Bile duct ligation in neonatal rats: is it a valid experimental model for biliary atresia studies?

BA is the most important disease requiring liver transplantation in children. Common BDL in rats is a classic experimental model to study biliary obstruction. The response of the neonatal animal to BDL has yet to be completely understood and few reports have focused on the behavioral differences of the liver between neonatal and adult animals. Ninety newborn Wistar rats aged six days, weighing 8.0-13.9 g, and 90 adult Wistar rats weighing 199.7-357.0 g, were submitted to BDL. After surgery, they were randomly divided and killed on the 3rd, 5th, 7th, 14th, 21st and 28th day post-BDL. Hepatic biopsies were obtained and the following were measured: (i) semiquantification of the bile ductule proliferation and inflammatory infiltrate by HE stain, (ii) quantification of portal and periportal fibrosis with the Sirius-red stain. Although the initial response of ductule proliferation and inflammatory infiltrate were less intense in the newborn animal, the portal and periportal fibrosis were higher when compared with adult animals (p < 0.0491). These findings may contribute to the understanding of the pathophysiology of BA.

Nonablative 1,064-nm Nd:YAG laser for treating atrophic facial acne scars: histologic and clinical analysis.

BACKGROUND: Non-ablative methods have been attempted in treating atrophic facial scars, but the histologic findings do not always coincide with the clinical results and patient satisfaction. OBJECTIVE: To study the effects and safety of the Nd:YAG laser for treating atrophic facial scars. MATERIAL AND METHODS: Twelve subjects (skin phototypes II-V) with mild to moderate atrophic facial acne scars received five monthly treatments with 1,064 nm Nd:YAG laser and were photographed before, in the middle of, and 6 months after the last treatment. Histologic evaluations were performed on skin biopsies obtained before treatment and 1 month after the last session. Collagen quantification per area, before and after the treatment, was performed by morphometry, with computerized image analysis. Patient satisfaction and clinical condition were assessed using standard grading scales. RESULTS: Mild to moderate clinical improvement was observed in most patients. Photographic assessment of scars found visible cosmetic improvement in eleven patients. All patients were satisfied. There were statistically significant collagen increases in the dermis following the treatment. Side effects were limited to mild transient erythema and increased skin sensitivity after the procedure. CONCLUSIONS: The 1,064 nm Nd:YAG laser is a safe and effective nonablative method for improving atrophic scars, even in darker skin.

Effect of intertrochanteric osteotomy on the proximal femur of rabbits: assessment with power Doppler sonography and scintigraphy.

OBJECTIVE: In bone injury, repair results in local increased vascularity and bone marrow remodeling. Characterizing the vascular and metabolic imaging patterns of the proximal femur following an intertrochanteric osteotomy may help clinicians decide proper management of the patient. Our objective was to measure Doppler sonography and scintigraphy interval changes in the proximal femur following intertrochanteric osteotomy and compare imaging and histomorphometric measurements in the late post-operative stage (6 weeks after surgery) in a rabbit model of bone injury. MATERIALS AND METHODS: Both hips of 12 adult rabbits were imaged with power Doppler sonography and scintigraphy prior to and after (7 days and 6 weeks) unilateral osteotomy. Accuracy of the imaging methods was evaluated using hip operative status and histomorphometric results (vascular fractional area and number of vessels per area unit) as reference standard measures. RESULTS: A significant difference in the mean number of pixels was noted between operated and non-operated femura in late post-operative power Doppler examinations (P=0.049). Although without reaching statistical significance, the AUC of Doppler measurements (AUC=0.99) was numerically greater than the AUC of scintigraphy measurements (AUC=0.857+/-0.099) (P=0.15) in differentiating proximal femura with regard to their fractional vascular areas in the late post-operative stage. In contrast, scintigraphy tended to perform better (AUC=0.984+/-0.022) than Doppler ultrasound (AUC=0.746+/-0.131) to demonstrate the vascularity intensity per area unit (P=0.07) in the late stage. CONCLUSION: Our results warrant further investigation to determine the value of different imaging modalities for assessment of pathologic changes following hip surgery. Power Doppler sonography demonstrated larger AUCs (representing higher accuracy) for the discrimination of vascular fractional areas and scintigraphy, for discrimination of the number of vessels per area unit.

