Giant-cell tumor of the bone

The giant-cell tumor of bone (GCT) is an aggressive benign, potentially malignant lesion, which biological behaviour is unpredictable. Its aggressivity is usually increasing through the recurrences and is related to the mitotic activity, the excessive metalloproteinase expression and to the alterations in different oncogens of the tumor cells. Statistically, 80% of the GCT-s have a benign course, with a local recurrence rate of 10-50%; about 10% of GCT-s undergo malignant transformation through their recurrences and 1-4% give pulmonary metastases even in case of a benign histology. Despite of the frequent recurrences, adequate treatment results in 96% to 98% cure in patients with GCT. The goal of surgery should be both in primary and recurrent cases: joint-sparing and careful curettage with use of adjuvants (bone cement and phenol, etc.) for decreasing the rate of recurrences. Resection is only in case of extensive joint destruction or malignancy indicated. Radiotherapy with modern supervoltage equipment minimalized the occurrence of secondary malignant transformation, however, its use is only in locations difficult for surgery (vertebra, sacrum, pelvis) recommended.     

骨龄与骨密度关系的初步探讨

目的:探讨儿童骨龄与骨密度的关系,为骨龄的评估提供一种新方法。方法:采用双能X线吸收法(DXA)测定698名6～14岁儿童手腕部骨密度和采用TW2法对左手腕骨平片计算儿童骨龄。结果:6～14岁儿童骨龄与骨密度、年龄均呈正相关关系。结论:对儿童进行骨密度的测量可以初步预算儿童骨龄。     

A hearing aid anchored in the cranial bone for amplification of bone conduction

The purpose of this study was to compare hearing and understanding with a bone conduction hearing aid of a new type and with conventional models. The new instrument, BAHA (bone anchored hearing aid) is connected with the skull percutaneously rather than transcutaneously as with the conventional instruments. In the ENT department of Nijmegen University Hospital the understanding of speech with both types of hearing aid was evaluated thoroughly. The patients had a middle-ear loss with in addition an inner-ear loss of 60 dBHL at most. A conventional air conduction hearing aid (behind or inside the ear) was unsuitable for them because of, for instance, chronic runny ears or anomalies of the auditory meatus. A conventional bone conduction hearing aid containing a transducer pressing on the skin was rejected because of poor understanding or serious side effects such as headache and pressure pains. At the first session a titanium screw was implanted in the skull behind the ear. The percutaneous superstructure was put into place a few months later at a second session. In none of the patients were there peroperative problems or postoperative infections of any importance. Understanding of speech in silence and in noise was evaluated with the BAHA and with the conventional aid. Differences in understanding of speech were regarded as significant if they amounted to more than twice the known intra-individual standard deviation. As to understanding of speech in silence, 7 of the 15 patients were found to understand significantly better with the BAHA than with a conventional aid. In the other patients no difference was found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Drugs and the bone marrow

Some drugs have a predictable suppressive effect upon the bone marrow and are used in the treatment of malignant disease. Others are unpredictable and may cause unanticipated side effects to bone marrow during the treatment of non-malignant pathologies. In this article, bone marrow maturation is discussed and both the defined and potential effects of drugs upon the bone marrow are considered.     

Effect of calcium supplementation to undernourished mothers during pregnancy on the bone density of the bone density of the neonates

Eighty seven pregnant women belonging to poor socioeconomic groups of population were investigated to find out the effect of calcium supplementation during pregnancy on the bone density of the mother as well as of the neonate. Supplements of 300 and 600 mg of elemental calcium administered daily from the 20th week of gestation onward until term, brought about a significant increase in the bone density of the neonates born of such mothers compared to that of the neonates born to unsupplemented mothers. Although no significant difference was observed between the initial and final values for bone densities among the mothers, there was a tendency for an increase in the bone density of the mothers who received 600 mg of calcium supplements. Individual variation of different neonatal bones in their response to maternal calcium supplements was observed. Bone density of the neonate was not related to the birth weight, crown-heel, or crown-rump lengths.     

The differential diagnosis of polycythaemia--a bone marrow study (the bone marrow in polycythaemia)

Bone marrow sections from posterior iliac crest aspiration and/or trephine specimens have been examined in 39 patients with true polycythaemia, along with a variety of other clinical and laboratory data. The emphasis has been on objective assessment of cellularity and megakaryocyte concentration in a prospective four year study. In patients with untreated primary polycythaemia mean cellularity was 87.0% and 86.4% for aspirate and trephine specimens compared with 55.5% and 48.7% for secondary cases and 48.3% and 45.5% for controls. Eighty per cent of primary polycythemia patients had moderate to marked megakaryocytic hyperplasia. We conclude that, in the presence of an elevated red cell volume, marrow cellularity of greater than 75%, particularly when accompanied by megakaryocytic hyperplasia, of iliac crest aspirate or trephine specimens is sufficient per se to establish a diagnosis of polycythaemia rubra vera.