Subsidence and its effect on the anterior plate stabilization in the course of cervical spondylodesis. Part I: definition and review of literature

A definition of subsidence in terms of spinal biomechanics is presented in the paper. Subsidence is defined as sinking of a body with a higher elasticity modulus (e.g. graft, cage, spacer) in a body characterized by a lower elasticity modulus (e.g. vertebral body), resulting in 3D changes of the spinal geometry. Magnitude of subsidence is directly proportional to the load pressure and to the difference between the elasticity modules, but inversely proportional to the area of the graft-bed interface. Both biological and mechanical qualities of the graft-bed interface are important for the subsidence process. Any excessive subsidence decreases the interbody space and produces both local and general kyphotization of the spine. This may cause destabilization of the screw-plate and/or screw-bone interfaces (e.g. pulling-out, altered angulation or breakage of the screws). A method is proposed of radiological estimating the absolute magnitude of subsidence, based on the real known length of the implanted stabilizer (e.g. plate). Clinical examples of an excessive subsidence and its impact on the stabilizing plate system are presented. Subsidence is inherent in the interbody fusion process. Endplate preservation and a dynamic modification of cervical plates may enables us to control subsidence and reduce the number of complications.     

Expression P53 protein and chromosome aberrations in benign tumors and ovarian carcinoma

OBJECTIVES: The epithelial ovarian tumors arise from the single layer of epithelial cells that line the ovarian surface or from underlying inclusion cysts. One from many theories of oncogenesis has been proposed that benign, borderline and invasive tumors represent sequential stages in the growth of an ovarian cancer, and p53 tumor suppressor gene mutation is the most common molecular genetic alteration. Because locus of p53 gene is located on 17 chromosome we performed the cytogenic analysis of tumor tissues. DESIGN: Analysis of mutated p53 protein expression and chromosomal aberrations in tissues of benign tumors and epithelial ovarian carcinomas. MATERIAL AND METHODS: Tissue samples from 19 women with benign and 17 women with invasive epithelial ovarian cancers were obtained for the study at the time of surgical procedures. From among benign tumors 12 were serous cystadenomas, 5 were endometrial cysts and 2 adult teratomas. All cases of invasive epithelial ovarian carcinomas were histologically recognized as serous adenocarcinomas, and were staged on I (9 cases), II (5 cases) and III (3 cases), according to the FIGO guidelines for ovarian cancers. Frozen tissue samples were stained immunohistochemically for mutated p53 protein using commercial monoclonal antibodies and standard detecting system. The fresh tumor samples were prepared for cytogenic analysis according to standard protocol. RESULTS: Among the all benign ovarian tumors overexpression of mutated form of p53 protein was not seen in any cases, but was noted in 6 cases in I stage and in all cases in II and III stages of advanced ovarian cancers. In 1 case of benign ovarian tumor deletion of X chromosome was observed. Most common numerical changes were observed in ovarian carcinomas e.g. loss of 8, 13, 17, and 22 chromosomes. Other chromosomes were involved at least once in structural rearrangements and several breakpoint cluster regions were identified: 19p13, 11p13-15, 1q21-23, 1p36, 19q13, and 6q21-23. CONCLUSIONS: The mutated form of p53 protein is often expressed in ovarian epithelial carcinoma tissues. This protein are unable to function effectively to inhibit proliferation and accumulate in the cells because is resistant to degradation. In tissues of ovarian carcinomas many chromosomal nondisjunctions (monosomics) and multiple structural rearrangements were observed, what means of genetically nonstable cell lines of neoplasms and probably it heterogenous origin.     

Strategies for fertility preservation after anti-cancer therapy

A tremendous advance in the field of cancer therapy resulted in a substantial improvement of long-term survival of oncological patients. The most frequent side effect of either chemotherapy or radiotherapy is a partial or complete lost of fertility potential. This paper reviews current knowledge on the fertility preservation strategies for patients facing oncological problems and the risks of iatrogenic infertility. The cryopreservation of spermatozoa or testicular tissue combined with assisted reproductive technology is the optimal solution for male patients. In the case of female patients, the use of ovarian transposition, ovarian suppression and ovarian tissue cryopreservation seem to be the valuable options for fertility prevention. The cryopreservation of embryos is another possible solution, although this procedure is only limited to the couples. On the other hand, there are still controversies regarding the ethical issues concerning gametes and embryos banking.     