[Homologous scleral and dura mater grafts in rabbit eyes: a comparative histopathological analysis]. / Enxertos homólogos de esclera e dura-máter em olhos de coelhos: análise histopatológica comparativa.

PURPOSE: To evaluate tissue reaction to implantation of homologous scleral and dura mater grafts. METHODS: Experimental surgeries were performed on 41 albine New Zealand rabbits; two rabbits were selected at random to be graft donors. Thirty rabbits were divided into two groups: group D and group E, receiving grafts of homologous tissues. The remaining nine animals comprised the control group (DE) and were submitted to surgery but with no graft. The eyes were enucleated and samples collected two, six and 12 weeks after the experiment, comprising subgroups I, II and III. RESULTS: A qualitative histopathological analysis was performed together with a comparative semi-quantitative study on vascularization and inflammatory infiltrate in the transplanted sclera and dura mater. Histomorphometry was conducted based on measurements of the grafts with an image analyzing system. There was no statistically significant difference when comparing vascularization, inflammatory infiltrate and measurements between subgroup I in relation to sclera and dura mater, nor in subgroup II. Subgroup III was not compared, since only fragments of dura mater grafts were considered. CONCLUSIONS: The dura mater graft presented intense absorption and progressive replacement of loose connective tissue. And the scleral graft showed discreet absorption in the periphery with formation of a more evident fibrous membrane, integrating the graft into the host sclera.

A comparison of the effects of pneumoperitoneum and laparotomy on natural killer cell mediated cytotoxicity and Walker tumor growth in Wistar rats.

BACKGROUND: Surgical stress promotes impaired immunological function, which contributes to tumor growth. Natural killer activity (NKA) has a protective role in immunity to tumors. So, the aim of this experimental study was to assess tumor growth and (NKA) after pneumoperitoneum and laparotomy. METHODS; Sixty male Wistar rats were divided into three groups (anesthesia, CO2 pneumoperitoneum and laparotomy) plus ten controls. All experimental animals were inoculated subcutaneously with 8 x 105 Walker carcinosarcoma 256 cells. Animals were sacrificed on 1st(POD1) and 8th (POD8) postoperative day. Tumors were excised and weighed. RESULTS: On POD1 all animals had diminished NKA when compared to controls; NKA after pneumoperitoneum was significantly greater than after laparotomy. On POD8 all animals, except after laparotomy, reached NKA at controls levels. Tumor weight was significantly greater after laparotomy when compared to pneumoperitoneum. CONCLUSIONS: Pneumoperitoneum causes a less depressed NKA and less tumor growth when compared to laparotomy.

Vascular density of the posterior tibial tendon: a cadaver study.

BACKGROUND: Degenerative pathology of the posterior tibial tendon, a common cause of foot and ankle dysfunction, frequently affects women over 40 years of age. Its etiology is still controversial. The literature reports decreased vascularization coinciding with the most common site of the lesion, near the medial malleolus. METHODS: Forty pairs of PTT obtained from human cadavers were transversally cut into six levels, from the musculotendon transition to its insertion point. In each segment, a histologic cut was made and stained with Masson's trichrome allowing viewing of the vascular structure of the tendon under a light microscope. By using an integrating eyepiece on the microscope, vascular density was calculated. This verified any variation of the vascular concentration in the normal tendon, a possible cause of its degeneration. RESULTS: When the results were compared by side, sex, and age, no statistically significant difference was observed. When the levels were compared, no area of decreased vascularization was seen in the midportion of the tendons, the most common site of degeneration of the posterior tibial tendon. CONCLUSION: These results indicate that an area of decreased vascularity is not a factor in degeneration of the posterior tibial tendon at the medial malleolus.

The anterior sylvian point and the suprasylvian operculum.

