Intra‐articular injection of hyaluronan restores the aberrant expression of matrix metalloproteinase‐13 in osteoarthritic subchondral bone

Subchondral bone is a candidate for treatment of osteoarthritis (OA). We investigated the effects of intra‐articular injection of hyaluronan (IAI‐HA) on subchondral bone in rabbit OA model. OA was induced by anterior cruciate ligament transection, with some rabbits receiving IAI‐HA. OA was graded morphologically, and expression of mRNA was assessed by real‐time RT‐PCR. Tissue sections were stained with hyaluronan‐binding protein, and penetration of fluorescent hyaluronan was assessed. The in vitro inhibitory effect of hyaluronan on MMP‐13 was analyzed in human osteoarthritic subchondral bone osteoblasts (OA Ob) by real‐time RT‐PCR and ELISA. Binding of hyaluronan to OA Ob via CD44 was assessed by immunofluorescence cytochemistry. Expression of MMP‐13 and IL‐6 mRNA in cartilage and subchondral bone, and morphological OA grade, increased over time. IAI‐HA ameliorated the OA grade and selectively suppressed MMP‐13 mRNA in subchondral bone. IAI‐HA enhanced the hyaluronan staining of subchondral bone marrow cells and osteocyte lacunae. Fluorescence was observed in the subchondral bone marrow space. In OA Ob, hyaluronan reduced the expression and production of MMP‐13, and anti‐CD44 antibody blocked hyaluronan binding to OA Ob. These findings indicate that regulation of MMP‐13 in subchondral bone may be a critical mechanism during IAI‐HA. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:354–360, 2011     

Influence of oral appliances on craniocervical posture in obstructive sleep apnea–hypopnea syndrome patients

PurposeThe existence of a relationship between head posture and mandibular function has been discussed by several authors. However, the relationship between head posture and the cervical spine in patients with obstructive sleep apnea–hypopnea syndrome (OSAHS) who are using oral appliances (OAs) remains unknown. The aim of this study was to evaluate the changes in the cervical spine associated with the use of OAs in patients with OSAHS.MethodsFifteen patients (4 females and 11 males; mean age, 48 years) diagnosed with OSAHS were randomly selected. An OA was fabricated individually for each patient. Two lateral cephalometric radiographs were taken while the patient was sitting awake in an upright position. The first radiograph was taken in the intercuspal position and the second was taken while the subject was wearing the OA. Analyses based on the sella–nasion (SN) line were performed in the lateral cephalogram. Comparison of craniocervical angles in patients with and without the OA was performed using Wilcoxon's signed-rank test.ResultsCephalometric analysis showed that the craniocervical angles (CVT-C2V and SN-C4) with OA were higher than those without OA (P < 0.05). It seems that the OA caused a significant flexion of the cranium on the upper cervical spine. A significant increase in the craniocervical angle occurred in the fourth cervical segment.ConclusionThe changes in forward flexion of the upper cervical spine found in this study imply that changes in the craniocervical relationship should be evaluated periodically after an OA has been inserted.     

The mechanism of speech perception using multichannel cochlear implant

The mechanism of speech perception in patients with Australian multi-channel cochlear implant was investigated. 1) Vowel recognition abilities of patients were sufficient with this implant, whereas, consonant recognition abilities were insufficient. 2) Although the cochlear hair cells were functionally damaged, cochlear nerves had the ability to characterize frequency. 3) The signals from the implanted material were very simple compared to those from normal cochlea, however these patients could understand speech well, perhaps due to aid from the central nervous system.     

