Morphometric comparison of the human corpus callosum in deaf and hearing subjects: an MRI study

Auditory cortices are interconnected to each other by fibers passing through the corpus callosum (CC). In totally deaf persons no auditory impulses are conveyed to the auditory cortices, hence the auditory pathways become nonfunctional. It was reported that there has been cross-modal plasticity between auditory, visual, and somatosensory cortices. In this study, our aim was to make a comparison in the CC morphometry in hearing subjects and in a selected group in which the auditory system was deprived before the age of 2. 18 deaf and 18 hearing male, handedness matched volunteers, ages varying between 28 and 56 years old were examined. Audiometrical tests were applied to both groups and then T1-weighted midsagittal MR images were obtained. Certain dimensions and areas were measured on these images. There were no statistically significant difference between deaf and hearing subjects, either when dimensions and areas were analyzed by multivariate analysis of variance or when areas were analyzed by univariate analysis of variance. Absence of any significant morphometric difference in the CC of deaf subjects could be thought as an evidence of reflection of functional cortical plasticity.     

Comparative analysis of event-related potentials during Go/NoGo and CPT: decomposition of electrophysiological markers of response inhibition and sustained attention

Neuropsychological tests target specific cognitive functions; however, numerous cognitive subcomponents are involved in each test. The aim of this study was to decompose the components of two frontal executive function tests, Go/NoGo (GNG) and cued continuous performance task (CPT), by analyzing event-related potentials (ERPs) of 24 subjects both in time and time-frequency domains. In the time domain, P1, N1, P2, N2 and P3 peak amplitudes and latencies and mean amplitudes of 100 ms time windows of the post-P3 time period were measured. For GNG, the N1 amplitude and for both GNG and CPT N2 amplitudes were significantly higher in the NoGo condition compared with the Go condition. P3 had a central maximum in the NoGo conditions of both paradigms in contrast to a parietal maximum in the Go conditions. All peaks except P1 and mean amplitudes of the post-P3 period were more positive in CPT compared to those of GNG. N1, N2 and P3 latencies were longer for the NoGo condition than the Go condition in the CPT. In time-frequency analyses, the NoGo condition evoked higher theta coefficients than the Go condition, whereas the CPT and GNG paradigms differed mainly in the delta band. These results suggest that theta component reflects response inhibition in both GNG and CPT, whereas delta component reflects the more demanding sustained attention requirement of the CPT. The latency prolongation observed with the NoGo condition of the CPT paradigm was thought to be due to perseverance/inhibition conflict enhanced by the primer stimuli in CPT.     

Improvement of radiologists' characterization of mammographic masses by using computer-aided diagnosis: an ROC study.

PURPOSE: To evaluate the effects of computer-aided diagnosis (CAD) on radiologists' classification of malignant and benign masses seen on mammograms. MATERIALS AND METHODS: The authors previously developed an automated computer program for estimation of the relative malignancy rating of masses. In the present study, the authors conducted observer performance experiments with receiver operating characteristic (ROC) methodology to evaluate the effects of computer estimates on radiologists' confidence ratings. Six radiologists assessed biopsy-proved masses with and without CAD. Two experiments, one with a single view and the other with two views, were conducted. The classification accuracy was quantified by using the area under the ROC curve, Az. RESULTS: For the reading of 238 images, the Az value for the computer classifier was 0.92. The radiologists' Az values ranged from 0.79 to 0.92 without CAD and improved to 0.87-0.96 with CAD. For the reading of a subset of 76 paired views, the radiologists' Az values ranged from 0.88 to 0.95 without CAD and improved to 0.93-0.97 with CAD. Improvements in the reading of the two sets of images were statistically significant (P = .022 and .007, respectively). An improved positive predictive value as a function of the false-negative fraction was predicted from the improved ROC curves. CONCLUSION: CAD may be useful for assisting radiologists in classification of masses and thereby potentially help reduce unnecessary biopsies.     

Laparoscopic visualization and dissection of retroperitoneal lymph nodes after patent blue dye injection: a pilot study

