Effects of angle and laminectomy on triangulated pedicle screws

We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine whether a 90 degrees screw angle is optimal as has been previously suggested. According to the angle between right and left screws, 28 calf vertebrae were divided into three groups and instrumented as follows: Group I: 60 degrees screw angle; Group II: 90 degrees angle; Group III: 60 degrees angle with laminectomy. The screws were connected using rods and cross-fixators and tested to peak pullout force. Triangulated pedicle screws provided 76.5% more pullout strength than single screws. Most of the specimens failed through loss of convergence angle (toggling of screws on the rods) and subsequent uni- or bilateral screw pullout. Mean+/-SD peak loads were: Group I: 2071+/-622 N; Group II: 1753+/-497 N; Group III: 2186+/-587 N. The differences were not significant (p>0.05). 90 degrees triangulation was not associated with a superior pullout performance versus conventional 60 degrees triangulation, suggesting that achieving additional triangulation angle is not necessary to obtain increased pullout strength. Laminectomy did not alter the effect of triangulation on fixation strength.     

Anti-cancer effect of metformin on the metastasis and invasion of primary breast cancer cells through mediating NF-kB activity

Current evidence strongly suggests that aberrant activation of the nuclear factor kappa B (NF-kB) signaling cascade is connected to carcinogenesis. The matrix metalloproteinases (MMP) which are also the key agents for tumor metastasis may be potent candidates for tumor diagnosis in clinics. In this in vitro study, we hypothesized that metformin with an effective dose can inhibit tumor cell proliferation and metastasis by modulating the expressions of MMP-2 and -9 and interfering with NF-kB signaling in primary breast cancer cells (PBCCs). 300 000 cells per ml were obtained from biopsies of breast tumors from five human donors. The cell viability and proliferation were tested. Immunocytochemistry was performed for MMP-2, MMP-9, and NF-kB, and enzyme-linked immunosorbent assay for NF-kB activity, quantitative real-time PCR for RELA/p65, IkBα, MMP-2, and MMP-9. Three different doses of metformin (5, 10, and 25 mM) (Met) reduced the viability and proliferation of PBCCs in a dose-dependent manner, maximum inhibition was observed at 25 mM Met. The expression of RELA/p65 was not affected by 25 mM Met. Nuclear immunoreactivity and activity of NF-kB reduced while cytoplasmic NF-kB (p65) elevated by 25 mM Met compared to non-treatment (P < 0.05). The expression and immunoreactivity of MMP-9 but not MMP-2 were decreased by 25 mM Met treatment, compared with the non-treatment (P < 0.05). Metformin may have an essential antitumor role in the invasion and metastasis pathways of PBCCs by downregulating the MMP-9 expression blocking both the activity and nuclear translocation of NF-kB.     

Serum leptin levels in gastric cancer patients and the relationship with insulin resistance

Introduction

Serum leptin levels have been examined in various cancers, with conflicting results. However, there is limited information regarding serum leptin levels and insulin resistance in gastric cancer patients. Therefore, we aimed to investigate serum leptin levels, performance status, insulin levels and insulin resistance in patients with gastric cancer. In addition, we examined the relationship between these measurements and leptin levels.

Material and methods

Thirty-nine patients with gastric cancer and 30 control subjects were enrolled in the study. Serum leptin, total protein, albumin, growth hormone, insulin and glucose levels were measured. The homeostasis model assessment (HOMA) was used to assess insulin resistance.

Results

Serum levels of insulin, glucose and growth hormone and insulin resistance were significantly lower in gastric cancer patients than controls (p < 0.05 for all). In the Pearson correlation analysis, insulin resistance was found to be significantly correlated with serum leptin levels in gastric cancer patients (r = 0.320, p = 0.047). We observed a significant negative correlation between performance status and insulin resistance in patients with cachexia (r = –0.512, p = 0.030), while no association was found in non-cachectic patients.

Conclusions

We concluded that serum leptin levels are significantly lower in gastric cancer patients. In addition, gastric cancer patients have decreases in insulin levels, insulin resistance and growth hormone levels. This study found a positive association between serum leptin levels and insulin resistance. Moreover, there is a negative association between serum leptin levels and growth hormone levels. Thus, low insulin and growth hormone levels may suppress the production of leptin in gastric cancer patients.     

