Profile of rhBMP-2 release from collagen minipellet and induction of ectopic bone formation

For a cylindrical controlled-release formulation using collagen as a carrier, called the minipellet (MP), which contains rhBMP-2, the relationship between the diameter of MPs and rhBMP-2 release profiles was investigated, and its effect in inducing bone formation was evaluated. Samples with three different diameters were tested for each of the following formulations: MP without additives, MP with 10% (w/w) glutamic acid (Glu) and 20% (w/w) alanine (Ala), and MP with 20% (w/w) Glu and 20% (w/w) Ala. The results of the in vitro release test and the amount of rhBMP-2 remaining in the MPs after subcutaneous implantation into mice were compared among different samples. It was found that the addition of Glu accelerated release of rhBMP-2 effectively. Release was accelerated as the diameter of MP became smaller and the amount of Glu added increased. The amount of calcium formed in 3 weeks after subcutaneous implantation into mice was dose-dependent. The amount of calcium formed per unit rhBMP-2 dose tended to increase as the diameter of MP became smaller and the amount of Glu added became greater; calcification was thus associated with release rate. These results indicate that MPs with smaller diameters induce bone formation more efficiently. For use in the treatment of fracture, etc., MP is considered to be a suitable dosage form, which can be administered noninvasively.     

Speech enhancement based on auto gain control

We propose a new method of speech enhancement based on auto gain control (AGC) using two channel inputs to deal with transient noises. Auto gain control is considered to be relatively ineffective for reducing noises that are superimposed on speech. Nevertheless, it offers advantages for addressing problems posed by musical noise and spectral distortion. This method combines two operations for obtaining accurate gain. One is spectral subtraction for two-channel input (2chSS); the other is self-offset of the noise with pre-whitening. This study also addresses a coherence based post-filter to reduce uncorrelated noise components among channels. The proposed method is evaluated in experiments across three noise conditions in which (i) impulsive noises, (ii) stationary car noise, and (iii) speech noise are present, respectively. Objective measures and spectrograms demonstrate marked improvements over other two-microphone based methods, but subjective preference tests reveal that the proposed method is less preferred than the equivalent of a nonprocessed signal in the case of stationary car noise (ii). The performance of the proposed method and the conventional 2chSS were even in the case of speech noise (iii). These results of subjective tests reflect some disadvantages of the AGC processing. Those drawbacks involve degradation of noise consistency in stationary noise conditions and residual noises in desired speech segments. Nevertheless, subjective tests in the case of noise (i) demonstrate that the proposed method is the most preferred among the methods compared here. The effectiveness of the proposed method is confirmed particularly for this noise condition.     

Binaural Localization Based on Weighted Wiener Gain Improved by Incremental Source Attenuation

This paper addresses the problem of direction-of-arrival (DOA) estimation both in azimuthal and elevation angle from binaural sound that is processed with a head-related transfer function (HRTF). Previously, we proposed a weighted Wiener gain (WWG) method for two-dimensional DOA estimation with two-directional microphones. However, for signals processed with HRTFs, peaks in the spatial spectra of WWG indicating true sources can mingle with spurious peaks. To resolve this situation, we propose to apply incremental source attenuation (ISA) in combination with WWG. In fact, ISA reduces spectral components originating from specified sound sources and thereby improves the localization accuracy of the next targeted source in the proposed incremental estimation procedure. We conduct computer simulations using directional microphones and four HRTF sets corresponding to four individuals. The proposed method is compared to two DOA estimation methods that are equivalent to two generalized cross-correlation functions and two high-resolution methods of multiple signal classification (MUSIC) and minimum variance method. For comparison purposes, we introduce binary coherence detection (BCD) to high-resolution methods for emphasizing valid spectral components for localization in multiple source conditions. Evaluation results demonstrate that, although MUSIC with BCD yield comparable performance to that of WWG in conditions where single speech source exists, WWG with ISA surpasses the other methods in conditions including two or three speech sources.     

