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.     

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.     

The detection of sensitivity of proprioception by a new clinical test: The dual joint position test

Objectives

To date, very few studies have paid attention to the joint sense (proprioception) of toes other than the big toe. We evaluated the sensitivity of joint position sense at the joint of the great toe in comparison to other digits, and with that determined by the dual digit stimulation test, in a sample of healthy normal controls and patients with clinical diagnosis of the lemniscal system dysfunction.

Material and methods

Seventy-two patients with lemniscal system dysfunction (55 clinically definitive multiple sclerosis, 17 vasculitis) and 110 healthy volunteers participated in the study. All subjects underwent the joint position sense test of all digits of upper and lower extremities. The position sense resulting from the combined operation of the joints of the second and the fourth digits (simultaneous two digits position sense) was also measured and subsequently compared with the results of the great toe position sense.

Results

Upper extremities: no difference was found in recognition of the position sense in the single digits of the upper extremities between patients and healthy volunteers. There was a significant difference in the dual joint position test of the right upper extremity between patients and the case group (p < 0.05) but not in the left upper extremity. Lower extremities: there was no significant difference in proprioception of the great toe neither in the right and nor in the left side between patients and normal subjects. However, the joint position sense of other single digits was deteriorated in the patients, a difference that was significant compared to normal controls (p < 0.05). Additionally, patients and normal controls displayed a difference in dual digit position sense of the right and left lower extremities (p < 0.05).

Conclusions

We show in this paper that the proprioception of simultaneous dual digits is diminished in patients when compared to a single digit position sense. Moreover, the great toe proprioception is less sensitive than other digits. Taken together, these observations lend evidence for a new clinical method which we named as dual joint position test. We suggest this novel method offers clinical utility to demonstrate lemniscal system dysfunction.     

Effects of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention

This study aimed to compare the effect of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention. Crowns were fabricated for 50 molar teeth, and specimens were assigned to 5 groups based on treatment method: untreated control group (CON), laser group (LAS), sodium fluoride group (FLU), Oxagel oxalate group (OXA), and Gluma primer group (GLU). All crowns were luted with glass-ionomer cement. Tensile force was applied for crown dislodgement. Recorded forces and calculated retentive strengths were as follows: CON (261 N) > LAS (223 N) = FLU (208 N) > GLU (161 N) = OXA (147 N) (P < .05). The differences in force magnitudes between all groups were significant (P < .05), except for LAS versus FLU and GLU versus OXA. The retention decrease was 15% for LAS, 20% for FLU, 38% for GLU, and 44% for OXA. Laser treatment had a less negative effect on retention for crowns luted with glass-ionomer cement than the other treatment modalities, and it may be a more suitable desensitization method if crown retention can be moderately sacrificed.     

The prosthodontic restoration of a self-inflicted gunshot maxillofacial defect: a short-term follow-up case report

A self-inflicted gunshot maxillofacial defect was restored with dental implants and various attachments. Following mandibular surgical reconstruction, a fixed full-arch implant-supported prosthesis was fabricated. The maxillary defect was restored with an obturator retained with bar-clip and ball attachments. Crowns with an unfavorable crown-to-root ratio were used to rectify a compromised unilateral interocclusal space. Functional rehabilitation was achieved without any pathologic sequelae and maintained over a 1-year observation period. Provision of a fixed implant-retained mandibular prosthesis opposing a specific design for a maxillary obturator provided short-term and optimistic prognosis in the management of a serious traumatic injury.