Preliminary experience with beta-tricalcium phosphate for use in mastoid cavity obliteration after mastoidectomy.

OBJECTIVE: To examine the efficacy and safety of mastoid cavity obliteration using highly purified beta-tricalcium phosphate (beta-TCP) after mastoidectomy in middle ear surgery. PATIENTS: Thirteen patients with cholesteatoma invading the mastoid cavity or showing severe pathologic changes in the mastoid cavity. INTERVENTION: Twelve patients underwent mastoid obliteration with highly purified beta-TCP during the first- and/or second-stage operation of a 2-stage canal-up operation: 5 patients during the first and second stages, and 7 patients during the second stage only. One patient with cholesteatoma underwent mastoid obliteration with highly purified beta-TCP during a 1-stage canal-up operation. In total, beta-TCP was applied in 18 ear operations. MAIN OUTCOME MEASURES: All patients underwent multislice computed tomography (CT) before and after surgery to assess the condition of the middle ear. The amount of residual beta-TCP granules in the mastoid cavity was assessed using the following granular shadow grading scale: Grade 0, no granular shadow in the mastoid cavity; Grade 1, residual granular shadows in part of the mastoid cavity; and Grade 2, granular shadows in most of the mastoid cavity. To assess any harmful effect of beta-TCP implanted in the mastoid cavity, continuous postoperative discharge and delayed wound healing were recorded. In addition, the bone conduction threshold was assessed using pure-tone audiometry, and the patients were asked whether they experienced vertigo or dizziness during the postoperative follow-up. RESULTS: All the patients who underwent multislice CT less than 11.4 months after mastoid cavity obliteration with beta-TCP were Grade 2 on the granular shadow grading scale, whereas all those who underwent multislice CT more than 53.8 months after mastoid obliteration were Grade 0. No patient had continuous postoperative discharge, delayed wound healing, or extrusion of beta-TCP granules. No patient showed deterioration of the bone conduction threshold more than 10 dB after mastoid cavity obliteration with highly purified beta-TCP or complained of postoperative vertigo or dizziness. CONCLUSION: Highly purified beta-TCP may be safe and reliable for mastoid obliteration. Highly purified beta-TCP may also be useful in other surgical procedures, including posterior wall reconstruction of the external auditory canal and scutum plasty.     

Joint Gap in Mid-Flexion Is Not a Predictor of Postoperative Flexion Angle After Total Knee Arthroplasty

Background

Postoperative knee flexion angle is one of the most important outcomes of total knee arthroplasty (TKA). Intraoperative ligament balancing may affect the postoperative range of motion of the knee. However, the relationship between intraoperative ligament balancing and postoperative flexion angle was still controversial. The purpose of this study was to determine whether intraoperative joint gap affects postoperative knee flexion angle or not.

Interferon-gamma inhibition of interleukin 4-induced hyperproliferation of resting B cell from NZB/NZW F1 mice.

To characterize B cell hyperactivity in autoimmune NZB/NZW (B/W) F1 mice, we studied the effects of murine recombinant interferon gamma (IFN-gamma) on interleukin 4 (IL-4) induced resting B cell growth and differentiation. The number of resting B cells of B/W F1 mice were decreased, with more sensitivity to IL-4 than normal mice. Thus, resting B cell hyperresponsiveness to IL-4 was in a dose-dependent manner suppressed by IFN-gamma. This action was most noticeable when IFN-gamma was added to the culture system simultaneously with IL-4. As well, IFN-gamma did not exhibit cytotoxicity. These results suggest that IFN-gamma may have regulatory effects on IL-4 mediated B cell triggering.     

Effects of intracoronary injection of acetylcholine on coronary arterial hemodynamics and diameter

To examine the effects of intracoronary injection of acetylcholine on coronary blood flow and on coronary arterial diameter in humans, acetylcholine was injected into the left coronary artery in 32 adult patients (21 men and 11 women with a mean age of 54 years, range 37 to 65) with normal or almost normal coronary arteriographic findings. Patients with angina pectoris, myocardial infarction and severe cardiac diseases were excluded. Temporary right ventricular pacing was set at a rate of 60 beats/min to prevent transient bradyarrhythmias during intracoronary injection of acetylcholine. Measurements of coronary sinus blood flow and coronary vascular resistance and quantification of coronary arterial diameters using a computer-assisted technique were performed before and after each injection of 20, 50 and 100 micrograms of acetylcholine. Significant increase in coronary sinus blood flow and significant decrease in coronary vascular resistance occurred after intracoronary injection of acetylcholine. In contrast, mean diameter of normal epicardial coronary artery tended to decrease and that of irregular epicardial coronary artery decreased significantly after intracoronary injection of acetylcholine. Intracoronary injection of acetylcholine increases coronary blood flow, suggesting vasodilation in the coronary arteriolar bed, while it induces vasoconstriction in most of epicardial coronary arteries in adult humans.     

Advances in Management of Retinoblastoma

Retinobiastoma is a highly malignant intraocular tumor of children that requires accurate diagnosis to prompt treatment. This article reviewed clinical, pathological and follow-up data on 1 147 cases of retinobiastoma registered in Japan from 1975 to 1982. It is obvious that the prognosis of children with retinobiastoma has improved remarkably in recent years. The current advances in the management of the retinobiastoma were discussed.     

Analysis of retinal findings of acute retinal necrosis using optical coherence tomography

PURPOSE: To analyze the retinal findings in patients with ARN, optical coherence tomography (OCT) was performed. METHODS: Seven patients (7 eyes) with ARN were studied using OCT. RESULTS: OCT images depicted highly reflective areas in the inner layers of the retina in all seven cases, corresponding with the yellowish-white lesions of the retina in the acute phase. Disorganization of the retinal structure was also observed in these retinal lesions, especially in cases with severe inflammation. Subretinal changes including retinal exudate and/or fluid were observed in only one case. After regression of the yellowish-white lesions in the retina, a significant reduction in retinal thickness was observed on OCT. CONCLUSIONS: OCT permits the detection of full-thickness retinal necrosis in the acute phase and complete absence of retinal structure in the resolution phase, corresponding with the yellowish-white lesions seen in patients with ARN.