Evaluation of Structural and Compositional Changes on the Root Surface Exposed to Diode Laser (810 nm): An In?vitro Study

Background: The laser therapy has been used as an adjuvant for conventional periodontal disease as they exhibit a bactericidal effect on scaling and root planning by its thermal and photo disruptive effects on the pathogens. This study focuses on the structural and compositional changes induced on the root surfaces of teeth following diode laser (DL) application with increasing quantum of exposure time. Objective: The objective of this study was to evaluate the structural and compositional changes on the root surface of extracted human permanent teeth after application of DLs (810 nm) with varying time interval. Materials and Methods: Twenty samples of single?rooted periodontally compromised extracted teeth were utilized for this study. Root planning was done and the roughness caused by the instrumentation was measured using profilometric analysis. Then, the samples were divided into four groups, with DL application time: Group 1 – laser application for 15 s, Group 2 – laser application for 30 s, Group 3 – laser application for 45 s, and Group 4 – laser application for 60 s. A scanning electron microscope was used to examine the cemental surface and energy?dispersive X?ray analysis software assesses the compositional changes of the teeth in each group. Results: This study reveals that on exposure of DL (810 nm) on the root surface when time of exposure increases, there were relative increases in surface irregularities and charring. There were significant changes in the chemical composition of the tooth surface.

Ultrastructural changes in the kidney cortex of rats treated with lead acetate / Cambios ultraestructurales en la corteza renal de ratas tratadas con acetato de plomo

The purpose of this study was to investigate the ultrastructural effects of lead on the kidney cortex of rats. Wistar Albino rats (180-200g body weight) were divided into a controlled and lead acetate-exposed group. Rats received lead acetate at 500 ppm in their drinking water for 60 days. Both groups were fed with the same standard food, but lead acetate was added to the drinking water. During the experimental period, blood samples were taken from the abdominal aorta of the anesthetised animals. At the end of exposure, body weight and blood lead levels were measured. The kidney tissue samples were prepared and analyzed by light and transmission electron microscopy. Cortical renal tubules show various degenerative changes with focal tubular necrosis invaded by inflammatory cells. The ultrastructural alterations found in lead acetate-treated rats were a diminution in the amount of filtration slits, increased fusion of foot processes in epithelial cells of the glomeruli, increase of lysosomal structures and pinocytic vesicles as well as large mitochondria in proximal tubule cells.

El propósito de este estudio fue investigar los efectos ultraestructurales del plomo en la corteza renal. Ratas Wistar albinas (180-200g de peso corporal) fueron divididas en grupo control y grupo experimental. Las ratas recibieron 500 ppm de acetato de plomo en el agua potable durante 60 días. Ambos grupos fueron alimentados con el mismo alimento estándar, pero acetato de plomo se le añadió al agua potable al grupo experimental. Durante el período experimental, se tomaron bajo anestesia muestras sanguíneas desde la parte abdominal de la aorta. Al final de la exposición, fueron medidos el peso corporal y los niveles de plomo en la sangre. Fueron preparadas las muestras de tejido renal y se analizaron mediante microscopía de luz y electrónica de transmisión. Los túbulos renales corticales mostraron varios cambios degenerativos con necrosis tubular focal invadida por células inflamatorias. Las alteraciones ultraestructurales encontradas en las ratas tratadas con acetato de plomo correspondieron a una disminución en la cantidad de ranuras de filtración, aumento de la fusión de los procesos podales en las células epiteliales de los glomérulos, aumento de la estructura lisosomal y las vesículas pinocíticas, así como grandes mitocondrias en las células del túbulo proximal.

Estudo clínico e ultraestrutural pós-turbinectomia inferior parcial / Clinical and ultrastructural study after partial inferior turbinectomy

O presente trabalho refere-se ao estudo dos resultados clínicos e histológicos obtidos após a turbinectomia inferior parcial (TIP), cirurgia indicada no tratamento da obstrução nasal crônica causada pela hipertrofia das conchas nasais inferiores. MATERIAL E MÉTODOS: Foram estudados vinte pacientes, divididos em dois grupos de dez cada (grupos A e B), submetidos à TIP, associada à septoplastia ou não. Os pacientes foram reavaliados clinicamente e histologicamente (com biópsia das áreas regeneradas das conchas inferiores), em dois períodos pós-operatórios diferentes: um grupo após oito a doze meses (grupo A) e outro após dois anos de TIP (grupo B). RESULTADOS: Os resultados clínicos mostraram-se satisfatórios para o alívio da obstrução nasal no grupo A, e insatisfatórios no grupo B. Entretanto, melhores resultados histológicos, com maior recuperação e diferenciação epitelial da mucosa regenerada das conchas inferiores após a TIP foram observados no grupo B, com sua ultraestrutura ciliar normal. CONCLUSÕES: A cirurgia revelou ser eficaz a curto, mas não em médio prazo, apesar da recuperação histológica ter sido importante.