PURPOSE: Retroperitoneal lymph node dissection (RPLND) for testicular cancer is an important treatment modality for patients with stage I or IIA disease. Several urologists have previously reported the feasibility and usefulness of laparoscopic RPLND for such patients. The aim of this experimental pilot-feasibility study was to investigate whether visualization of retroperitoneal lymph nodes with patent blue violet (PBV) dye application is a feasible and an effective method during laparoscopic RPLND in a pig model. MATERIALS AND METHODS: Four 12-month-old white male pigs were included in the study. After PBV dye injection into the spermatic funicular and intratesticular parenchyma, the color changes in the retroperitoneal region were examined during transperitoneal laparoscopic visualization of the retroperitoneum. The time interval between the injection and the staining of lymphatic structures was measured for each intervention. Blue-stained retroperitoneal nodal tissues were dissected and removed by the laparoscopic approach and histologic examination was performed. RESULTS: After PBV dye injection, intense staining of the ipsilateral retroperitoneal lymphatic vessels and nodes was seen. Distribution of the PBV and the color changes of the retroperitoneal lymphatic structures were examined under laparoscopic vision in all pigs. All blue-stained retroperitoneal nodular tissues were removed laparoscopically and examined histologically. Histopathologic examination noted all specimens as lymph nodes with no toxic effects of PBV dye. CONCLUSION: We demonstrated that spermatic funicular injection of PVB dye is an effective and accurate method for retroperitoneal lymph node visualization in pigs. The use of this technique in combination with a laparoscopic approach makes RPLND easier and more effective.     

Axial rotation and mediolateral translation of the fibula during passive plantarflexion

BACKGROUND: Since the fibula is linked to the ankle as well as the knee joint, its importance for knee and ankle disabilities should be investigated. This study evaluates its movement during range of motion of the ankle. MATERIALS AND METHODS: An instrument, together with the experimental protocol, was devised to determine the relative motion of the fibula in reference to the tibia with motion of the ankle joint on 20 paired lower extremity cadaver specimens. RESULTS: It was demonstrated in all specimens that the fibula had a relative rotation around its longitudinal axis and mediolateral translation with reference to the tibia with ankle motion. The distal end of the fibula rotates more compared to the proximal end. The mediolateral translation of the proximal end of the fibula is rather close to that of the distal end. Although there was no consistent pattern for rotation, dorsiflexion caused lateral translation and plantarflexion caused medial displacement for most of the specimens. CONCLUSION: A novel, invasive but relatively simple test setup was devised. Movement of the fibula which is important for the kinematics and kinetics of the knee and ankle joints was evaluated by this new device. CLINICAL RELEVANCE: Evaluation of the fibula movement in normal lower extremities may lead to better understanding of its dynamic function which could have treatment implications for pathological conditions.     

Serum neuron-specific enolase as a predictor of short-term outcome and its correlation with Glasgow Coma Scale in traumatic brain injury

Elevated serum neuron-specific enolase levels are correlated with brain cell damage. Low scores according to Glasgow Coma Scale are also considered as serious poor prognostic factor. The aims of the study were to investigate whether there is a correlation between the two measurements in patients with traumatic brain injury and whether serum neuron-specific enolase levels have potential as a screening test to predict outcome. A total of 169 consecutive patients with traumatic brain injury admitted to our clinic between 2002 and 2005 are included in this study. Those patients, who had any major health problem before trauma, were excluded from the study. However, patients with isolated head injury were included in the study. Serial serum neuron-specific enolase concentrations taken at the first 2, 24, and 48 h after traumatic brain injury were analyzed. A computed tomography was performed on each patient on admission. Their Glasgow Coma Scale scores were recorded serially. The relationship between Glasgow Coma Scale scores and the serum neuron-specific enolase levels were assessed by statistical methods. There was a significant negative correlation between the serum neuron-specific enolase levels and Glasgow Coma Scale scores. The levels of neuron-specific enolase were significantly higher in the patients who died in 30 days after trauma and whose scores were lower than or equal to 8 points in Glasgow Coma Scale. Although there are several serious limitations of the use of neuron-specific enolase as a biomarker in traumatic brain injury (i.e., hypoperfusion, extracranial trauma, bleeding, liver, or kidney damage also increase the level of neuron-specific enolase), its concentrations may be useful as a practical and helpful screening test to identify neurotrauma patients who are at increased risk and may provide supplementary estimation with radiological and clinical findings.     

Range of motion of the first metatarsophalangeal joint after chevron procedure reinforced by a modified capsuloperiosteal flap

