In vivo bone tissue response to a canasite glass-ceramic.

The aim of this study was to determine the biocompatibility and osteoconductive potential of a high-strength canasite glass ceramic. Glass-ceramic rods were produced using the lost-wax casting technique and implanted in the mid-shafts rabbit femurs. Implants were harvested at 4, 13 and 22 weeks and prepared for light and electron microscopy. Hydroxyapatite was used as a control material. Hydroxyapatite implants were surrounded by new mineralised bone tissue after 4 weeks of implantation. The amount of bone surrounding the implant increased slightly at 13 weeks. In contrast, canasite glass and glass ceramic implants were almost entirely surrounded by soft tissue during all the time periods. Close contact between bone and canasite glass-ceramic implant without the intervening fibrous tissue was observed in only a few regions. The canasite formulation evaluated was not osteoconductive and appeared to degrade in the biological environment. It was therefore concluded that the canasite formulation used was unsuitable for use as implant. Further work is required to improve the biocompatibility of these materials with bone tissue. It is possible that this could be achieved by reducing the solubility of the glass and glass ceramic.

[Effect of antiseptic treatment of alveolar surgical wounds on bacterial growth on cotton suture threads]. / Efeito da anti-sepsia da ferida cirúrgica alveolar sobre o crescimento bacteriano em fios de sutura de algodão.

The objective of this study was to evaluate bacterial growth on cotton suture. The efficiency of cetylpyridinium chloride (50%), hydrogen peroxide (3%) and chlorhexidine (0.12%) in antisepsis was investigated. For that, 20 patients who were submitted to extraction of impacted lower third molars were studied. Five days after extraction, samples were obtained from the oral and alveolar sides of the sutures, before and after antisepsis of the wounds, and were submitted to bacteriological analysis. Bacterial growth was observed in all examined samples. The number of streptococci decreased after antisepsis and there were no statistically significant differences between the methods of antisepsis used.

Complex treatment of dens invaginatus type III in maxillary lateral incisor.

The complex anatomy and diagnosis of dens invaginatus make endodontic treatment of such teeth difficult. This case describes combined nonsurgical and surgical treatment of a maxillary lateral incisor with a normally shaped canal and a dens invaginatus type III with a lateroradicular lesion. The root canal was treated conventionally with gutta-percha and a zinc oxide-eugenol sealer. The root was surgically exposed and the canal of the dens invaginatus was cleaned, instrumented and obturated with gutta-percha and a zinc oxide-eugenol sealer. At follow-up 3 years 6 months later, the tooth was asymptomatic and radiographically showed repair of the lesion in the region of the dens invaginatus.

Locus ceruleus lesions block pulsatile LH release in ovariectomized rats.

Luteinizing hormone (LH) secretion during the reproductive cycle and in ovariectomized (OVX) rats is pulsatile and this pattern of secretion is determined by intermittent discharges of LH-releasing hormone (LHRH) into the hypophysial portal vessels. LHRH secretion is probably controlled by prior pulsatile norepinephrine (NE) release. The locus ceruleus (LC) is an important source of NE to the LHRH neurons. We have shown previously that LC lesions block the preovulatory LH surge and ovulation and also cause a decrease in plasma LH concentrations in OVX rats. The possible role of the LC in regulating pulsatile LH release has not been explored. Therefore, the aim of this work was to investigate, in OVX rats, the effects of LC lesions on pulsatile LH secretion. LC lesions were produced in adult female rats three weeks after OVX. On the next morning, the jugular vein was catheterized and, on the afternoon of the same day, blood samples (0.3 ml) were withdrawn every 5 min, during 90 min, from conscious freely moving rats. Plasma LH was measured by radioimmunoassay. LC lesions greatly suppressed pulsatile LH secretion by decreasing both LH pulse frequency and amplitude. The basal as well as total secretion of LH were also decreased. This inhibitory effect of the lesions was observed only when at least 50% of the nucleus was destroyed. Data from sham-operated animals as well as those with less than 50% destruction of the LC did not differ from those of the control rats without brain lesions. Since LC lesions induce a decrease in NE content in the preoptic area and median eminence, the inhibition of pulsatile LH release in ovariectomized rats with LC lesions occurs presumably as result of decreased pulsatile NE release into these areas of the brain that decreases both the frequency and the amount of LHRH released per pulse.

C-fos expression and electrolytic lesions studies reveal activation of the posterior region of locus coeruleus during hemorrhage induced hypotension.

Bilateral electrolytic lesions in the rat Locus Coeruleus (LC) were made one or seven days before experimentation. Four hemorrhage sessions, withdrawing 10% of the blood volume per session, were performed in 5 min intervals in freely moving rats. Blood pressure (BP) was not affected by the lesions and did not drop in the first, but decreased in all subsequent hemorrhages. The decrease in BP in animals with lesion in the anterior LC was similar to the controls. However, animals with lesions in the posterior LC showed an enhanced decrease in BP during the second hemorrhage, in acute and chronic experiments. Expression of Fos protein was studied to investigate the relationship between LC activity and BP changes. Two hours after the second hemorrhage, the brains were removed and processed for Fos immunocytochemistry. Hemorrhage increased the number of Fos immunoreactive neurons mainly in the posterior LC. We conclude that (1) the LC does may not play a role in cardiovascular control during resting, but seems to mediate compensatory cardiovascular mechanisms in situations of hypovolemia; and (2) the posterior LC, but not the anterior, plays a pressor role during hemorrhage.