OBJECT: The sylvian fissure or lateral sulcus is the most identifiable feature of the superolateral brain surface and constitutes the main microneurosurgical corridor, given the high frequency of approachable intracranial lesions through this route. The anterior sylvian point (ASyP) divides this fissure in its main anterior and posterior rami and was evaluated in this study for its morphology, exact location, and sulcal and neural relationships to assess its suitability as an initial, visually identifiable landmark for further neuroimaging and intraoperative estimation of its adjoining suprasylvian structures. METHODS: This study is based on 32 formalin-fixed cerebral hemispheres. The brains were removed from the skulls of 16 cadavers after the introduction of plastic catheters through properly positioned burr holes; the number of specimens for some of the analyzed data differed because of incorrect positioning of catheters or damage to the studied structures caused by the initial steps of the study. The ASyP had a cisternal aspect in 94% of the specimens and was always located inferior to the triangular part of the inferior frontal gyrus, 2.3 6 0.5 cm in front of the inferior rolandic point. The ASyP was located underneath the 1.5-cm-diameter cranial area of the anterior aspect of the squamous suture. Its adjoining structures that compose the suprasylvian operculum have constant basic morphological configurations. CONCLUSIONS: The ASyP underlies the anterior aspect of squamous suture just behind the pterion, can be easily recognized, and constitutes a reliable initial sulcal landmark for further estimation of the suprasylvian sulcal and gyral structures. The suprasylvian operculum can be understood as a series of convolutions roughly arranged as a V-shaped convolution, with its vertex constituted by the ASyP, followed by three U-shaped convolutions and one C-shaped convolution.

Engraftment of human adipose derived stem cells delivered in a hyaluronic acid preparation in mice.

PURPOSE: To evaluate the implant of human adipose derived stem cells (ADSC) delivered in hyaluronic acid gel (HA), injected in the subcutaneous of athymic mice. METHODS: Control implants -HA plus culture media was injected in the subcutaneous of the left sub scapular area of 12 athymic mice. ADSC implants: HA plus ADSC suspended in culture media was injected in the subcutaneous, at the contra lateral area, of the same animals. With eight weeks, animals were sacrificed and the recovered implants were processed for extraction of genomic DNA, and histological study by hematoxilin-eosin staining and immunufluorescence using anti human vimentin and anti von Willebrand factor antibodies. CONTROLS: Not visualized at the injection site. An amorphous substance was observed in hematoxilin-eosin stained sections. Human vimentin and anti von Willebrand factor were not detected. No human DNA was detected. ADSC implants - A plug was visible at the site of injection. Fusiform cells were observed in sections stained by hematoxilin- eosin and both human vimentin and anti von Willebrand factor were detected by immunofluorescence. The presence of human DNA was confirmed. CONCLUSION: The delivery of human adipose derived stem cells in preparations of hyaluronic acid assured cells engraftment at the site of injection.

A lipocalin-derived Peptide modulating fibroblasts and extracellular matrix proteins.

Lipocalin family members have been implicated in development, regeneration, and pathological processes, but their roles are unclear. Interestingly, these proteins are found abundant in the venom of the Lonomia obliqua caterpillar. Lipocalins are ß-barrel proteins, which have three conserved motifs in their amino acid sequence. One of these motifs was shown to be a sequence signature involved in cell modulation. The aim of this study is to investigate the effects of a synthetic peptide comprising the lipocalin sequence motif in fibroblasts. This peptide suppressed caspase 3 activity and upregulated Bcl-2 and Ki-67, but did not interfere with GPCR calcium mobilization. Fibroblast responses also involved increased expression of proinflammatory mediators. Increase of extracellular matrix proteins, such as collagen, fibronectin, and tenascin, was observed. Increase in collagen content was also observed in vivo. Results indicate that modulation effects displayed by lipocalins through this sequence motif involve cell survival, extracellular matrix remodeling, and cytokine signaling. Such effects can be related to the lipocalin roles in disease, development, and tissue repair.

Intense pulsed light in photoaging: a clinical, histopathological and immunohistochemical evaluation.

BACKGROUND: Intense pulsed light has been used in the treatment of photoaging without a full understanding of its mechanism of action. OBJECTIVE: To study the effect of intense pulsed light on photoaging and on the skin immune response by means of a clinical and histopathological study, evaluating Langerhans cells (CD1), expression of intercellular adhesion molecule, of CD4 and CD8 lymphocytes and quantification of collagen and elastic fibers. METHODS: In 2006 a total of 26 patients, aged 40 to 65 years, with phototypes II to III (Fitzpatrick scale), were treated for photoaging using intense pulsed light in five sessions with a monthly interval. All the patients were subjected to histological and immunohistochemical evaluation 6 months after treatment. RESULTS: At the end of the treatment clinical improvement was observed in 76.92% of cases. This improvement was associated to a significant increase of collagen (51.33%) and elastic (44.13%) fibers. Intense pulsed light treatment led to a reduction of CD4 lymphocytes and did not alter the amount of CD8 lymphocytes. It also led to a significant increase of small, nonectatic blood vessels, positive intercellular adhesion molecule. CONCLUSION: Facial treatment with intense pulsed light promoted major clinical improvement that was confirmed by histological examination of the skin. This technique is a good treatment option for skin photoaging because it is non-ablative, safe and effective.

