Cross-sectional Area In Group Research Articles

Paraspinal muscle damage in intermuscular and conventional lumbar spinal fixation: A comparative study

BackgroundThe conventional approach for lumbar fixation involves subperiosteal muscle dissection, and disruption of normal blood and nerve supply of the back muscles. Different transmuscular approaches, have been described for better preservation of normal neurovascular structures. This leads to less muscle damage and atrophy and consequently less postoperative pain. PurposeCompare between transmuscular approach and conventional approach for lumbar spine fixation. Study DesignA prospective comparative study carried at Neurosurgery Department, Zagazig University, during the period from February 2018 to February 2019. Patients and methods60 patients with degenerative lumbar instability were included in this study and randomly assigned to one of the two groups, Group A (transmuscular group) and Group B (conventional group). Outcome was assessed, using postoperative Visual Analogue Score (VAS) for back pain, change in pre and postoperative levels of Creatine Phospho-Kinase (CPK), and the postoperative change in the cross-sectional area of multifidus muscle, measured using axial CT cuts. ResultsAs regards the hospital stay, it was 1.5 days less in Group A than Group B (P<0.001). The serum CPK increased by only 3 folds in Group A in comparison to 15 folds increase in Group B, indicating less muscle damage (P<0.001). Postoperative Visual Analogue Scale (VAS) for back pain was higher in Group B than Group A (P<0.001). Decrease in cross-sectional muscle area in Group B (40%) was more than the decrease in cross-sectional area in Group A (10%), (P<0.001), which means more muscle atrophy in Group B than in Group A. ConclusionUsing the transmuscular approach for lumbar spine fixation is a more conservative approach, than the conventional approach, with less muscle atrophy, better preservation of anatomy, and less postoperative pain.

The influence of aerobic exercise on the structure, function and expression of energy metabolism-related molecules in skeletal muscle of aged rats

Objective To examine the effects of aerobic exercise on muscle morphology, oxidation resistance, energy metabolism, mitochondrial biogenesis-related signal transduction pathway molecules, and energy metabolism-related enzyme proteins expression in aged rats and to explore the molecular mechanisms of skeletal muscle aging and aerobic exercise intervention. Methods Male Sprague Dawley rats were divided into a normal group, a model group, and an exercise group, with the latter two groups receiving a subcutaneous injection of 10% D-galactose(0.1 mg·g-1·d-1)for 10 weeks.Then aerobic and anaerobic exercise capacity of each group were tested by treadmill; the cross-sectional area of rats' gastrocnemius was examined via light microscopy; levels of serum superoxide dismutase(SOD)activity and malondialdehyde(MDA)were determined by spectrophotometry; serum β-Galase levels were tested by enzyme-linked immunosorbent assay(ELISA); levels of adenosine triphosphate(ATP), adenosine diphosphate(ADP)and adenosine monophosphate(AMP)in gastrocnemius tissue were measured by high performance liquid chromatography(HPLC)-ultraviolet detection; expression levels of mitochondrial biosynthesis-related signal transduction molecules(such as p38MAPK, CaMKⅡ, PGC-1α, MEF2C, COXⅣ and ATPase)were tested by real-time RT-PCR. Results Compared with the normal group, the model group's cross-sectional area of muscle fibers, serum SOD activity, ATP content, and EC values all markedly decreased, while serum MDA, β-Galase, AMP content in skeletal muscle significantly increased(all P<0.05). Levels of mRNA expression of CaMKⅡ, MEF2C, ATPaseβ, COXIV, and PCG-1 alpha in model rats notably decreased(all P<0.05), whereas mRNA expression levels of P38MAPK significantly increased(P<0.05). Compared with the model group, aerobic exercise increased the cross-sectional area of muscle fibers(P<0.01)and serum SOD activity(P<0.05), reduced serum MDA content(P<0.01), clearly increased CaMKⅡ and ATPaseβ mRNA expression(both P<0.01), and reduced the expression of P38MAPK mRNA(P<0.01). Conclusions Aerobic exercise can improve the activity of SOD, reduce the accumulation of oxygen free radicals, resist oxidation damage, correct the abnormal activity of P38MAPK, and promote the expression of mitochondrial biosynthesis-related signal molecules, such as CaMKⅡ, PCG-1 alpha, and MEF2C, thus boosting the expression and activity of energy metabolism enzyme protein COX Ⅳ, ATPase, promoting energy metabolism, improving the production of ATP, and slowing down the ageing process of the body and skeletal muscle. Key words: Aerobic exercise; Aging; Skeletal muscle; Antioxidant capacity; Energy metabolism; Mitochondrial biogenesis

