No abstract

Sclerosing bone dysplasias are skeletal abnormalities of varying severity with a wide range of radiologic, clinical, and genetic features. Hereditary sclerosing bone dysplasias result from some disturbance in the pathways involved in osteoblast or osteoclast regulation, leading to abnormal accumulation of bone. Several genes have been discovered that, when disrupted, result in specific types of hereditary sclerosing bone dysplasia (osteopetrosis, pyknodysostosis, osteopoikilosis, osteopathia striata, progressive diaphyseal dysplasia, hereditary multiple diaphyseal sclerosis, hyperostosis corticalis generalisata), many of which exhibit similar pathologic mechanisms involving endochondral or intramembranous ossification and some of which share similar underlying genetic defects. Nonhereditary dysplasias include intramedullary osteosclerosis, melorheostosis, and overlap syndromes, whereas acquired syndromes with increased bone density, which may simulate sclerosing bone dysplasias, include osteoblastic metastases, Paget disease of bone, Erdheim-Chester disease, myelofibrosis, and sickle cell disease. Knowledge of the radiologic appearances, distribution, and associated clinical findings of hereditary and nonhereditary sclerosing bone dysplasias and acquired syndromes with increased bone density is crucial for accurate diagnosis.

No abstract

We evaluated 191 consecutive adults with pulmonary tuberculosis in order to develop methods to determine which patients should be initially hospitalized. Using stepwise discriminant analysis, we found the six factors that were most strongly associated with an unfavorable short-term outcome (respiratory failure or death): lymphopenia, advanced age, concomitant smear-positive extrapulmonary tuberculosis, alcoholism, a high percentage of neutrophils on the differential white blood cell count, and lack of radiographic evidence of cavitation. We derived a scoring system incorporating these variables and separated patients into high- and low-risk groups. The system was prospectively validated by applying it to a separate group of 179 patients. Lymphocyte-transformation tests in 32 patients revealed an association between clinical markers of poor prognosis and minimal lymphocyte proliferation to a heat-killed strain of Mycobacterium tuberculosis.