We report clinical and histological results obtained after partial inferior turbinectomy (PIT), surgery indicated for the treatment of chronic nasal obstruction. METHODS: Twenty patients were divided into two groups submitted to PIT plus septoplasty and PIT alone. The patients were reassessed clinically and histologically by means of a biopsy of the regenerated areas in the inferior turbinates at two different times after PIT, i.e., after 8 to 12 months (group A) and after two years (group B). RESULTS: The clinical results proved to be satisfactory for the relief of nasal obstruction in group A and unsatisfactory in group B. However, better histological results with better recovery and epithelial differentiation of the regenerated mucosa of the inferior turbinates after PIT were observed in group B. CONCLUSION: Surgery proved to be effective on a short-term but not on a long-term basis, and histological recovery did not accompany improvement of clinical signs and symptoms.

Ultrastructural Changes of Myotendinous Nerve Endings following Recession or Resection Procedures of Extraocular Muscle Surgeries in Cats

To verify the postoperative ultrastructural changes of the myotendinous nerve endings of feline extraocular muscles, which are known as proprioceptors. Sixteen recti of four cats were used and divided into three groups. In group A, eight lateral recti were recessed. In group B, four medial recti were resected by 10 mm from insertion to include the myotendinous junction. In group C, four medial recti were resected by 4 mm of muscle bellies only, without disturbing the myotendinous junction. Four weeks after surgery, specimens were examined with electron microscopy. In group A, overall neural structures were well maintained with slight axonal degeneration. In group B, only muscle fibers were observed without any regeneration of neural sprouts. In group C, axonal disintegration and shrinkage were evident. These results indicate that myotendinous nerve endings can be damaged in strabismus surgery, and that resection was more invasive than recession in disrupting myotendinous nerve endings.

Expression of Vascular Endothelial Growth Factor after Laser Induced Retinal Vein Occlusion in the Rat Eye

PURPOSE: To examine the effects of retinal vein occlusion (RVO) on VEGF expression and the ultrastructural change of the various ocular tissues in the rat. METHODS: Sprauge Dawley rats were grouped into RVO group induced with argon laser (n=30) and control (n=10). The ocular tissues of the rats were collected on the first, third and seventh day after RVO. VEGF expression was evaluated with immunohistochemical stain, and the ultrastructural changes were observed with electron microscopy. RESULTS: In control group, VEGF stain was positive in various ocular tissues except outer nuclear cells. In RVO group, VEGF expression had gradual increase in the inner nuclear layer, the retinal pigment epithelia and the ciliary body epithelia after RVO. Especially, in the retinal pigment epithelia, VEGF was significantly increased on the seventh day. In electron microscopic examination, degenerative changes had gradual increase in the inner and middle retinal layers after RVO. The degenerative changes in the retinal pigment epithelia were noted on the third day, and in the retinal photoreceptor cells on the seventh day. CONCLUSIONS: These results showed that VEGF expressions in the inner nuclear layer, retinal pigment epithelia and ciliary body epithelia had a gradual increase, and the ischemic damages of the retina and the optic nerve progressed from the inner layer to the outer layer after RVO.

Ultrastructural changes of human testis after vasectomy / 대한비뇨기과학회지

Vasectomy is one of the most common forms of male contraception throughout the world. However, more vasectomy reversals are sought each year because of the increasing number of second marriages and other causes. Before recommending vasectomy, urologists may wish to resolve in their own mind the conflict between reports that maintain the testis is harmed by vasectomy and those that slate is not. We studied a group of patients undergoing vasectomy reversal to determine whether histopathologic change on light and electron microscopy would be detected. Only one testis specimen from post-vasectomy patients showed an abnormality correlated with spermatogenesis and five cases showed mild focal interstitial fibrosis without abnormality of spermatogenesis on light and electron microscopy. We found that vasectomy has some influence to the spermatogenesis and pathologic change.