Parathyroid gland anatomical distribution and relation to anthropometric and demographic parameters: a cadaveric study.

Parathyroid glands play an important role in controlling calcium levels, which influence muscular contraction and neurotransmission. The number of variants, localization and ectopic positions make these glands tricky during surgical exploration. Detailed anatomical knowledge of these glands is fundamental to avoid postsurgical hypoparathyroidism, such as failures during thyroidectomy and parathyroid procedures. The purposes of this work were to study and report practical knowledge for surgeons in order to localize the glands. Dissections were performed on 56 cadavers. Gland identity was confirmed by histological study. Also, mediastinal tissue and the carotid sheath were treated with Carnoy's solution to identify ectopic glands. The thyroid gland was divided and sliced to identify parathyroid glands in the parenchymal and subcapsular space. Four or more parathyroid glands were found in 89.3% of the studied specimens. Mean gland weight was 33.1 mg, and its mean measurements were 6.7 × 3.9 × 2.0 mm. In more than 90% of the cases there was a correlation with the inferior laryngeal nerve and the parathyroid glands: the upper glands were located in medial positions, and the lower ones were found to be located laterally. In 42.8% of cases at least one ectopic gland was observed. The main ectopic regions were the mediastinum and thymus (19.6%), thyroid subcapsular space (12.5%) and thyroid parenchyma (5.4%). Quantity, gland characteristics and location were not influenced by anthropometric and demographic parameters. Here we show the high incidence of parathyroid glands positioned at "abnormal" locations, and as a controversial topic in endocrine surgery, this matter must be continuously studied and reported in the literature.

Comparison between the effects of platelet-rich plasma and bone marrow concentrate on defect consolidation in the rabbit tibia.

OBJECTIVE: To perform a comparative analysis of the effects of platelet-rich plasma and centrifuged bone marrow aspirate on the induction of bone healing in rabbits. METHOD: Twenty adult, male New Zealand rabbits were randomly separated into two equal groups, and surgery was performed to create a bone defect (a cortical orifice 3.3 mm in diameter) in the proximal metaphysis of each rabbit's right tibia. In the first group, platelet-rich plasma was implanted in combination with ß-tricalcium phosphate (platelet-rich plasma group), and in the second group, centrifuged bone marrow in combination with ß-tricalcium phosphate (centrifuged bone marrow group) was implanted. After a period of four weeks, the animals were euthanized, and the tibias were evaluated using digital radiography, computed tomography, and histomorphometry. RESULTS: Seven samples from each group were evaluated. The radiographic evaluation confirmed the absence of fractures in the postoperative limb and identified whether bone consolidation had occurred. The tomographic evaluation revealed a greater amount of consolidation and the formation of a greater cortical bone thickness in the platelet-rich plasma group. The histomorphometry revealed a greater bone density in the platelet-rich plasma group compared with the centrifuged bone marrow group. CONCLUSION: After four weeks, the platelet-rich plasma promoted a greater amount of bone consolidation than the bone marrow aspirate concentrate.

Variation in the distribution of trace elements in renal cell carcinoma.

The development of cancer is a complex, multistage process during which a normal cell undergoes genetic changes that result in phenotypic alterations and in the acquisition of the ability to invade other sites. Inductively coupled plasma optical emission spectroscopy was used to estimate the contents of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, and Zn in healthy kidney and renal cell carcinoma (RCC), and significant differences were found for all elements. Along with the progression of the malignant disease, a progressive decrease of Cd and K was observed. In fact, for Cd, the concentration in stage T4 was 263.9 times lower than in stage T1, and for K, the concentration in stage T4 was 1.73 times lower than in stage T1. Progressive accumulation was detected for P, Pb, and Zn in stage T4. For P, the concentration in stage T4 was 11.1 times higher than in stage T1; for Pb, the concentration in stage T4 was 232.7 times higher than in T1; and for Zn, the concentration in T4 was 8.452 times higher than in T1. This study highlights the marked differences in the concentrations of selected trace metals in different malignant tumor stages. These findings indicate that some trace metals may play important roles in the pathogenesis of RCC.