New potent sensitizers for photodynamic therapy: 21-oxaporphyrin, 21-thiaporphyrin and 21,23-dithiaporphyrin induce extensive tumor necrosis

New sensitizers for photodynamic therapy (PDT) are reported. These compounds, namely 21-thiaporphyrin, 21,23-dithiaporphyrin and 21-oxaporphyrin, reveal some of the properties required for such therapy. Their physicochemical, chemical and pharmacological features meant that we could use them in the treatment of transplantable BFS1 fibrosarcoma in Balb/c mice. New sensitizers and the well-known chlorin e6 (Ce6) were used in doses of 2.5, 5.0, 7.5 and 10.0 mg/kg body weight, given intraperitoneally and followed by light irradiation, the total light doses being 50, 100 and 150 J/cm² within 24 h after injection. The effectiveness of new sensitizers in PDT was evaluated with in terms of tumor necrosis intensity, the survival time of treated animals, the rate of tumor response (complete/partial/no response), and skin photosensitivity. These results were compared to results obtained in analogous conditions after Ce6-PDT. Distribution studies revealed that the highest concentration of new compounds occurred within 24 h after injection. The results of these experiments confirmed that 21-thiaporphyrin, 21,23-dithiaporphyrin and 21-oxaporphyrin can be considered as potent tumor photosensitizers that do not exert any unwanted effects, primarily skin photosensitization. We suggest that these porphyrins are possible sensitizers to be applied in clinical PDT. Received: 17 December 1998 / Accepted: 12 April 1999     

Estimation of motor ranges and muscle strength in cervical spine after total laryngectomy

After total laryngectomy and after complementary treatment (radiotherapy) there are many functional disorders in the range of head and neck. It was observed, that muscles of this area became weakened with simultaneous increase of their rest tension. These changes affect reduction of physiological motor range of the cervical spine. Comparison of function of cervical muscle between patients after total laryngectomy and healthy people allows to characterize defects of neck movements. Detailed estimation of muscle strength and move range in cervical spine after total laryngectomy will enable application of effective physiotherapy program.     

Liver dysfunction in severe ovarian hyperstimulation syndrome.

We report the case of a 32-year-old woman suffering from severe liver dysfunction in the course of ovarian hyperstimulation syndrome (OHSS). Complications occurred after successful fertilization subsequent to ovarian stimulation with human menopausal gonadotropin followed by ovulation induction with human chorionic gonadotropin. Because of nausea, vomiting, abdominal distention and enlarged ovaries on an ultrasound examination, she was admitted on the diagnosis of OHSS. During the course of hospitalization severe hepatic injury developed. An increase of more than 100-fold in blood aminotransferase activity was observed. Applied treatment resulted in gradual reduction of ovarian size and resolution of ascites, as well as pleural and pericardial effusions. The patient was discharged from hospital after 46 days. Follow-up examinations at the 13th and 32nd weeks of gestation did not reveal any abnormalities. Pregnancy developed without complications and the woman went into spontaneous labor, giving birth to a viable child at 38 weeks' gestation. Taking into account the above case and previously published reports, the issue of liver dysfunction may have a great impact on the understanding both the pathology and the treatment of OHSS.     

Dyphenylhydantoin enhancement of diazepam effects on locomotor activity in mice

The interaction of diazepam and diphenylhydantoin on locomotor activity and rearing behavior was studied in mice. Pretreatment of mice with diphenylhydantoin (4.0 and 8.0 mg/kg) significantly reversed the stimulatory effects of low doses of diazepam and considerably increased the depressant effects of the benzodiazepine on locomotor activity and rearing. Neither diazepam (up to 4.0 mg/kg), diphenylhydantoin (8.0 mg/kg) alone, nor combined treatment with both drugs affected brain GABA levels and glutamic acid decarboxylase (GAD) activity at any dosage used. The present behavioral and biochemical data suggests that some of the pharmacological effects of diazepam need not be related to GABAergic mechanisms.     

Liver dysfunction in severe ovarian hyperstimulation syndrome

We report the case of a 32-year-old woman suffering from severe liver dysfunction in the course of ovarian hyperstimulation syndrome (OHSS). Complications occurred after successful fertilization subsequent to ovarian stimulation with human menopausal gonadotropin followed by ovulation induction with human chorionic gonadotropin. Because of nausea, vomiting, abdominal distention and enlarged ovaries on an ultrasound examination, she was admitted on the diagnosis of OHSS. During the course of hospitalization severe hepatic injury developed. An increase of more than 100-fold in blood aminotransferase activity was observed. Applied treatment resulted in gradual reduction of ovarian size and resolution of ascites, as well as pleural and pericardial effusions. The patient was discharged from hospital after 46 days. Follow-up examinations at the 13th and 32nd weeks of gestation did not reveal any abnormalities. Pregnancy developed without complications and the woman went into spontaneous labor, giving birth to a viable child at 38 weeks' gestation. Taking into account the above case and previously published reports, the issue of liver dysfunction may have a great impact on the understanding both the pathology and the treatment of OHSS.     

Effects of morphine and nalorphine on kainic acid-induced hypothermia in rats

Intraventricular administration of kainic acid at the dose of 0.1 g induces a significant depression of rectal temperature followed rapidly by its slight elevation. Morphine (40.0 mg·kg^-1 IP), which by itself elicited biphasic effect on the body temperature of rats—initially hypothermia followed by hyperthermia—slightly increased the kainic acid-induced hypothermia. Kainic acid did not cause any changes in the hyperthermic effect of low doses of morphine (10.0 mg·kg^-1). Pretreatment of rats with nalorphine enhanced the kainic acid-induced hypothermia. On the contrary, nalorphine reversed the hypothermic effect produced by morphine at the dose of 40.0 mg·kg^-1. The results suggest that morphine and kainic acid-induced hypothermia are not mediated by the influence on the same type of receptors.