrated ruler. RESULTS: The mean thickness of the epidermis was 140.6±32.6 µm (mean±standard deviation). Significant regional variations of epidermal thickness were found (p0.5) or sex (p>0.05, except for the thickness of the stratum corneum of the legs [p=0.007]). CONCLUSION: Regional variations of epidermal thickness were demonstrated. These variations were mostly independent of age or sex, which conflicts somewhat with previous studies. We present this research as a preliminary study, which may provide reference values for skin histopathology and epidermal thickness in normal Korean skin.

Relationship between meiotic spindles visualization and intracytoplasmic sperm injection outcomes in human oocytes / 대한해부학회지

In assisted reproductive techniques, the operator attempts to select morphologically best embryos to predict embryo viability. Development of polarized light microscope, which evaluates the oocytes' spindles according to birefringence of living cells, had been helpful in oocyte selection. The aim of this study is evaluating the relationship between meiotic spindles visualization and intracytoplasmic sperm injection (ICSI) outcomes in human oocytes. In this study, 264 oocytes from 24 patients with an average age of 30.5±7.5 years with infertility duration of 1 to 10 years were collected. The oocytes were randomly allocated to the control injection group (n=126) and the oocyte imaging group (spindle-aligned group) (n=138). In the spindle-aligned group, the meiotic spindle was identified by means of polarized light microscope to align the spindle at 6 or 12 o'clock. Then the spindle-aligned group was divided into three sub-groups based on spindle morphology: fine, average, and (poor). After ICSI, embryos were checked every 24 hours and scored; 72 hours later, high-grade embryos were transferred intravaginally to uterus. This study showed that the fertilization rate in the spindle-aligned group was higher than the control group (P<0.05). After cleavage, a positive correlation was observed between spindle morphology and embryo morphology. Among the sub-groups of spindle-aligned group, the embryos' morphology of the fine group was better than the other subgroups and embryos of the poor group had lower quality and more fragmentation. The results revealed that the selection of oocytes based on meiotic spindle imaging can significantly improve the rate of fertilization and embryo cleavage and certainly increase the rate of implantation.

Histological and microhardness evaluation of early artificial carious lesions in human and bovine enamel: in vitro study / Avaliação histológica e de microdureza de lesões incipientes de cárie em esmalte humano e bovino: estudo in vitro

Objective: Early carious lesions in bovine and human enamel developed in vitro using a pH cycling regimen were compared. Material and Methods: Fifteen central bovine incisors and fifteen recently extracted human third molars were randomly divided into two groups: ten for the cross-sectional microhardness test (MT) and five for polarized light microscopy (PLM) analysis. Enamel blocks measuring 5 x 5 mm were made from the buccal face of the teeth. The blocks used for the MT were sliced into two halves: “A” and “B”. “A” slices were embedded in acrylic resin, with the face of the dentin-enamel junction left exposed for the MT prior to pH cycling. “B” slices and whole blocks were coated with acid-resistant varnish, except a 3 x 3 mm central window, and submitted to the pH cycling regimen (demineralizing solution for 3 h and remineralizing solution for 21 h) over five consecutive days. The “B” slices were then submitted to the MT and the whole blocks were processed for the PLM study. Results: The PLM analysis revealed shallow, extensive lesions in the bovine enamel, hardly showing the superficial, dark and translucent zones, as well as deep cavity lesions in the human enamel, with the body of the lesion and the dark zone evident. The MT revealed a significant decrease in microhardness in the superficial levels of the bovine enamel caries and at all depth levels of the human enamel caries. Conclusion: The pH cycling regimen adopted led to the development of deeper and more demineralized carious lesions in human enamel than bovine enamel

Objetivo: Comparar lesões incipientes de cárie em esmaltes humano e bovino desenvolvidas in vitro através de ciclagem de pH. Material e Métodos: Quinze incisivos centrais bovinos e quinze terceiros molares humanos inclusos recém-extraídos foram aleatoriamente divididos em dois grupos: dez para o teste de microdureza tranversal (MT) e cinco para a análise por microscopia de luz polarizada (MLP). Blocos de esmalte com dimensões de 5 x 5 mm foram confeccionados a partir da face vestibular dos dentes. Os blocos utilizados para MT, a qual foi determinada em cinco níveis de profundidade, foram seccionados em duas metades, designadas por “A” e “B”. As fatias “A” foram submetidas ao teste de MT previamente à ciclagem de pH. Já as fatias “B” e os blocos de esmalte foram recobertos por verniz ácido-resistente, exceto por uma janela de 3 x 3 mm, e então submetidos à ciclagem de pH (soluções desmineralizadora por 3 h e remineralizadora por 21 h) por 5 dias consecutivos. As fatias “B” foram então submetidas a MT e os blocos foram processados para a MLP. Resultados: A análise por MLP revelou lesões rasas e extensas no esmalte bovino, com zonas superficial, escura e translúcida pouco visíveis; no esmalte humano, as lesões apresentaram-se profundas e cavitadas, com o corpo da lesão e a zona escura evidentes. A MT revelou significante diminuição na microdureza nos níveis superficiais do esmalte bovino e em todas as profundidades avaliadas do esmalte humano após a ciclagem de pH. Conclusão: A ciclagem de pH levou ao desenvolvimento de lesões de cárie mais profundas e com maior desmineralização no esmalte humano em comparação ao esmalte bovino.