Ultrastructural changes of cryptorchid testis / 대한비뇨기과학회지

Morphological studies have an important role in establishing the timing of irreversible damage occurred in cryptorchid testis. The present study was undertaken to determine how soon definitive sign or testis pathology may appear in cyptorchid testis. Testicular biopsies were collected at the time of orchiopexy from 79 patients during the period from January, 1988 to June, 1990, and then we examined ultrastructural changes of cryptorchid testis with light and electron microscopy. Comparing with normal testis, following results were obtained ; l. The volume of cryptorchid testis became smaller than normal after age of 14. 2. Mean tubular diameter became smaller after age of 14 and basement membrane thickened prominently after age of 20. 3. The increase number of mitochondria appeared at age of 2 4. Cytoplasmic vacuolization became prominent after age of 6, but detachment and loss of ribosome appeared at age of 20. 5. Tunica propria showed marked thickening and collagenous degeneration after age of 14. With above results, we suggest that orchiopexy should be done before age of 2.

Effect of Lysodren(R) on the Ultrastructural Changes in the Rat Adrenal Corex: Immunohistochemical staining for anti-ACTH antibody on the adenohypophysis

The toxicity and adrenostatic effect of o,p'-DDD, a derivative of the insecticidal DDT, on the adrenal cortex were well known. It known that the toxicity was based on the blocking of steroid biopsynthesis when cholesterol was converted to pregnenolone. Lysodren(R) was also known to be capable of producing a regression of adrenocortical carcinoma and its metastases, and this drug became one of useful choice for the treatment of unoperable adrenocortical carcinomas. Recently, fine structural effect of o,p'-DDD on the adrenocortical carcinoma show that the mitochondria is the primary target organelle. o,p'-DDD was dissolved in corn oil and it was orally administered for 28 days to investigate the ultrastructural effects of zona fasciculata of rat adrenal cortex. The results obtained were as follow: 1) The body weight was decreased after feeding o,p'-DDD. 2) Light microscopic examination showed no remarkable change except increased fine lipid droplets of zona fasciculata in group I (o,p'-DDD 75 mg/kg feeding). Moderately increased intracytoplasmic lipid droplets and pyknotic nuclei bearing membrane indentations were seen in group II (o,p'-DDD 150 mg/kg feeding). Large sized lipid droplet aggregates, pyknotic nuclei with severe nuclear membrane indentations and karyorrhexis in focal area were evident in group III. 3) Immunohistochemical staining for ACTH in pituitary gland showed increasing number of ACTH secretory cell and increasing intensity of staining property according to the dosage of o,p'-DDD. 4) Ultrastructural examination showed increased intracytoplasmic lipid droplets and mild increased peroxisome. There was no remarkable ultrastructural changes in mitochondria in group I. Moderately increased lipid droplets and clusters formation, compressed mitochondria, partial disappearance of mitochondrial cristae, increased peroxisome and nuclear membrane indentations were seen in group II. In group III, nuclear membrane showed prominent indentation. Numberous cytoplasmic vacuolation, double membrane ring in mitochondria, disappearance of mitochondrial cristae, myelin figure formation in mitochondrial matrix, and fatty changes in mitochondrial matrix were seen. These findings showed that the primary target organelle of attack by o,p'-DDD on zona fasciculata of adrenal gland in rat is mitochondria and it was developed from double ring formation in mitochondrial matrix.

PATHOLOGICAL CHANGES OF MYOCARDIUM OF THE EXPERIMENTAL RABBITS BLEEDING TO DEATH AND SHOCK / 中国法医学杂志

Transmission electron microscopy, histochemstry, immunohistochemistry and morphometry were used to study ultrastructural changes, succinic dehydrogenase (SDH) activity and myoglobin (Mb )content of the rabbit's myocardium bleeding to death and to hemorrhagic shock. The results were as follows: the myocardium showed different degrees of ultrastructural changes; various degrees of decreasing of SDH activity and deletion of Mb. These changes gradually become more serious with lapse of time after shock. The mechanism of the changes and the significance in forensic medicine are discussed.

