Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms^-1 to 0.71 ms^-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.     

Human breast cancer in vivo: H-1 and P-31 MR spectroscopy at 1.5 T

To assess the potential of in vivo magnetic resonance (MR) spectroscopy for breast cancer, hydrogen-1 and phosphorus-31 MR spectra of five malignant human breast tumors were compared with those of unaffected breast tissue. The water-to-fat ratio was high in the tumors (average, 2.2) but low in the unaffected tissue (average, 0.3). The P-31 spectrum of normal breast tissue showed low levels of phosphomonoesters (PMEs), inorganic phosphate, phosphodiesters (PDEs), and ATP. In addition, an intense phosphocreatine (PCr) signal was observed in breast tissue of young women: The relative intensities of the PCr and ATP signals had a mean value of 1.9. The tumor spectrum showed elevated levels of PMEs, Pi, and PDEs, while no PCr was seen (PCr/ATP less than 0.2). In two breast cancers treated with radiation therapy, resulting in a decrease of tumor volume of more than 50%, a similar change in the tumor P-31 spectrum was observed: An intense PCr signal developed (PCr/ATP = 1.1). Control experiments indicated that the appearance of PCr after radiation therapy was the result of a radiation-induced metabolic change in the tumor itself.     

Alkaloids from Eschscholzia californica and their capacity to inhibit binding of [3H]8-Hydroxy-2-(di-N-propylamino)tetralin to 5-HT1A receptors in Vitro

A 70% ethanol extract of California poppy (Eschscholzia californica) was able to bind to 5-HT(1A) and 5-HT(7) receptors at 100 mug/mL. The subsequent isolation procedure yielded the known alkaloids californidine (1), escholtzine (2), N-methyllaurotetanine (3), caryachine (4), and O-methylcaryachine (5), along with a new pavine alkaloid, 6S,12S-neocaryachine-7-O-methyl ether N-metho salt (7). The structure of 7 was determined by spectroscopic data interpretation, while the absolute stereochemistry was determined by means of circular dichroism. From the results obtained from the radioligand-binding assay of the pure compounds, including the commercially available protopine (6), it was evident that the activity on the 5-HT(1A) receptor was at least partly due to the presence of the aporphine alkaloid 3, which showed the highest inhibition of [(3)H]8-hydroxy-2-(di-N-propylamino)tetralin ([(3)H]8-OH-DPAT) binding with an EC(50) value of 155 nM and a K(i) of 85 nM.     

Causes and Patterns of Aborting a Robot-Assisted Arthroplasty

For a successful robot-assisted arthroplasty, every step should be executed harmoniously. However, when we encounter serious obstacles during surgery, it is sometimes better to abort the procedure in a timely manner. This study investigated the possible causes and patterns of aborted robot-assisted arthroplasties. Of 100 consecutively planned robot-assisted arthroplasties, 22 cases were aborted. Most involved total knee arthroplasty (21/22 cases). We classified the causes according to the stage at which they occurred and the type of error. Abortions after starting the milling procedure and abortions due to an interactive factor were the most common. We believe that this study can guide surgeons to effective decision making during robot-assisted arthroplasty.     

Enhanced bone formation by transforming growth factor-beta1-releasing collagen/chitosan microgranules

Collagen/chitosan composite microgranules were fabricated as bone substitutes for the purpose of obtaining high bone-forming efficacy. The microgranules have the flexibility to fill various types of defect sites with closer packing. The interconnected pores formed spaces between the microgranules, which allowed new bone ingrowth and vascularization. In addition, the transforming growth factor-beta 1 (TGF-beta1) was incorporated into the microgranules in order to improve bone-healing efficacy. The collagen/chitosan microgranules were fabricated by dropping a mixed solution into a NaOH/ethanol solution. TGF-beta1 was loaded into the collagen/chitosan microgranules by soaking the microgranules in a TGF-beta1 solution. Scanning electron microscopy (SEM) observations and experiments examining the release of TGF-beta1 from chitosan and the collagen/chitosan microgranules were performed. SEM was used to examine the cell morphologies on the microgranules and cell proliferation was evaluated using a dimethylthiazole tetrazolium bromide assay. The differentiated cell function was assessed by measuring the alkaline phosphatase (ALPase) activity as well as detecting an osteocalcin assay. The in vivo bone-regeneration experiments were performed using a rabbit calvarial defect model. TGF-beta1 was released from the collagen/chitosan microgranules at a therapeutic concentration for 4 weeks. SEM indicated that the seeded osteoblastic cells were firmly attached to the microgranules and proliferated in a multilayer manner. The proliferation of the osteoblasts on the TGF-beta1-loaded microgranules was the highest among the different types of microgranules tested. The ALPase activity and osteocalcin level of all the samples increased during the culture period, and the TGF-beta1-loaded microgranules had a significantly higher ALPase activity and osteocalcin content than the other microgranules. The TGF-beta1-loaded microgranules demonstrated a higher bone-regenerative capacity in the rabbit calvarial defects after 4 weeks than the TGF-beta1-unloaded microgranules.     

Volumetric Analysis of Cerebellum in Short-Track Speed Skating Players

The cerebellum is associated with balance control and coordination, which might be important for gliding on smooth ice at high speeds. A number of case studies have shown that cerebellar damage induces impaired balance and coordination. As a positive model, therefore, we investigated whether plastic changes in the volumes of cerebellar subregions occur in short-track speed skating players who must have extraordinary abilities of balance and coordination, using three-dimensional magnetic resonance imaging volumetry. The manual tracing was performed and the volumes of cerebellar hemisphere and vermian lobules were compared between short-track speed skating players (n?=?16) and matched healthy controls (n?=?18). We found larger right cerebellar hemisphere volume and vermian lobules VI?CVII (declive, folium, and tuber) in short-track speed skating players in comparison with the matched controls. The finding suggests that the specialized abilities of balance and coordination are associated with structural plasticity of the right hemisphere of cerebellum and vermian VI?CVII and these regions play an essential role in balance and coordination.