Hidatidosis hepática: estudio descriptivo de algunos aspectos clínicos y terapéuticos / Hepatic hydatidosis: descriptive study of some clinical and therapeutical aspects

La hidatidosis constituye una zoonosis de importancia en Chile, su frecuencia es mayor en aquellas regiones donde es importante la actividad agrícola y ganadera. La localización hepática de la enfermedad es la más común y se relaciona con una incidencia significativa de complicaciones y mortalidad. La ultrasonografía es una técnica de alto rendimiento en su diagnóstico. Se efectúa un análisis retrospectivo de 105 pacientes con diagnóstico de hidatidosis hepática (HH), portadores de 187 quistes, atendidos en el Servicio de Cirugía y Unidad de Emergencia del Hospital Regional de Temuco, entre enero de 1993 y mayo de 1995. En ellos se analizó: cuadro clínico, laboratorio general, de función hepática, inmunoloïgía, radiografía de tórax y ecotomografía abdominal. Se efectuaron técnicas conservadoras de 63 casos (60,4 por ciento) y resectivas en 42 casos (39,6 por ciento); 34 individuos (32 por ciento) presentaban quistes complicados, y no se alcanzó significancia estadística al comparar el tipo de quiste con la complicación de éste. La morbilidad global de la serie fue 20,9 por ciento, hubo diferencias significativas al analizar la morbilidad postoperatoria con la complicación del quiste (p = 0,048), donde se observa que los quistes complicados presentan mayor incidencia de morbilidad posterior a la cirugía . La letalidad de la serie es de 0 por ciento

Effect of intracerebroventricular injection of ramipril on the drinking response caused by injection of noradrenaline into the third ventricle.

We studied the effect of ramipril injected into the third ventricle (3rdV) on the control of water intake induced by injection of noradrenaline into the 3rdV of adult male Holtzman rats (250-300 g) implanted with a chronic stainless steel cannula into the 3rdV. The injection volume was always 1 microliter and was injected over a period of 30-60 sec. Control animals were injected with 0.15 M NaCl. After the injection of isotonic saline (control, 0.15 M NaCl) into the 3rdV, water ingestion was 0.3 +/- 0.1 ml/h. Ramipril (1 mircogram/microliter) injected into the 3rdV prior to isotonic saline produced no changes in water ingestion (0.4 +/- 0.2 ml/h). The injection of noradrenaline (40 nmol/microliter) after isotonic saline induced an increase in water intake (3.0 +/- 1.1 ml/h). The prior injection of ramipril decreased this ingestion to 1.8 +/- 0.3 ml/h. These data show that the inhibition of converting enzyme in the brain reduces the water intake induced by catecholaminergic stimulation. We conclude that the brain is able to transform the prodrug ramipril into the active drug ramiprilat.

Effect of intracerebroventricular injection of ramipril on the drinking response caused by injection of noradrenaline into the third ventricle

We studied the effect of ramipril injected into the third ventricle (3rdV) on the control of water intake induced by injection of noradrenaline into the 3rdV of adult male Holtzman rats (250-300 g) implanted with a chronic stainless steel cannula into the 3rdV. The injection volume was always 1mul and was injected over a period of 30-60 sec. Control animals were injected with 0.15 M NaCl. After the injection of isotonic saline (control, O.15 M NaCl) into the 3rdV, water ingestion was 0.3 ñ 0.1 ml/h. Ramipril(l mug/mul)injected into the 3rdV prior to isotonic saline produced no changes in water ingestion (0.4 ñ 0.2 ml/h). The injection of noradrenaline (40 nmol/mul) after isotonic saline induced an increase in water intake (3.0 ñ 1.1 ml/h). The prior injection of ramipril decreased this ingestion to 1.8 + 0.3 ml/ h. These data show that the inhibition of converting enzyme in the brain reduces the water intake induced by catecholaminergic stimulation. We conclude that the brain is able to transform the prodrug ramipril into the active drug ramiprilat.

Complications in exodontia--accidental dislodgment to adjacent anatomical areas.

The authors report 4 cases of accidental dislodgement of teeth to adjacent anatomical areas during extraction. The causes and their prevention are discussed and solutions for the problem are suggested.

[Clinical evaluation of some splinting methods used for reimplantation and autogenous tooth transplants]. / Avaliação clínica de alguns métodos de contenção empregados em reimplantes e em transplantes dentais autógenos.

The aim of the present study was to evaluate and discuss the indications of different splinting methods used in surgical procedures. It was proposed that the use of "semirigid" fixation method could be a more valuable technique in autogenous transplants and dental reimplants.

Evaluation of pain and swelling after impacted third molar surgery.

The pain and swelling resulting from impacted lower third molars surgery were investigated in 18 patients. A descriptive pain scale method and paracetamol consumption were used for pain evaluation. The face bow nine-pointers was used for swelling measurements. The results showed that the pain peaked at 3 post-operative hours when it was considered of moderate intensity and decreased considerably in the following periods. Swelling peaked between 32 and 48 hours after surgery, and thereafter, a tendency towards regression was observed. No corelationship was found between pain symptoms and swelling.