BACKGROUND: This study analyzed the range of motion of the first metatarsophalangeal joint following the chevron procedure with increased stabilization using a modified capsuloperiosteal flap in the treatment of hallux valgus cases. MATERIALS AND METHODS: Forty-three feet of 40 patients were treated with modified chevron osteotomies. The patient selection criteria included failure of conservative treatment, painful deformity, age between 18 and 50, hallux valgus and intermetatarsal angles less than 40 degrees and 17 degrees, respectively, and no osteoarthritic changes of the metatarsophalangeal joint. The passive range of motion of the first metatarsophalangeal joint was compared to the hallux valgus and intermetatarsal angles. RESULTS: The mean age of patients was 30.9 +/- 9.0 (range, 18 to 46) years. The preoperative mean hallux valgus angle was 32.2 (range, 22 to 40 degrees), whereas postoperatively it was 13.1 (range, 3 to 22 degrees). The preoperative mean passive total range of motion, dorsiflexion and plantar flexion were found to be 80.2 (range, 71 to 99 degrees), 66.8 (51 to 86) degrees and 13.4 (range, 7 to 23 degrees), respectively, whereas postoperatively these values were 69.2 (range, 48 to 85 degrees), 58.6 (range, 43 to 75) degrees and 10.8 (range, 1 to 20 degrees). According to Bonney and MacNab subjective scores, the feet were evaluated as follows: 12 as excellent, 26 as good, and 5 as moderate. According to objective scores, the evaluation was as follows: 27 as excellent, 14 as good, 1 as moderate, and 1 as poor. CONCLUSION: We believe that the chevron procedure reinforced by modified capsuloperiosteal flap causes minimal irritation and damage to adjacent soft tissues. Furthermore, we conclude that this method is a benefical means of managing moderate hallux vagus deformities by decreasing the stiffness after surgery.     

A giant extrasynovial osteochondroma in the infrapatellar fat pad: end stage Hoffa’s disease

The infrapatellar fat pad of Hoffa is commonly injured but rarely discussed in the orthopaedic literature. Hoffa’s disease is the extension of various traumatic events due to impingement and inflammation of the infrapatellar fat pad and known as a vague reason for anterior knee pain. Inflammation is foreground during acute phase of the disease while impingement due to fibrosis and scar tissue of infrapatellar fat pad plays a major role in the chronic phase. The osteochondroma of the infrapatellar fat pad secondary to the Hoffa’s disease can be more problematic. Although, the fibrocartilaginous transformation and osteochondral metaplasia of infrapatellar fat pad was pointed out frequently in the literature, the published papers seem far from clarifying the relation between chronic impingement and formation of osteochondroma. We present a case of a giant ossifying chondroma in the infrapatellar fat pad that resulted from chronic Hoffa’s disease. Complete open resection was performed successfully after arthroscopic examination. The infrapatellar fat pad contains the entire progenitor cells for the development of an osteochondroma and chronic impingement may have promoter affect on this issue, thus, an osteochondroma may occur at the end-stage Hoffa’s disease.     

Current status of high-intensity focused ultrasound for prostate cancer: Technology,clinical outcomes,and future

Based on a review of recently published articles, we evaluated the current status of high-intensity focused ultrasound (HIFU) as a primary treatment option for localized prostate cancer and as a salvage therapy when radiation has failed. With mid-and long-term progression-free survival rates around 70%, negative postoperative prostate biopsies almost 90%, and an excellent morbidity profile, primary HIFU appears to be a valid alternative to active surveillance protocols in low-risk patients and standard therapies in patients with life expectancies of 10 or fewer years. Moreover, HIFU has a considerable potential for local-only recurrence after radiation failure. HIFU is a recent technology, and many improvements will undoubtedly expand its future indications and use for the management of prostate cancer.     

The effect of temporary aneurysm clip on the common carotid artery of atherosclerotic rabbits

BACKGROUND: We compared the effect of temporary aneurysm clips on atherosclerotic and nonatherosclerotic CCA of rabbits by morphometric and ultrastructural methods. METHODS: The rabbits (N = 12) were divided into 2 groups: the first group was fed a 2% cholesterol diet, and the second group, a normal diet for 4 weeks. Atherosclerotic lesions developed after 4 weeks. Temporary aneurysm clips were placed on the left CCA of both groups; the right CCA of both groups served as control. Thus, a total of 4 groups were used: atherosclerotic (A), atherosclerotic/clip (AC), nonatherosclerotic (NA), and nonatherosclerotic/clip (NAC). Temporary aneurysm clips were applied for 1, 5, and 10 minutes in the AC and NAC groups. No temporary clip was placed on the right CCA (A and NA groups). The affected parts of the CCA via clips were examined under light microscope and SEM. RESULTS: Comparison of atherosclerotic and nonatherosclerotic CCA of rabbits under light microscope indicated that the wall of atherosclerotic CCA was thicker than that of nonatherosclerotic CCA. The difference between the thickness of atherosclerotic and nonatherosclerotic CCAs was significant. SEM analyses showed that in nonatherosclerotic CCAs, the effect of temporary aneurysm clips was seen after 10 minutes, but in atherosclerotic CCAs, the effect was seen within the 1st minute of clipping and continued in the 5th and 10th minutes. CONCLUSION: The duration of temporary clipping should be decreased for the neurovascular surgery of atherosclerotic patients.