The effects of PLC on the ultrastructure of platelets / 中国药理学通报

AIM To investigate the effects of PLC on ultrastructure of platelets. METHODS The effects of PLC on ADP induced platelet aggre-gation were detected by tubidmetry; the ultrastru-cture changes of platelet were analyzed by electron microscope. RESULTS The rate of PLC inhibited significantly platelet aggregation by ADP induced is 86 03%?12 06% and 82 47%?5 49%. Pseudopodia can inhibit by 0 5 U PLC, at this group increase in the number of the granules associated with enhanced intensities of their electron densities and smaller dilated canalicular system. compared with normal saline group. In the 2 5 U PLC group the platelet morphology and ultrastructure approach blank group. The platelet is very smooth. PLC can inhibit producing pseudopodia-like process and the releasing of granules. Dilated canalicular system is similar to blank group, But it was different to normal group. CONCLUSION It's showed that PLC can significantly inhibit platelet aggregation and ultrastructural changes.

Ultrastructural Changes in the Spiral Organ of Cochlea after Exposure to Impulse Noise / 第二军医大学学报

Ultrastructural changes in the spiral organ of cochlea at various intervals after exposure to impulse noise were investigated. Guinea pigs were exposed to 10 impulses noise of 166 dB SPL peak level which had duration of 0.1 ms. Thirteen of the exposed animals were used to systematically measure threshold shift at regular intervals from 30 min to 30d post-exposure. The other fourteen animals who had been exposed to the same impulse noise were killed for transmission electron microscopy (TEM) examination at the same intervals, respectively. The recovery pattern of threshold shift showed a nonmonotonic type. There was a progressive deterioration of changes in the hair cells between 30 min and 8h after exposure. Intracellular degeneration reached a peak at 8h and marked edema and swelling leading to deformation of the outer hair cells (OHCs), fused stereocilia, large vesicles in cytoplasm and swollen submembraneous cisterns were found. After that time the extent of degeneration in the hair cells reduced. The time sequence of changes in the spiral organ of cochlea in the present study was associated with the recovery pattern of threshold shift.

A MORPHOLOGICAL STUDY ON THE NEURAL TUBE DEFECTS INDUCED BY BIS-A-TDA / 解剖学报

30 sexually mature, virgin female SD rats, weighed 200-270 g were mated and used for the study of the teratogenic effect of N, N-methylene-bis (2-amino-1,3,4-thiadiazole) (Bis-A-TDA) on fetal neural tube formation and to explore the possible morphological mechanism of neural tube defects (NTD). In the morning of day 10 of gestation, the experimental group was administered with 10mg/kg body weight Bis-A-TDA mixed in peanut oil, and the control group with the same amount of peanut oil only. The results Showed that the incidence of NTD was 52.9% and the majority of NTD were excencephaly and encephalocele in the experimental group. In the early stage of NTD formation, some neuroepithelial cells showed vacuolated degeneration and necrosis, and the mitochondria became swollen and with indistinct or even disappeared crista. The intercellular spaces widened, and some cells escaped into the lumen of neural tube. The mitotic index of neuroepitbelial cells were sharply decreased. In the closure region of the telencephalon, similar changes of the neuroepithelium were present also, and decreased migration of mesodermal cells was noted. We consider the failure of cranial neural folds to approximate and closure was caused mainly by the damage of neuroepithelial cells, inhibition of cell proliferation, alteration of intercellular junctions and the changes of topographical arrangement of the neuroepithelium. The damage and delayed migration of mesodermal cells might also be involved in this event.

ULTRASTRUCTURAL STUDIES OF THE INJURIOUS ACTION OF CADMIUM AND PROTECTIVE ACTION OF ZINC ON RAT TESTIS / 解剖学报

This paper presents the ultrastructural studies of the immediate and delayed effects of Cadmium (Cd) on rat testes and the protective effects of Zinc (Zn) on Cd induced injury. Forty-two rats were divided into three groups: 1) treatment with Cd (2mg/kg body weight); 2) treatment with Cd combined with Zn (80mg/kg body weight); and 3) the controls.The ultrastructural changes of some spermatids, spermatogonia primary spermatocytes and peritubular tissue were detected within 10—30 minutes after Cd treatment. The morphlogical alterations of spermatids and primary spermatocytes appeared first. However, after 1 hour, the changes of testicular capillaries were observed, and those of the Leydig cells were found within 2—4 hours. After 3—7 days, the seminiferous epitheium, peritubular tissue and interstitial tissue were totally necrosed. These results suggest that both seminiferous tubules and testicular capillaries are damaged directly by Cd treatment, but the ultrastructural alterations of the capillaries appear later than those of the seminiferous tubules. The protective effect of Zn on the testicular injury induced by Cd is prominent. However, this effect on the early spermatids is weaker than that on the other germ cells.