Ultrasonographic and Electrophysiological Evaluation of the Ulnar Nerve in Patients Diagnosed With Carpal Tunnel Syndrome

In this study, we evaluated the ulnar nerve of patients diagnosed with carpal tunnel syndrome (CTS) using electrophysiology and ultrasonography. The study included 86 patients (136 hands) and 39 controls (78 hands) with normal electrophysiological assessment. According to Bland's classification, patients were divided into group 1 (grades 1-3 CTS) or group 2 (grades 4-6 CTS). The ulnar nerve was evaluated at the wrist using nerve conduction studies and ultrasonography. The sensory velocity was slower in group 2 than in group 1 (P < 0.001), slower in group 2 than in controls (P < 0.001), and slower in group 1 than in controls (P < 0.005). Although the ultrasonography results showed a reduction in the ulnar nerve cross-sectional area in group 1 compared with controls, the difference was not statistically significant. However, the reduction was significant in group 2 compared with group 1 and controls (P < 0.001). Based on our study results, the ulnar nerve is affected electrophysiologically and morphologically in patients with CTS, especially those with advanced-stage CTS.

Cross-sectional area of hamstring tendon autograft after anatomic triple-bundle ACL reconstruction.

The purpose was to evaluate the cross-sectional area changes in hamstring tendon autografts up to 5years after the anatomic triple-bundle anterior cruciate ligament (ACL) reconstruction. A total of 178 MRI scans from 139 patients (35 males, 104 females, mean age 30.4years) with the anatomic triple-bundle ACL reconstructions were obtained to evaluate the cross-sectional area of the ACL grafts. They were classified into seven groups according to the period from reconstruction to MRI evaluation: Group -2months (m.), Group 3-6m., Group 7-12m, Group 1-2years (y.), Group 2-3y., Group 3-4y., and Group 4y.-. Intra-operatively, the cross-sectional area of the graft was measured directly using a custom-made area micrometre. Post-operatively, the cross-sectional area of the grafts' mid-substance was measured with oblique axial MRI slices perpendicular to the long axis of the grafts using a digital radiology viewing program. The percent increase in the cross-sectional area was calculated by dividing the post-operative cross-sectional area by the intra-operative cross-sectional area. The mean percent increase in the cross-sectional area in Groups -2m., 3-6m., 7-12m., 1-2y., 2-3y., 3-4y., and 4y.- was 105.7±14.0, 134.9±20.0, 137.3±27.8, 129.4±22.2, 124.1±20.4, 117.8±16.9, and 117.1±17.2%, respectively. The percent increase in Groups 3-6m., 7-12m., and 1-2y. was significantly greater than in Group -2m., while that in Group 4y.- was significantly less than in Group 7-12m. The cross-sectional area of the hamstring tendon autografts after the anatomic triple-bundle ACL reconstruction increases over time up to 1year post-operatively, decreases gradually thereafter, and reaches plateau at around 3years. Retrospective case series, Level IV.

An equation to calculate the actual methylene middle parameter as a function of temperature

Methylene middle parameter αCH2(γCH2)0.5, the product of the methylene group's cross-sectional area (αCH2) and the root square of its dispersive free energy (γCH2), is the key parameter to calculate the dispersive surface components of solids (γsd) using inverse gas chromatography (IGC) at different temperatures. The only method reported to calculate αCH2(γCH2)0.5 as a function of temperature is the Dorris–Gray method. However, the conventional values of αCH2(γCH2)0.5 calculated by the Dorris–Gray method depend heavily on theoretical aspects. This paper establishes a novel equation calculating the actual αCH2(γCH2)0.5 as a function of temperature using the latest and most accurate surface parameters of seven successive n-alkanes. The obtained actual αCH2(γCH2)0.5 values are slightly higher those of the conventional αCH2(γCH2)0.5. At 20°C, the actual αCH2(γCH2)0.5 generates γsd values less than those generated using the conventional αCH2(γCH2)0.5 by ∼3%, and this reduction in calculated γsd values increases linearly to become ∼5% at 100°C. Therefore, using the new actual αCH2(γCH2)0.5 seems to mitigate the discrepancy between the γsd values measured by IGC and those measured by the contact angle method.

