Effect of experimental subarachnoid hemorrhage on CSF eicosanoids in the rat

A simple and inexpensive experimental model of subarachnoid hemorrhage (SAH) was developed in the rat. Based on accumulating data indicating the important role of arachidonic acid metabolites in the etiology of delayed cerebral vasospasm, we investigated changes induced by SAH on cerebrospinal fluid (CSF) levels of prostaglandin E2 (PGE2), F2 alpha (PGF2 alpha), and thromboxane B2 (TXB2). SAH was produced by the cisternal injection of blood via percutaneous suboccipital puncture. SAH rats (n = 200) were injected with 300 microliters of fresh autologous arterial blood; Control rats (n = 100) received the same volume of mock CSF. In 60 additional animals, no injections were made. To follow the changes induced by SAH on both the spectrum and time course of CSF eicosanoids, cisternal CSF samples were collected under basal conditions, 6, 12, and 36 after cisternal injection. PGE2, PGF2 alpha, and TXB2 were assayed in aliquots of CSF obtained by pooling samples from each experimental group. Eicosanoids were assayed using radioimmunoassay techniques. Arterial spasm was verified in parallel groups of SAH and control rats by comparison of the angiographic diameters of the basilar arteries (BA) and middle cerebral arteries (MCA) to that of the stapedial artery. CSF levels of all three eicosanoids were significantly higher in the SAH groups compared to both noninjected and mock-CSF injected control rats. These increases in concentrations of eicosanoids were accompanied by a decrease in the mean vascular diameter (77.5-82.0% of control) on day 2 following cisternal injection. We conclude that marked elevations of spasmogenic eicosanoids in the CSF are associated with experimental SAH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental model of nervous anastomosis between intercostal and lumbar nerves in the rabbit

The authors propose a new experimental model of nervous anastomosis between intercostal and lumbar nerves in rabbit with the purpose of providing a technique to by-pass a spinal lesion. Before carrying out the surgical experiments, an histological study has been performed on the donor and receiver nerves which demonstrated the great difference in number of nervous fiber between these two nerves. The purpose of the method is thus to reinnerve a lumbar nerve by means of two intercostal nerves. Histological controls are performed on the 120th day.     

Copper-zinc superoxide dismutase activity in healthy and inflamed human dental pulp

AIM: To examine copper-zinc superoxide dismutase (Cu, Zn-SOD) activity in clinically healthy and symptomatic human dental pulps. METHODOLOGY: Twenty-five systemically healthy patients, 14 females and 11 males (age: 13.1-34.6 years; mean: 21.7 +/- 6.3), were the source of the pulp tissue. The condition of the pulps was assessed using clinical and radiographic evaluation. The pulp tissue was collected by longitudinally grooving and splitting the teeth (if extracted) or during endodontic treatment, and were age- and sex-matched between the healthy and the irreversible symptomatic pulpitis tissue groups. Cu, Zn-SOD activity was determined through spectrophotometric methods and a Mann-Whitney test assessed the significance of differences between the groups. RESULTS: The enzyme activities were 144.8 +/- 42.2 and 68.1 +/- 25.0 U mg(-1) in the healthy and irreversible symptomatic pulp tissue, respectively. The difference between the groups was statistically significant (P < 0.001). CONCLUSIONS: These results demonstrate a potential role for Cu, Zn-SOD during dental pulp inflammation in humans.     

Risultati clinici e istologici delle preparazioni subgengivali a lama di coltello. Casi clinici

Objectives

This article evaluates the correlation between clinical and histological results in teeth prepared for fixed prosthodontics using the Biologically Oriented Preparation Technique (BOPT).

Materials and methods

Clinical cases are presented to illustrate the main steps in the BOPT procedure and the clinical results. Six anterior teeth regarded as “hopeless” were used for histological analysis. Three were prepared according to the BOPT (test), and the other three were prepared with a rounded juxtagingival shoulder (control). Temporary acrylic resin restorations were immediately placed. The teeth were extracted after five weeks.

Results

The junctional epithelium (JE) measured 2.5 ± 0.4 mm (test) and 1.7 ± 0.3 mm (control) (p < 0.001). The area of connective tissue infiltrated by inflammatory cells was 2.7 ± 0.7 mm² (test) and 1.5 ± 0.3 mm² (control) (p < 0.001).

Conclusions

The BOPT appears to favor the formation of a long JE and inflammatory-cell infiltration of the connective tissue, so it should not be used on periodontically sound teeth.