Engraftment of human adipose derived stem cells delivered in a hyaluronic acid preparation in mice / Implante de células tronco do tecido adiposo humano numa preparação de ácido hialurônico em camundongos

PURPOSE: To evaluate the implant of human adipose derived stem cells (ADSC) delivered in hyaluronic acid gel (HA), injected in the subcutaneous of athymic mice. METHODS: Control implants -HA plus culture media was injected in the subcutaneous of the left sub scapular area of 12 athymic mice. ADSC implants: HA plus ADSC suspended in culture media was injected in the subcutaneous, at the contra lateral area, of the same animals. With eight weeks, animals were sacrificed and the recovered implants were processed for extraction of genomic DNA, and histological study by hematoxilin-eosin staining and immunufluorescence using anti human vimentin and anti von Willebrand factor antibodies. RESULTS: Controls: Not visualized at the injection site. An amorphous substance was observed in hematoxilin-eosin stained sections. Human vimentin and anti von Willebrand factor were not detected. No human DNA was detected. ADSC implants - A plug was visible at the site of injection. Fusiform cells were observed in sections stained by hematoxilin- eosin and both human vimentin and anti von Willebrand factor were detected by immunofluorescence. The presence of human DNA was confirmed. CONCLUSION: The delivery of human adipose derived stem cells in preparations of hyaluronic acid assured cells engraftment at the site of injection.

OBJETIVO: Avaliar o implante de células tronco do tecido adiposo humano (CTTAH) em gel de ácido hialurônico (AH), injetados no tecido subcutâneo de camundongos atímicos. MÉTODOS: Implantes controle - HA com meio de cultura foram injetados no tecido subcutâneo da região infraescapular esquerda de 12 camundongos atímicos. Implantes de CTTAH: HA com CTTAH suspensas em meio de cultura foi injetado no subcutâneo da região contra lateral, dos mesmos animais. Com oito semanas, os animais foram sacrificados e os implantes recuperados foram processados para extração de DNA genômico, estudo histológico por coloração por hematoxilina eosina e imnuoflurescência utilizando anticorpos anti vimentina humana e anti fator de von Willebrand. RESULTADOS: Controles - implantes não visualizados no local da injeção. Uma substância amorfa foi observada nos cortes corados por hematoxilina eosina. Vimentina humana e fator anti von Willebrand não foram identificados. DNA humano não foi detectado. Implantes de CTTAH - Uma massa era visível no local da injeção. Células fusiformes foram observadas nos corte corados com hematoxilina eosina. Tanto vimentina humana quanto fator de von Willebrand foram identificados pela imunofluorescência. A presença de DNA humano foi confirmada. CONCLUSÃO: O implante de células tronco do tecido adiposo humano em veículo de ácido hialurônico gel assegurou a manutenção das células no local do implante.

Stem cells from the fat tissue of rabbits: an easy-to-find experimental source.

Stem cells, because of their pluripotentiality and unlimited capacity for self-renewal, project great promise for tissue engineering and are expected to allow significant advances for distinct reconstructive procedures. This study aimed to establish a versatile experimental model with potential application to distinct lines of research in plastic surgery. The search was guided by the need for mesenchymal stem cells that can be easily obtained for laboratory research. The authors studied the anatomy of a number of animals as potential donors and indicated the white New Zealand rabbit (Oryctolagus cuniculus) for this purpose. The animals of this species present definite areas of lipid tissue on their back, allowing easy access to the tissue by either exeresis or liposuction.