Multidetector-row Computed Tomography Evaluation of Bilateral Bronchial Narrowing Associated with Increased Pulmonary Blood Flow in Children with Congenital Heart Disease

Quantitative assessment of bilateral bronchial narrowing in children with congenital heart disease (CHD) with a left-to-right shunt has not yet been reported. In the present study, main bronchial size was evaluated bilaterally in normal subjects using multidetector-row computed tomography (MDCT), and the feasibility for diagnosis of bronchial narrowing in children with CHD associated with increased pulmonary blood flow was investigated. The short-axis diameter, long-axis diameter, and the cross-sectional area of the bilateral bronchi were measured immediately proximal to the origin of the superior lobar branch in 86 children aged 1-52 months. Subjects were divided into three groups as follows: group 1 (normal subjects; n = 52), group 2 (asymptomatic left-to-right shunt group; n = 25), and group 3 (symptomatic left-to-right shunt group with respiratory insufficiency; n = 9). Age, height, weight, and body surface area were significantly correlated with short- and long-axis bronchial diameters, and bronchial cross-sectional area in group 1. In group 2, the left bronchial cross-sectional area was significantly lower than group 1 (P < .001), whereas the right bronchial area was not significantly different. In group 3, the right bronchial area was significantly lower than that in groups 1 and 2 (P < .05). Although the left bronchial area in group 3 was significantly lower than in group 1 (P < .001), it was not significantly different from that in group 2. Our study suggests that MDCT can be used to quantify bilateral bronchial narrowing. Left main bronchial obstruction develops during the early stage of heart failure, followed by the development of right bronchial narrowing.

Size and Composition Changes in Diaphragmatic Fibers in Rats Exposed to Chronic Hypercapnia

To test the hypothesis that chronic hypercapnia changes the composition of the respiratory muscle by continuous augmentation of ventilation. Eighteen male Wistar rats were housed in 10% CO(2) in air for 19 weeks, and their minute ventilation V(E) was measured every 6 weeks. The diaphragm, excited at 19 weeks of exposure, was classified as fiber type I, IIa, or IIb. Cross-sectional areas of individual fibers were measured. Fibers with a target-like appearance on reduced nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR) stain also were counted. The data were compared with those of rats kept in room air. The mean (+/- SD) PaCO(2) after 19 weeks of sustained hypercapnia was 71.0 +/- 4.7 mm Hg. The V(E) remained at a high level until 12 weeks of exposure, and then it significantly decreased at week 18. In a comparison with the control rats, a larger number of type I fibers and a smaller number of type IIb fibers were found in the diaphragm of the chronically hypercapnic rats. In addition, the latter group's cross-sectional area revealed fibers of a significantly smaller diameter. Target-like fibers were observed in 5% of the NADH-TR-stained fibers in the chronically hypercapnic rats but were not seen in the control rats. By increasing the ratio of fatigue-resistant fibers, the diaphragm was able to adapt to a sustained load induced by hypercapnia. However, this adaptive process was accompanied by a degenerative change in the tissue.

Systemic administration of rhIGF-I or rhIGF-I/IGFBP-3 increases cortical bone and lean body mass in ovariectomized rats

The purpose of this study was to compare dose-related effects on cortical bone and lean body mass following subcutaneous administration of rhIGF-I alone, or bound to an equimolar amount of rhIGFBP-3 to adult Ovx rats. At the age of 16 weeks, rats were ovariectomized or sham-operated and were allowed 8 weeks to develop osteopenia. After being divided into control (saline treated) or treatment groups, rats were injected daily during an 8-week period with 0.9 and 2.6 mg/kg of rhIGF-I, or with 0.9, 2.6, and 7.5 mg/kg of rhIGF-I bound to rhIGFBP-3. Fluorescent bone markers were given 9 and 2 days prior to necropsy. Body weights and lean body mass were monitored throughout the experiment. Cortical bone histomorphometry was performed on tibial cross-sections at the tibiofibular junction, and endochondral bone growth was measured at the distal femoral metaphysis. All rats treated with rhIGF-I or the rhIGF-I/IGFBP-3 complex had increased body weights, corresponding to a dose-dependent increase in lean body mass. Endochondral growth was slightly increased in all experimental groups, but was not dose-dependent. A dramatic increase in periosteal, modeling-dependent formation, coupled with decreased or unchanged resorption on the endocortical envelope resulted in a dose-dependent increase in cortical thickness and cross-sectional area in groups treated with the complex of rhIGF-I/IGFBP-3. This complex appeared to be more effective in promoting positive musculoskeletal changes than rhIGF-I alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic Administration of rhIGF-I or rhIGF-I/IGFBP-3 Increases Cortical Bone and Lean Body Mass in Ovariectomized Rats