Insecticidal compounds from Phellodendron amurense active against Drosophila melanogaster

In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, the methanolic extract of the bark of Phellodendron amurense Rupr was found to show insecticidal activity against larvae of Drosophila melanogaster Meigen. Two alkaloids, berberine (1) and palmatine (2), were isolated by bioassay‐guided fractionation of the extract. Insecticidal activity against larvae of D melanogaster was demonstrated; 1 and 2 gave LC₅₀ values of 2.44 and 8.45 µmol ml^?1 diet respectively. Acute toxicity against adult D melanogaster was also found; 1 had the more potent activity, with an LD₅₀ value of 19.0 µg per adult. However, 2 had weak activity in this study. Therefore 1 was identified as an insecticidal compound from the bark of P amurense Rupr. © 2002 Society of Chemical Industry     

Oncocytic hepatocellular carcinoma with numerous globular hyaline bodies

The current approach to the management of physician resources in Canada needs to be re-examined by all concerned. Canada is about to enter a phase of accelerating depletion of physicians as the result of two separate and evolving circumstances. Because of the unusually large number of physicians who graduated from Canadian medical schools in the late 1960s and early 1970s, a significantly larger than usual number of practising physicians will reach their normal retirement age in the decade ahead. In addition, if the recent surge in the emigration of Canadian physicians continues, the loss of so many physicians will exaggerate the impact of the expected increase in retirements. Therefore, the decision to cut medical school class sizes in the 1990s would have been more suitable in the early 1980s. Existing physician work force policies may be leading to unexpected or undeclared consequences for health care across Canada. On the basis of current trends, the author concludes that policy makers now should reconsider current physician workforce policies in anticipation of a possible shortfall of physicians beginning in the early decades of the next century.     

Relationship between response to interferon therapy and detection of hepatitis C virus RNA by differential flotation centrifugation

Problem-based learning (PBL) is a method of instruction gaining increased attention and implementation in medical education. In PBL there is increased emphasis on the development of problem-solving skills, small group dynamics, and self-directed methods of education. A weekly PBL conference was started by a university consultation psychiatry team. One active consultation service problem was identified each week for study. Multiple computerized and library resources provided access to additional information for problem solving. After 1 year of the PBL conference, an evaluation was performed to determine the effectiveness of this approach. We reviewed the content of problems identified, and conducted a survey of conference participants. The most common types of problem categories identified for the conference were pharmacology of psychiatric and medical drugs (28%), mental status effects of medical illnesses (28%), consultation psychiatry process issues (20%), and diagnostic issues (13%). Computerized literature searches provided significant assistance for some problems and less for other problems. The PBL conference was ranked the highest of all the psychiatry resident educational formats. PBL appears to be a successful method for assisting in patient management and in resident and medical student psychiatry education.     

Helicobacter pylori infection

CHROMagar, a chromogenic differential culture medium, is claimed to facilitate the isolation and presumptive identification of certain clinically important yeast species, e.g., Candida albicans. This study evaluated the cost-effectiveness and time advantage of using it in comparison with Sabouraud dextrose agar (SDA). Three possible pathways, each of which included the use of one or both media, were compared in a routine laboratory. A total of 21 yeast isolates was cultured from 298 clinical samples from neutropenic and AIDS patients. An overall sensitivity of 95.2% was observed for each medium and primary isolation on CHROMagar was found to be 100% sensitive and 100% specific for C. albicans. For identification purposes, after initial culture the use of CHROMagar provided the most economical and least time-consuming method. Direct inoculation on to CHROMagar is recommended for blood cultures when yeast cells are seen on microscopy and where early appropriate therapy is imperative.     

Neurocutaneous melanosis with intracranial malignant melanoma in an adult: a case report

A 65-year-old female with congenital giant, hairy and pigmented nevus developed sudden onset of headache and consciousness disturbance. CT scan revealed a high density mass in the right temporal subcortical region. The high density area suggested hematoma. A right temporal craniotomy was performed. Hemorrhage was observed in a black colored tumor. Histologically, the tumor was malignant melanoma, while the skin tumor was benign intradermal nevi. This patient was diagnosed as neurocutaneous melanosis. Neurocutaneous melanosis belongs to unusual congenital syndrome, and an adult case is very rare. To our knowledge this is the oldest patient to be reported with this disease.