Negative serology: could exclude the diagnosis of brucellosis?

Two cases of brucellar spondylodiscitis of the lumbar area were presented. Although both cases showed typical radiological changes, serological tests could not detect Brucella agglutinating antibodies. One of the patients was bacteremic and Brucella spp. was identified from blood culture. In the second patient needle biopsy was required for definite diagnosis. Although small, serologic tests have a certain rate of false negative results in brucellosis. Thus, a negative serology should not exclude the diagnosis of brucellosis, as it is demonstrated in the current cases.     

The Case of Acute Appendicitis and Appendiceal Duplication

Background: Appendiceal anomalies are extremely rare malformations that are usually found in the adult population as an incidental finding during laparotomy performed for other reasons. Abnormal development of the appendix usually takes the form of a double appendix. Accompanying intestinal, genito-urinary or vertebral malformations may be present when appendiceal duplications are detected in childhood.

Case Report : Presented herein is a case of perforated double appendix, which causes acute abdomen in a child, without any co-existing pathology.

Conclusion : Appendiceal anomalies are of great practical importance and a surgeon must bear them in mind during an operation. If he overlooks them, the patient undergoing surgery may experience grave consequences. They also may be a forensic issue in cases when a second explorative laparotomy reveals ‘previously removed’ vermiform appendix.     

A Minimally Invasive Technique for the Reduction of Calcaneal Fractures Using the Endobutton®

Calcaneal fractures are very common injuries, and closed reduction-percutaneous pinning, open reduction-internal fixation, and primary arthrodesis are the procedures used in the surgical treatment of these injuries. The aim of surgical treatment is to restore the normal biomechanics of the Achilles tendon and rearfoot by anatomic reduction of the articular surfaces. Minimization of the soft tissue complications commonly associated with the open treatment of calcaneal fractures can be achieved using indirect closed reduction and Kirschner wire or screw-assisted minimally invasive percutaneous osteosynthesis methods. In the present report, we describe a technique for the treatment of calcaneal fractures associated with soft tissues that are at risk of complications and present the cases of 3 patients treated with indirect, minimally invasive reduction of comminuted calcaneal fractures with the Endobutton^® fixation device. From our experience with this method, we believe it will be useful in cases of acute calcaneal fracture with pronounced soft tissue injury localized to the hindfoot.     

Assessment of peripapillary retinal nerve fiber layer thickness in children with vitamin B12 deficiency

Purpose

Vitamin B₁₂ deficiency is a worldwide problem. It affects all ages, including children. It is one of the most common nutritional disorders and can cause harmful effects on the nervous system. In this study, we compared the peripapillary retinal nerve fiber layer thickness (RNFLT) in a healthy control group with children with vitamin B₁₂ deficiency. In our study, we aimed to evaluate the effect of vitamin B₁₂ deficiency on the RNFLT in children with the optical coherence tomography (OCT) method.

Methods

Sixty-six children with a diagnosis of vitamin B₁₂ deficiency (patient group) and 66 age- and sex-matched healthy children (control group) were enrolled in this prospectively designed study. Blood counts, vitamin B₁₂ levels, folate levels, and full biochemical parameters were obtained for all the subjects in each group. Peripapillary RNFLT measurements were performed with Cirrus HD spectral domain OCT.

Results

The thickness of the superior retinal nerve fiber layer (RNFL) in the vitamin B₁₂ deficiency group was significantly lower than that of the control group (p?=?0.037). Although the average thickness of the RNFL was lower in the patient group, there was no statistically significant differences (p?=?0.216). In the vitamin B₁₂ deficiency group, the average RNFL thickness and the superior RNFL thickness were significantly correlated with vitamin B₁₂ levels (r ₁?=?0.353, p ₁?<?0.004 and r ₂?=?0.416, p ₂?=?0.001, respectively).

Conclusion

Our study showed that a deficiency in vitamin B₁₂, elsewhere it is important for the development of the central nervous system, is associated with a reduction in the thickness of the superior RNFL.