Análise imunohistoquímica da pele fotoenvelhecida após tratamento com o ácido 5 delta aminolevulínico / Immunohistochemical analysis of photodamaged skin after treatment with delta 5-aminolevulinic acid

Introdução: O mecanismo de destruição da célula alvo na terapia fotodinâmica compreende a destruição celular direta, a injúria ao estroma vascular e a ativação do sistema imune. Objetivo: Estudar a resposta imune da pele humana fotoenvelhecida ao tratamento com terapia fotodinâmica. Métodos: Treze pacientes femininas foram submetidas a três sessões de tratamento com o ácido 5 delta aminolevulínico associado à luz de diodo de 630nm. Foi avaliada a resposta imunohistoquímica do sistema imunológico da pele por meio dos marcadores: anti-CD1a,anti-CD4+, anti-CD8+, anti-TNFa, anti-IFN¿ e anti-IL4; antes, 24 horas após a primeira sessão e 21 dias após a terceira sessão. Os dados foram analisados por meio de estatística descritiva: média, desvio padrão, valor mínimo e máximo, e mediana. Resultados: 21 dias após o ultimo tratamento houve diminuição do número de linfócitos CD4 e CD8, aumento de interleucina 4 na epiderme e derme, diminuição do TNF-a na epiderme e aumento na derme. A população de células Langerhans e do INF-¿ não mudou. Conclusão: Em relação ao sistema imune esta terapia não mostrou alteração das células de Langerhans e, por isso, pouca imunossupressão local. A apoptose dos linfócitos CD4 e CD8 foi evidenciada sugerindo que a terapia fotodinâmica possa ser útil em doenças inflamatórias. O estudo mostrou diminuição do TNFa na epiderme e aumento na derme além do aumento da IL4 em ambas, o que sugere resposta do tipo humoral neste protocolo, o que também pode ser evidenciado pela ausência do INFy.

Introduction: Photodynamic therapy destroys target cells by directly harming them, injuring the vascular stroma, and activating the immune system. Objective: To study photoaged skin's immune response to photodynamic therapy. Methods: Thirteen female patients underwent three treatment sessions with delta 5-aminolevulinic acid combined with 630 nm diode light. The immunohistochemical response of the skin's immune system was evaluated using the markers anti-CD1a, anti-CD4+, anti-CD8+, anti-TNFa, anti-IFNy and anti-IL4 before, 24 hours after the first session, and 21 days after the third session. Results: At the final evaluation, patients demonstrated a decrease in CD4 and CD8 lymphocytes, an increase in interleukin-4 in the epidermis and dermis, and a reduction and an increase of TNF-a in the epidermis and dermis, respectively. The Langerhans cell and INF-y populations remained unchanged. Conclusion: Regarding the immune system, photodynamic therapy did not cause changes in Langerhans cells; therefore, there was little local immunosuppression. CD4 and CD8 lymphocyte apoptosis was observed, suggesting that photodynamic therapy can be useful in treating inflammatory diseases. The changes in TNF-a and an increase of IL4 in the dermis and epidermis suggest a humoral type response, which was also evidenced by the absence of INFy.

Luz intensa pulsada no fotoenvelhecimento: avaliação clínica, histopatológica e imuno-histoquímica / Intense pulsed light in photoaging: a clinical, histopathological and immunohistochemical evaluation

FUNDAMENTOS: A luz intensa pulsada tem sido muito utilizada no tratamento do fotoenvelhecimento sem completo conhecimento de seu mecanismo de ação. OBJETIVO: Estudar a ação da luz intensa pulsada no fotoenvelhecimento e na resposta imunológica cutânea por meio de estudo clínico, histopatológico, avaliando células de Langerhans (CD1), expressão da molécula de adesão intercelular, de linfócitos CD4 e CD8 e quantificação de colágeno e fibras elásticas. MÉTODOS: Um total de 26 pacientes, com idades entre 40 e 65 anos, com fototipos II a III de Fitzpatrick, foram tratadas do fotoenvelhecimento usando LIP, em 5 sessões, com intervalo mensal, durante o ano de 2006. Todas as pacientes foram submetidas à avaliação histológica e imuno-histoquímica 6 meses após o tratamento. RESULTADOS: Ao término do tratamento, houve melhora clínica em 76,92 por cento dos casos, estando relacionada ao aumento significante de fibras colágenas (51,33 por cento) e elásticas (44,13 por cento). O tratamento com luz intensa pulsada promoveu redução de linfócitos CD4 e não alterou a intensidade de linfócitos CD8. Além disso, promoveu aumento significante de pequenos vasos sanguíneos, não ectásicos, molécula de adesão intercelular positivos. CONCLUSÃO: O tratamento facial com luz intensa pulsada promoveu intensa melhora clínica que foi comprovada pelo estudo histopatológico da pele, constituindo boa opção de tratamento para o fotoenvelhecimento cutâneo, por ser técnica não- ablativa, segura e eficaz.