Effect of vestibular nerve section on cytochrome oxidase activity in the vestibular ganglion cells of the squirrel monkey

Cytochrome oxidase (CO) activity of the vestibular ganglion cells of the squirrel monkey was demonstrated histochemically under normal and experimental conditions. Under general anesthesia, right vestibular nerve section was performed on adult squirrel monkeys between the vestibular ganglion and brain stem. The left side was left intact and was used as a within-animal normal control. One squirrel monkey that did not undergo vestibular nerve section was also included in the normal group. Following a survival period of seven months, neurons in the vestibular ganglion of both sides were examined. In the normal control sides, a significant negative correlation between the size of the neuron and its optical density for CO stain was observed. Many neurons in the vestibular ganglion survived after vestibular nerve section, but their cell sizes and optical densities of CO stain decreased compared with those of the control side.     

Pumping and clearance function of the eustachian tube

The purpose of this study was to clarify the relationship between mucociliary and muscular clearance in the eustachian tube. Displacement of various viscosities and volumes of a colored fluid through the tube was observed endoscopically in cats. To test ciliary clearance, the fluid was placed in either the tympanum or the mastoid bulla. The interval between the instillation and beginning of discharge of the fluid from the pharyngeal orifice of tube was measured. Clearance time was prolonged with fluids having high viscosities, and the clearance time from the tympanum was shorter than that from the mastoid bulla. To test muscular clearance, the tensor veli palatini muscle was stimulated electrically to simulate swallowing, and the number of contractions necessary for massive discharge of the fluid was counted. Massive discharge occurred only with low viscosity fluid placed in the tympanum, whereas small amounts of highly viscous fluid were cleared by linear discharge. The authors concluded that when the volume of middle ear effusion was small, the fluid was cleared by mucociliary clearance. When the volume of fluid was large, the low viscosity fluid was cleared by muscular clearance only, while highly viscous fluid was cleared both by ciliary and muscular clearance.     

The origin of autonomic nerves of the Eustachian tube as studied by the horseradish peroxidase tracer method

Autonomic innervation of the Eustachian tube mucosa was investigated by the horseradish peroxidase retrograde tracing method. The Eustachian tube mucosa was found to be sympathetically innervated by fibres originating in the ipsilateral superior and middle cervical ganglia, but not by those originating in the stellate ganglion. The Eustachian tube mucosa was also innervated by fibres originating in the pterygopalatine ganglion, but not by those originating in the otic ganglion. The innervation from the pterygopalatine ganglion was considered to be parasympathetic.     

Respiratory Syncytial Virus Infection in Infants with Congenital Heart Disease and Treatment with Human Leukocyte lnterferone

Between 1980 and 1986, we observed lower respiratory-tract infection caused by respiratory syncytial virus (RSV) in 19 infants and young children with various forms of congenital heart disease. Of these, seven patients who presented with a severe illness were treated with intramuscular injections of 0.5 to 1 times 10⁶ IU per day of human leukocyte interferon (IFN) for three to five days. Intrinsic IFN activity developed before treatment in three subjects. Viral isolation studies showed active RSV infection prior to treatment, and no infectious RSV was recovered one to four days after treatment. Although there were no obvious changes in the clinical course after IFN therapy, no deaths related to RSV infection occurred. Analysis of the different types of congenital heart disease showed that ventricular septal defect and/or patent ductus arter-iosus with pulmonary hypertension were associated with the most severe RSV illness. The therapeutic value of IFN may improve in this group of subjects if it is given without delay.     

Eustachian tube patency detected by a photoelectric method

A method was developed to observe tubal orifice movement by fiberscope and detect patency of the eustachian tube by a photoelectric device (phototubometry). A highly sensitive photodiode in the external ear canal detected tube opening as increased luminosity in the tympanic cavity from a light source placed at the pharyngeal portion of the eustachian tube. The phototubometric record was superimposed on a TV screen to compare the opening in the pharyngeal portion of the eustachian tube to the tube opening during swallowing. The phototubometric records of 21 normal subjects examined by phototubometry showed the close relationship with the opened tubal lumen at the tensor veli palatini muscle (TVP) attached portion. This method is useful for examining tubal patency and observing changes in the pharyngeal portion of the eustachian tube.