Colagenoma eruptivo em paciente HIV+ / Eruptive collagenoma in an HIV-positive patient

Colagenomas são hamartomas do tecido conjuntivo gerados por aumento anormal do colágeno dérmico. O colagenoma eruptivo caracteriza-se por pequenos nódulos duros, assintomáticos, sem relato de trauma ou processo inflamatório prévios. Descreve-se caso de paciente do sexo masculino, de 28 anos, que há 10 anos notou surgimento espontâneo de lesões papulosas no tronco, nos membros superiores e abdômen, e há três anos descobriu ser soropositivo para HIV. O diagnóstico diferencial, a classificação da doença como entidade própria e a associação casual com o HIV são discutidos, bem como a necessidade da realização da coloração vermelho Picrosirius/luz polarizada para confirmação diagnóstica dos colagenomas.

Collagenomas are connective tissue nevi predominantly composed of excessive dense and coarse collagen in the dermis. Eruptive collagenoma is a rare disorder occurring in young adults as asymptomatic dermal nodules, with no previous history of injury or inflammation and usually localized on the back. We describe the case of a 28-year-old male patient who was examined for numerous asymptomatic little nodules on the trunk and upper arms, which appeared ten years ago with no previous inflammation or injury. Three years ago the patient was diagnosed HIV-positive. Differential diagnoses, classification of the disease as an autonomous entity, its casual association with HIV, as well as the real need for picrosirius red staining to confirm diagnosis of collagenoma are discussed.

Birefringent Particles as an Effective Factor in Usual Interstitial Pneumonia

BACKGROUND: It has long been recognized that birefringent paticles (BP) are associated with pulmonary disease. And there is increasing evidence that BP cause fibrotic reaction within the lung depending on both particle size and composition. METHODS: We collected 41 cases of usual interstitial pneumonia (UIP) and 101 cases of normal lung tissue from control group including squamous cell carcinoma, adenocarcinoma and bullae. BPs in the 0.1 to 10 micrometer size range under polarizing microscope was measured and counted by image analyzer. RESULTS: BP counts are mean 244.05/10 HPF in UIP and 71.4/10 HPF in control group. BPs in UIP is three times more than control (p=0.000). It increased significantly by the age of patients (p=0.000). CONCLUSIONS: BPs in lung might be important cause of inflammation and fibrosis in UIP.

The Histochemical Distribution Of Collagen In The Osteoarthritic Human Cartilage / 대한류마티스학회지

OBJECTIVE: Osteoarthritis is a disorder or group of disorders affecting synovial joint, characterized at the tissue level by degenerative, regenerative and reparative structural changes in cartilage, synovium and bone. The histopathological understanding of osteoarthritis would help to clear the pathogenesis and evaluate the activity and progression of the disease. We studied the histochemical distribution of collagen in the search for and accurate morphometric m~rker for osteoarthritic progression. METHODS: The immunohistochemical analysis by monoclonal antibodies to type I, II and III collagen, the Masson's trichrome stain and the Picrosirius stain and polarization microscopy were performed in 10 osteoarthritis cartilages and 1 normal control cartilage. RESULTS: 1)By the immunohistochemical analysis, type II collagen was diffusely expressed in both normal and osteoarthritis cartilage but the expression of type I and III collagen was only shown around chondrocytes in the osteoarthritis cartilage. 2) There was no difference in Masson's trichrome stain of the normal and osteoarthritis cartilage. 3) By the Picrosirius stain and polarization microscopy, there was less diffuse birefringence of collagen and increased perichondronal birefringence in the osteoarthritis cartilage in comparison to normal cartilage. CONCLUSIONS: The Picrosirius-polarization method may be considered one of the useful morphometriic methods for the progression of osteoarthrits.