BACKGROUND: Intense pulsed light has been used in the treatment of photoaging without a full understanding of its mechanism of action. OBJECTIVE: To study the effect of intense pulsed light on photoaging and on the skin immune response by means of a clinical and histopathological study, evaluating Langerhans cells (CD1), expression of intercellular adhesion molecule, of CD4 and CD8 lymphocytes and quantification of collagen and elastic fibers. METHODS: In 2006 a total of 26 patients, aged 40 to 65 years, with phototypes II to III (Fitzpatrick scale), were treated for photoaging using intense pulsed light in five sessions with a monthly interval. All the patients were subjected to histological and immunohistochemical evaluation 6 months after treatment. RESULTS: At the end of the treatment clinical improvement was observed in 76.92 percent of cases. This improvement was associated to a significant increase of collagen (51.33 percent) and elastic (44.13 percent) fibers. Intense pulsed light treatment led to a reduction of CD4 lymphocytes and did not alter the amount of CD8 lymphocytes. It also led to a significant increase of small, nonectatic blood vessels, positive intercellular adhesion molecule. CONCLUSION: Facial treatment with intense pulsed light promoted major clinical improvement that was confirmed by histological examination of the skin. This technique is a good treatment option for skin photoaging because it is non-ablative, safe and effective.

Comparison between the effects of platelet-rich plasma and bone marrow concentrate on defect consolidation in the rabbit tibia

OBJECTIVE: To perform a comparative analysis of the effects of platelet-rich plasma and centrifuged bone marrow aspirate on the induction of bone healing in rabbits. METHOD: Twenty adult, male New Zealand rabbits were randomly separated into two equal groups, and surgery was performed to create a bone defect (a cortical orifice 3.3 mm in diameter) in the proximal metaphysis of each rabbit's right tibia. In the first group, platelet-rich plasma was implanted in combination with β-tricalcium phosphate (platelet-rich plasma group), and in the second group, centrifuged bone marrow in combination with β-tricalcium phosphate (centrifuged bone marrow group) was implanted. After a period of four weeks, the animals were euthanized, and the tibias were evaluated using digital radiography, computed tomography, and histomorphometry. RESULTS: Seven samples from each group were evaluated. The radiographic evaluation confirmed the absence of fractures in the postoperative limb and identified whether bone consolidation had occurred. The tomographic evaluation revealed a greater amount of consolidation and the formation of a greater cortical bone thickness in the platelet-rich plasma group. The histomorphometry revealed a greater bone density in the platelet-rich plasma group compared with the centrifuged bone marrow group. CONCLUSION: After four weeks, the platelet-rich plasma promoted a greater amount of bone consolidation than the bone marrow aspirate concentrate.

Mechanoreceptors and nerve endings of the triangular fibrocartilage in the human wrist.

PURPOSE: To increase our understanding of the mechanism of pain and the sensation of wrist instability by studying the distribution of the mechanoreceptors in the triangular fibrocartilage (TFC). METHODS: The distribution and density of the nerve endings were investigated in 34 TFC specimens obtained from human cadavers. We studied the dorsal, palmar, ulnar, radial, and central areas after staining by a modified gold chloride technique. RESULTS: The free nerve endings, responsible for sensing pain, predominate in the ulnar and dorsal areas. The Vater-Pacini corpuscles predominate in the radial and dorsal area, promoting perception of the onset or cessation of movement and mechanical stress change. The Golgi-Mazzoni corpuscles were more frequent in the ulnar and ventral areas, linking these areas to function of slow adaptation and sensation of extreme movements. The proprioceptive function receptors were found in all areas of TFC because Ruffini corpuscles have homogeneous distribution in this fibrocartilaginous tissue. CONCLUSIONS: Our results showed that the nerve endings were distributed at the periphery of TFC and showed different concentrations of each type of mechanoreceptors per topographic area, suggesting that they play specific roles in the proprioceptive and nociceptive reflexes of the wrist.