Biological stability and osteoconductivity in rabbit tibia of pulsed laser deposited hydroxylapatite coatings.

A comparative study of the biological stability and the osteoconductivity of hydroxylapatite (HA) coatings produced by pulsed laser deposition (PLD) and plasma spraying (PS) was conducted. Three different implant groups were used: grit-blasted titanium rods coated with HA-PLD (2-microm-thick), grit-blasted titanium rods coated with HA-PS (50-microm-thick), and uncoated. Implantation took place into the proximal tibia of 12 mature New Zealand White rabbits for 24 weeks. Samples were evaluated using descriptive histology and histomorphometry. While HA-PS implants showed considerable instability and reduction in thickness after 24 weeks, but no statistical difference to the titanium group, the HA-PLD group showed a significant higher amount of bone apposition (Scheffé test, p<0.05) than the other two groups, without signs of degradation or dissolution. Remarkably, after 6 months, the almost intact thin pulsed laser deposited coating could be observed by electron microscopy in extended areas.

Intestinal ulcerogenic effect of S(+)-ketoprofen in the rat.

Nonsteroidal antiinflammatory drugs (NSAIDs) inhibit prostaglandin synthesis in the gastrointestinal mucosa, which can lead not only to stomach ulcers but also ulcers in the small and large intestines. Ulcers of the small intestine are less common than those of the stomach, but intestinal lesions are more life threatening. Although the R(-)-enantiomers of the arylpropionic acid (APA) class of NSAIDs are assumed to lack the toxic effects of cyclooxygenase inhibition, they may contribute to the ulcerogenicity of racemates. We have examined the intestinal ulcerogenic effects of single oral doses of S(+)-ketoprofen compared with racemic ketoprofen in the small intestine and cecum of rats. The toxicity in the small intestine was measured as the weight ratio between portions of intestine showing lesions and the total weight of the tissue. Toxicity in the cecum was evaluated by measuring the size of the ulcers. S(+)-ketoprofen had no significant ulcerogenic effect at 10 or 20 mg/kg. However, racemic ketoprofen was clearly ulcerogenic in the small intestine and cecum at the 40 mg dose. R(-)-ketoprofen at 20 mg/kg does not show any effect in the cecum and only limited ulcerogenesis in the small intestine: The latter effect may be the result of racemic inversion. Therefore, the ulcerogenic action of racemic ketoprofen can be interpreted as a synergism between S(+)- and R(-)-ketoprofen. The mechanism of this synergism is not well understood but may be a general feature of APA NSAIDs.

Comparison of the anti-inflammatory effect and gastrointestinal tolerability of aceclofenac and diclofenac.

Aceclofenac (CAS 89796-99-6) and diclofenac (CAS 15307-79-6) are orally effective non-steroidal anti-inflammatory drugs. Their anti-inflammatory and potential gastrointestinal damaging effects were compared following single and repeated administration (5 days). Both drugs exerted an anti-inflammatory activity and showed a similar gastrointestinal tolerability in the rat.

[Leiomyosarcoma of the spermatic cord]. / Leiomiosarcoma de cordón espermático.

Presentation of an uncommon paratesticular tumour, located in the spermatic cord and originated in the smooth muscle of the cremaster, deferent, or the cord's vascular structures. In 1966, KYLE in Canada reviewed 22 cases of paratesticular leiomyosarcoma from the English literature, and in 1984 PUTS in the Netherlands extended this catalogue to 39. TAKAHA in 1991 presented 18 cases found in the Japanese literature. The theory of malignant degeneration from a previously existing leiomyomatous tumour is generally accepted. This entity is clinically associated with a clear tendency to local relapse, which does not imply a worse prognosis, and with a high percentage of blood metastasis three years after exeresis. The choice therapy is oncologic inguinal orchiectomy. Radiotherapy and chemotherapy, as coadjuvant therapies, appeared to be more effective in children's than in adult's sarcoma. Prognosis of these neoplasias in the reviewed literature is highly variable, ranging between 10% and 62% survival at 5 years, possibly due to the diversity of therapies and the patient's stage at the time of diagnosis.

Diuretic effect of ITA 529.

The diuretic and saluretic activity of ITA 529 (Ethyl-beta-[(5-tert-butyl-3-chloro-2-hydroxy)benzylamino]crotonate++ +) in rat, rabbit and monkey is described in this study. In rat, the diuretic ED50 of ITA 529 was 1.23 mg/kg p.o. and its ED100 1.69 mg/kg p.o. The diuretic ED50 of furosemide was 18.48 mg/kg p.o. and its ED100 22.38 mg/kg p.o. Their effect lasted approximately 3 hours. In monkey, the diuretic ED50 of ITA 529 was 2.29 mg/kg p.o. and its ED100 6.54 mg/kg p.o. while for furosemide its ED50 was 2.44 mg/kg p.o. and its ED100 5.72 mg/kg p.o. In rabbit the ED50 of ITA 529 was 1.83 mg/kg p.o. and its ED100 3.37 mg/kg p.o. For furosemide, its ED50 was 2.25 mg/kg p.o. and its ED100 7.13 mg/kg p.o. The natriuretic activity of ITA 529 was reduced by indomethacin.

Endothelial damage induced by polyethylene catheter in rat.

A method is described for obtaining endothelial lesions in the aorta by implanting polyethylene catheters in the aorta of rats for two days. Three types of lesions were observed and were quantified by measuring their lengths: (a) the simple disendothelization (b) raised lesions, and (c) tunnel lesions. The effect of a number of antiplatelet drugs on these types of lesions was investigated, and it was observed that these are particularly active in inhibiting tunnel lesions. Using this method, endothelial lesions can be obtained in a short period of time. Moreover, a large number of results can be obtained rapidly, which is important in these types of experiments due to the high dispersion obtained.