The purpose of this study was to compare dose-related effects on cortical bone and lean body mass following subcutaneous administration of rhIGF-I alone, or bound to an equimolar amount of rhIGFBP-3 to adult Ovx rats. At the age of 16 weeks, rats were ovariectomized or sham-operated and were allowed 8 weeks to develop osteopenia. After being divided into control (saline treated) or treatment groups, rats were injected daily during an 8-week period with 0.9 and 2.6 mg/kg of rhIGF-I, or with 0.9, 2.6, and 7.5 mg/kg of rhIGF-I bound to rhIGFBP-3. Fluorescent bone markers were given 9 and 2 days prior to necropsy. Body weights and lean body mass were monitored throughout the experiment. Cortical bone histomorphometry was performed on tibial cross-sections at the tibiofibular junction, and endochondral bone growth was measured at the distal femoral metaphysis. All rats treated with rhIGF-I or the rhIGF-I/IGFBP-3 complex had increased body weights, corresponding to a dose-dependent increase in lean body mass. Endochondral growth was slightly increased in all experimental groups, but was not dose-dependent. A dramatic increase in periosteal, modeling-dependent formation, coupled with decreased or unchanged resorption on the endocortical envelope resulted in a dose-dependent increase in cortical thickness and cross-sectional area in groups treated with the complex of rhIGF-I/IGFBP-3. This complex appeared to be more effective in promoting positive musculoskeletal changes than rhIGF-I alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of reduced glomerular filtration rate in chronic malnutrition.

To determine the physiological basis for the low glomerular filtration rate in chronic malnutrition, micropuncture studies were performed in Munich-Wistar rats chronically pair-fed isocaloric diets of either low (group 1, nine rats) or high protein content (group 2, nine rats). Despite the absence of hypoalbuminemia, average values for single nephron and total kidney glomerular filtration rate were nearly 35% lower in group 1 than in group 2. Mean values for glomerular capillary and Bowman's space hydraulic pressures were essentially identical in the two groups, thereby excluding glomerular transcapillary hydraulic pressure difference as the cause for the low filtration rates in group 1 animals. On the other hand, average glomerular capillary plasma flow rate and glomerular capillary ultrafiltration coefficient were significantly lower (by approximately 25 and approximately 50%, respectively) in group 1 than in group 2. The fall in glomerular capillary plasma flow rate was the consequence of increased afferent and efferent arteriolar resistances. Plasma and erythrocyte volumes were found to be equal in five additional pairs of group 1 and group 2 rats. Thus, the substantial alterations in the ultrafiltration coefficient, glomerular capillary plasma flow rate, and renal arteriolar resistances responsible for the low filtration rate in group 1 animals were not merely a consequence of decreased circulating blood or plasma volumes. Mean values for glomerular cross sectional area were significantly lower in group 1 than in group 2 despite similar values for kidney weight in the two groups. This reduction in glomerular cross sectional area in group 1 rats is presumed to reflect a decrease in effective filtration surface area and therefore likely accounts, at least in part, for the decline in ultrafiltration coefficient observed in this group.Finally, since the daily caloric intake of group 2 animals was restricted because of pair feeding requirements tied to the group 1 rats, we studied a third group of seven rats (group 3) allowed an ad lib. intake of the same high protein diet as given to group 2 rats. Average values for single nephron glomerular filtration rate and its determinants were found to be indistinguishable between groups 2 and 3. These results suggest that low protein intake, rather than calorie deficiency per se, is primarily responsible for the reduction in filtration rate seen in this experimental model of chronic malnutrition.